Prosthesis doi: 10.3390/prosthesis8050049

Authors: Maria Tsiafitsa Petros Mourouzis Dimitrios Dionysopoulos Pantelis Kouros Kosmas Tolidis

Objectives. This study evaluated the performance of three intraoral scanners with different acquisition technologies in detecting early signs of tooth wear, using micro-computed tomography (micro-CT) as the reference standard. Methods and Materials. Three IOS were examined, including an active triangulation scanner, a structured-light triangulation scanner, and a parallel confocal technology scanner. Ten extracted unrestored and caries-free premolars were placed in the maxillary left second premolar position of a dental mannequin and scanned at baseline, generating quadrant digital models. Micro-CT scans were also obtained at baseline. Wear was simulated by immersion in a 1% citric acid solution followed by brushing of the buccal surfaces. All specimens were rescanned with IOS and micro-CT. Micro-CT datasets were reconstructed into stereolithography models and compared with IOS models using mesh analysis software. Statistical analysis was performed in R using linear mixed-effects models to account for repeated measurements across teeth. RMS values and absolute errors relative to the micro-CT reference were analysed with device as a fixed effect and tooth as a random effect, with Tukey-adjusted pairwise comparisons. Repeatability was additionally assessed from the repeated scans using within-tooth variability. Results. Significant differences were observed among the evaluated systems in the detection of changes related to tooth wear (p < 0.001). The micro-CT reference showed the lowest RMS value, followed by Trios 3, Primescan, and Omnicam. Model-based analyses confirmed significant differences among the evaluated systems, while the magnitude and statistical support of pairwise contrasts depended on the specific outcome considered. Repeatability analysis showed that Trios 3 had the lowest within-tooth standard deviation and repeatability coefficient (0.0215 mm and 0.0595 mm, respectively), followed by Primescan (0.0290 mm and 0.0802 mm), whereas Omnicam showed the highest within-tooth variability and repeatability coefficient (0.0624 mm and 0.173 mm). Conclusions. The parallel confocal and structured-light triangulation intraoral scanners produced RMS values numerically closer to the micro-CT reference than the active triangulation scanner. However, none of the evaluated intraoral scanners demonstrated quantitative agreement sufficient to be considered interchangeable with the reference standard.

Prosthesis doi: 10.3390/prosthesis8050048

Authors: Natalia Blanch-Martínez Anabel Gramatges-Rojas Carmen Ferrer-Serena Santiago Arias-Herrera

Background/Objectives: The development of high-performance biocompatible polymers such as zirconium-reinforced polyether ether ketone (BioHPP®) has expanded the range of materials available for implant-supported prostheses, traditionally limited to metal alloys and zirconia. Due to its favorable mechanical properties and elastic modulus similar to cortical bone, BioHPP® has been proposed as a potential alternative in implant prosthodontics. This systematic review aimed to analyze the biomechanical behavior of zirconium-reinforced PEEK and assess its advantages and limitations in implant prosthetic applications. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines, including studies published between 2011 and 2025 that evaluated the performance of BioHPP in implant prosthetic applications. Results: The search strategy identified 34 studies that met the inclusion criteria. The included studies evaluated mechanical properties such as fracture resistance, elastic modulus, stress distribution, and peri-implant tissue response. Zirconium-reinforced PEEK demonstrated fracture resistance values reaching up to 1623.31 N and an elastic modulus of approximately 4 GPa, comparable to cortical bone. Several studies also reported favorable stress distribution patterns and reduced mechanical complications when compared with conventional metallic materials. Conclusions: Zirconium-reinforced PEEK exhibits promising biomechanical characteristics for use in implant-supported prostheses, particularly due to its fracture resistance and bone-like elastic modulus. However, the available evidence is predominantly based on in vitro and finite element studies. Long-term clinical trials are required to confirm its clinical performance and establish definitive recommendations for routine use.

Prosthesis doi: 10.3390/prosthesis8050047

Authors: Justine Sanslaville Andres Pauline Dussueil Nicolas Lamy Ramzi Ouadah Hervé Moizan

Background: Rehabilitation of edentulous mandibles in a post-oncologic setting remains a major clinical challenge. In such situations, placement of conventional endosseous implants may be compromised by severe bone deficiency, a history of peri-implant infection, and constraints related to reconstructive soft tissues. Customized titanium subperiosteal implants, made possible by three-dimensional imaging, computer-aided design, and additive manufacturing, represent a potential alternative when conventional options are unfavorable. This case report describes a full-arch fixed rehabilitation of an edentulous mandible in a patient previously treated for squamous cell carcinoma of the floor of the mouth. Methods: A patient-specific titanium additively manufactured subperiosteal jaw implant (AMSJI) made of biocompatible titanium was designed using a digital planning workflow. Implant placement was performed in a single surgical session under general anesthesia, with fixation using osteosynthesis screws. A screw-retained full-arch provisional prosthesis was delivered intraoperatively, allowing immediate loading with adjustments aimed at avoiding compression of the healing soft tissues. Results: The patient achieved satisfactory functional and esthetic rehabilitation. Postoperative follow-up showed overall favorable mucosal tolerance; an early, limited peri-abutment mucosal dehiscence was observed and managed with suturing under local anesthesia, without compromising implant stability. Conclusions: This case highlights the clinical interest of patient-specific titanium subperiosteal implants as a fixed rehabilitation option in post-oncologic patients with major osseous and mucosal constraints and a history of reconstructive procedures. The combination of accurate digital planning and custom-made manufacturing may avoid the need for extensive bone grafting. However, these findings should be interpreted with caution due to the short-term follow-up and the inherent limitations of a single-case report, which limit the level of evidence and generalizability.

Prosthesis doi: 10.3390/prosthesis8050046

Authors: Natascha Raisig Frank Traub Per Otto Schüller Andreas Hahn Johannes Schröter

Background/Objectives: Despite growing evidence of benefit, microprocessor-controlled knees (MPKs) are not routinely integrated into standard rehabilitation pathways for low-mobility (K-Level 1–2) transfemoral amputees. This exploratory analysis aimed to characterize functional trajectories of low-mobility amputees associated with early versus delayed or no MPK provision in routine inpatient rehabilitation. Methods: This prospective observational multicenter study evaluated 24-week functional trajectories in low-mobility transfemoral amputees receiving standard inpatient rehabilitation at seven non-specialized centers in Germany. Participants were grouped post hoc into two groups: (1) early MPK provision (initial Kenevo use) and (2) delayed or no MPK provision (initial non-microprocessor knees with or without later transition). Patient-reported mobility (PLUS-M K2), health-related quality of life (EQ-5D-5L), and social reintegration (RNLI) were assessed across multiple time points during inpatient rehabilitation and follow-up. Analyses were descriptive and exploratory due to small sample size. Results: Nineteen participants were included. Across outcomes, the early MPK group showed more consistent improvements over time, whereas the delayed/no MPK group demonstrated more variable trajectories with less sustained gains. Conclusions: In this exploratory real-world cohort, early provision of a K2-specific MPK (Kenevo) was associated with more favorable functional trajectories compared with delayed or no MPK provision. Given the small sample size, post hoc group allocation, and potential confounding by indication, these findings should be considered hypothesis-generating. Larger prospective studies are required to evaluate the timing and role of MPK provision in low-mobility populations.

Prosthesis doi: 10.3390/prosthesis8050045

Authors: Mohammad Qaddomi Manar Metlej Ghanem Arbid Erta Xhanari Hani Tohme

This case report describes a digital workflow for the aesthetic rehabilitation of a 30-year-old male patient with unaesthetic anterior teeth. The treatment incorporated AI-assisted smile design software (SmileCloud Biometrics) for 2D/3D digital planning and patient communication. Six lithium disilicate veneers (IPS e.max CAD) were fabricated using CAD/CAM technology following mock-up-guided minimally invasive preparation (0.2–0.9 mm reduction). The restorations were adhesively cemented under rubber dam isolation. One-week follow-up confirmed aesthetic integration, occlusal harmony, and patient satisfaction. This case illustrates how digital workflows with AI-assisted tools can support veneer rehabilitation through data-informed planning and conservative preparation while maintaining aesthetic outcomes.

Prosthesis doi: 10.3390/prosthesis8050044

Authors: Federico Tirone Stefano Salzano Erik Rolando

In this study, a fully digital workflow enabling the alignment of pre- and postoperative mandibular intraoral scans in complete-arch implant rehabilitation using intraosseous fiducial reference markers is presented. A prosthetically driven digital workflow was implemented for mandibular complete-arch rehabilitation in which two cylindrical intraosseous pins were placed in a median or paramedian mandibular region and used as fiducial reference markers to align pre- and postoperative intraoral scans. Pin osteotomies were prepared using a calibrated drilling protocol and preserved throughout surgery to allow for the exact repositioning of the pins. Implant positions were recorded using photogrammetry, while postoperative intraoral scans were acquired after suturing with the pins reinserted. Scan alignment was performed using a best-fit algorithm based exclusively on the fiducial pin geometry. Standardized convergent scanbodies without undercuts were used for intraoral scanning. The proposed workflow allowed for the alignment of pre- and postoperative mandibular scans without additional radiographic acquisitions and was compatible with both guided and free-hand implant placement, regardless of the degree of mandibular atrophy. Within the limitations of a proof-of-concept report, the use of intraosseous fiducial reference markers represents a minimally invasive and clinically applicable solution to a critical limitation of fully digital mandibular rehabilitation workflows, without the quantitative validation of accuracy, trueness, or reproducibility.

Prosthesis doi: 10.3390/prosthesis8050043

Authors: Hanin Alsalhi Rana Altuwajri Ali Alenezi

Objectives: Endodontic complications are among the most frequently reported biological complications in tooth-supported fixed dental prostheses (FDPs). The aim of this study was to evaluate the prevalence of periapical complications in FDPs placed on vital and non-vital abutments and to identify risk factors for these lesions. Methods: This retrospective clinical trial was conducted on participants who had attended routine follow-up visits at the dental hospital at Qassim University, Saudi Arabia. Participants were examined clinically and radiographically for the presence of periapical lesions. Information was recorded on the design, material, location of the prostheses, and oral hygiene. The survival and lesion-free survival rates were determined using the Kaplan–Meier method. Life-table analysis was performed to assess the mean time to event. Univariate Cox proportional hazards regression analysis was used to assess potential risk factors for the development of periapical lesions (α = 0.05). Results: A total of 495 FDPs were placed in 302 participants, with a mean age of 45.7 ± 13.4 years and a mean follow-up period of 7.5 ± 6.5 years. Lesions were detected in 32.3% of FDPs during follow-up. There were no significant differences in the prevalence of lesions in vital compared with non-vital abutments or between males and females (p > 0.05). Poor oral hygiene was the most significant risk factor for the development of periapical lesions (p < 0.05). Univariate Cox regression analysis showed that anterior–posterior FDPs had a higher risk of lesions (p = 0.035). No significant associations were found between lesions and the material used or the design of the abutment (p > 0.05). Conclusions: Periapical complications in FDPs are mainly influenced by oral hygiene and the location of the FDPs, whereas abutment vitality and material type appear to have limited impact.

Prosthesis doi: 10.3390/prosthesis8040042

Authors: Salah A. Yousief Hend Mohamed Elsayed Abdulrazak Mahmoud Fayed Roua Mohammed Y. Almadani Mohammad Abdullah Alqhtani Ahmed Mohammed Sleem Abdelglel Khalid Dhafer Alhendi Sokina Yosef Abdulmalik Sarah Salah Gaafar Ahmed Ibrahim Mahrous Ebaa Ibrahim Alagha Mahmoud Darwish

Background and aim: The influence of fabrication techniques, cement type, and cyclic loading on the marginal adaptation of lithium disilicate crowns remains a clinical concern that may affect their long-term performance. This study aimed to evaluate the effects of cyclic loading and cement type on the marginal fit of milled and pressed lithium disilicate crowns. Methods: Twenty lithium disilicate crowns were fabricated and divided into two groups based on the manufacturing technique: milled and pressed (n = 10 each). Each group was further subdivided according to the cement type: resin or resin-modified glass ionomer (n = 5 per group). Crowns were cemented on standardized epoxy resin dies, and the marginal gap was measured using a stereomicroscope before and after cyclic loading. Cyclic loading was performed at 50 N for 37,000 cycles. Data were statistically analyzed using a three-way ANOVA (α = 0.05). Results: Milled crowns showed marginal gaps ranging from 52 to 57 µm, whereas the pressed crowns exhibited smaller gaps ranging from 39 to 47 µm. Neither the cement type nor the cyclic loading produced a significant difference in the marginal gap values (p > 0.05). Conclusions: Pressed lithium disilicate crowns exhibited superior marginal adaptation compared with the milled crowns. Neither the type of cement nor the cyclic loading had a significant effect on the marginal gap. Both fabrication techniques yielded clinically acceptable fits (<100 µm).

Prosthesis doi: 10.3390/prosthesis8040041

Authors: Elena-Raluca Baciu Cezara Andreea Onică Alice Murariu Gabriela Luminița Gelețu Costin Iulian Lupu Cezar Ilie Foia Neculai Onică

Advanced cases of unilateral condylar hyperplasia might need combined joint reconstruction and orthognathic surgery. This report illustrates the feasibility of integrating digital planning, patient-specific prosthesis design, and orthognathic correction within a single-stage surgical workflow. A 23-year-old female patient presented with skeletal Class III malocclusion, facial asymmetry, and mandibular midline deviation due to left condylar hyperplasia. After preoperative orthodontic alignment, virtual surgical planning was carried out using specialised software to simulate resection of the hyperplastic condyle, with concurrent total TMJ replacement, contralateral sagittal split ramus osteotomy, and Le Fort I osteotomy. Based on this plan, patient-specific prosthetic components, surgical guides, and fixation plates were designed and manufactured. Surgery was performed according to the digital plan using a combined intraoral and extraoral approach. At 3-month follow-up, clinical and radiological assessments showed stable prosthesis positioning, improved occlusal relationships, restoration of facial symmetry, and high patient-reported satisfaction. However, given the single-case design and short follow-up, these findings should be considered preliminary, and further studies are necessary to evaluate long-term functional outcomes and reproducibility.

Prosthesis doi: 10.3390/prosthesis8040040

Authors: Anton Kurakin Anton Sergeev Darya Korostovskaya Anna Kurenkova Vladimir Serdyukov

Background/Objectives: The modern prosthetic foot market is characterized by a pronounced polarization between affordable but low-function devices and high-performance yet costly composite prostheses. The aim of this study was to develop and comprehensively evaluate cost-effective, functional prosthetic feet manufactured by fused deposition modeling (FDM). Methods: An iterative design methodology was employed, combining finite element analysis to optimize the biomechanical response of the device, the incorporation of user-specific requirements and experimental validation. Two TPU 95A-based 3D-printed prosthetic foot designs were designed and developed, and their strength and functional characteristics were assessed numerically under the ISO 22675:2024 normative loading cycle. Bench-top mechanical tests were conducted on the fabricated prototypes. Functional performance was evaluated by a transtibial amputee using an inertial motion capture system to analyze gait kinematics. Results: The results demonstrated that both designs operate predominantly within the elastic range with an adequate safety margin. The pilot feasibility gait assessment indicated feasibility and plausibility within the tested protocol and participant for both prototypes. Conclusions: The developed TPU 95A-based FDM prosthetic feet demonstrated promising structural integrity and functional feasibility, supporting the potential of low-cost additive manufacturing as a viable approach for producing affordable prosthetic feet. Further studies with larger participant cohorts and extended testing are needed to confirm clinical applicability and long-term performance.

Prosthesis doi: 10.3390/prosthesis8040039

Authors: Ada Ferrer-Fuertes Francisco Javier Cuesta-González Ramón Sieira-Gil Alberto Prats-Galino Samir Aboul-Hosn Centenero Eloy García-Díez Laura Pozuelo-Arquimbau Pau Rodriguez-Berart Irene Vila-Masana Bilal AlOmari Carles Marti-Pagés

Background: Severe trismus and post-oncologic maxillary defects often prevent conventional zygomatic implant placement. This study evaluates a novel implant specifically designed for reverse insertion (from the zygoma toward the oral cavity) and assesses its feasibility and accuracy in a cadaveric model. Materials and Methods: A Brown Class II maxillectomy was simulated in a fresh-frozen cadaver. Four custom reverse zygomatic implants were virtually planned and placed using CAD/CAM surgical guides. Superior and inferior orbital approaches were compared. Postoperative CT was superimposed onto the preoperative plan to measure linear and angular deviations, and a 3D-printed verification bar assessed prosthetic alignment. Results: All implants were successfully inserted with primary stability and without compromising critical structures. The superior orbital approach yielded lower deviations and better guide stability, which was reflected in the results: deviation at the zygomatic bone was 1.25 mm in the superior approach vs. 2.32 in the inferior approach, intraorally 4.7 mm vs. 7.3 mm, and angular deviation 1.85° vs. 5.63°. Despite minor distal deflection, intraoral emergence remained within clinically acceptable limits, allowing partial seating of the verification bar. Conclusions: Reverse-insertion zygomatic implants are technically feasible, anatomically safe, and compatible with fixed prosthetic rehabilitation in cases where conventional placement is impossible. Penetrating the orbit, injuring the skin or the infraorbital nerve could be possible but guided surgery seems to prevent them. A forthcoming clinical series of eight additional cases will further validate this protocol.

Prosthesis doi: 10.3390/prosthesis8040038

Authors: Michał Krupa Joachim Pachucki Iga Wiak Rafał Zabłoński Paweł Kasprzak Łukasz Pulik Paweł Łęgosz

Patellar maltracking is among the most common causes of anterior knee pain after total knee arthroplasty (TKA), underscoring the need for accurate prevention and treatment. Therefore, the purpose of this narrative review is to provide a comprehensive overview of current evidence on post-TKA tracking, focusing on component alignment, preoperative patient assessment, and revision treatment options. A PubMed database search was performed, leveraging the literature from the last 20 years, and the results were qualitatively synthesized. According to current studies, several precautions should be taken to prevent patellofemoral stress and, consequently, patellar maltracking, such as avoiding internal rotation, valgus alignment, and excessive flexion of the femoral component and internal rotation of the tibial component. Regarding alignment strategies, kinematic alignment appears to offer potential benefits over mechanical alignment in certain functional outcomes and patient satisfaction scores. However, these differences should be interpreted cautiously as they may not always exceed the minimal clinically important difference. Furthermore, recent evidence indicates that quadriceps biomechanics influence TKA outcomes, potentially suggesting that conventional surgical approaches may need to be individualized, though these preliminary findings require prospective validation. Currently, robotic-assisted surgery represents a developmental direction for patient-tailored interventions and offers great promise for better prosthesis customization to the individual patient. Integration of imaging data with dynamic soft-tissue assessment enables more predictable reconstruction of joint kinematics. Regarding surgical treatment, the selection of specific methods requires a prior clinical and radiographic assessment. Indications range from patellar maltracking direction and component malrotation to patient preferences and rehabilitation potential. Ultimately, the future of TKA relies on personalized interventions to prevent complications and improve patient outcomes. This evolution is driven by the shift from mechanical alignment to kinematic alignment, alongside quadriceps tendon assessment and intraoperative robotic-assisted measurement, all aimed at optimizing the accuracy of implant positioning.

Prosthesis doi: 10.3390/prosthesis8040037

Authors: Donatas Daublys Joseph Janosky Linas Puodžiukynas Aurelijus Domeika

Background/Objectives: Prosthesis optimization after transfemoral amputation is often guided by clinical experience, yet quantitative evidence isolating how prosthesis mass, inertial properties, and alignment affect mechanical load transmission remains limited. Musculoskeletal modeling can be used as a controlled framework for examining relative sensitivity rankings of constraint force transmission across prosthetic junctions under fixed gait inputs. Methods: A model was modified to incorporate a transfemoral prosthesis. Experimental walking data from a healthy adult reference subject (Qualisys motion capture, synchronized AMTI force plates) provided kinematics and ground reaction forces for model scaling, inverse kinematics, and loading. These inputs provided a standardized mechanical reference and were not intended to represent transfemoral amputee gait. Prosthesis mass (2.625, 3.50, 4.375 kg), inertia (0.5×, 1.0×, 1.5×), and mediolateral alignment (−10, 0, +10 mm) were varied while keeping kinematics and ground reaction forces identical across conditions. Constraint reaction forces at the socket–residual limb junction and prosthetic ankle were computed and normalized to body weight. Results: Increasing mass produced the largest monotonic increases in peak resultant constraint reactions, most prominently at the socket-level junction (8.51 → 10.48 → 12.29 BW), with smaller changes at the ankle and unchanged peak timing. Inertia caused joint-specific effects, whereas mediolateral alignment minimally affected constraint reaction forces and redistributed force components. Conclusions: This study quantified the one-factor-at-a-time effects of prosthesis mass, inertia, and mediolateral alignment on inter-segment constraint reaction forces. The reported reactions should be interpreted as net rigid-body constraint reactions under fixed inputs, not as physiological joint contact forces or direct interface loads.

Prosthesis doi: 10.3390/prosthesis8040036

Authors: Chethan K N John Valerian Corda Laxmikant G. Keni M. Kalayarasan Jonathan Reginald Sudhir Jain Prathik

Background/Objective: Traditional hip implant evaluations often overlook patient-specific dynamic loadings. This study investigates the performance of novel collared hip implant designs under walking conditions, focusing on geometric profiles and two common stem materials: Ti-6Al-4V and CoCr alloy. Methods: Patient-specific dynamic forces were applied using commercial finite element analysis, adhering to ISO and ASTM standards. Four cross-sectional profiles—circular, elliptical, oval, and trapezoidal—were initially evaluated for induced stresses and displacements. Subsequently, wear characteristics at implant junctions were analyzed, comparing CoCr (MC 1) and Ti-6Al-4V (MC 2) stems. The study also assessed the impact of using Ultra-High Molecular Weight Polyethylene (UHMWPE) acetabular cups. Results: The elliptical (CS 2) cross-sectional profile demonstrated superior performance. Junction analysis revealed that the CoCr stem (MC 1) exhibited a stem-to-head sliding distance four times higher and contact pressure 5.5 times higher than the Ti-6Al-4V stem (MC 2). Specifically, MC 1 showed 82% higher contact pressure and 89% greater sliding distance at the stem–head junction compared to MC 2. Additionally, utilizing UHMWPE cups effectively eliminated squeaking sounds attributed to CoCr cups due to superior wear resistance. Conclusions: The combination of an elliptical (CS 2) cross-sectional profile with a Ti-6Al-4V stem and UHMWPE acetabular cup offers optimal performance. This configuration significantly reduces wear and contact pressure, suggesting enhanced functionality and durability for hip implants under dynamic loading conditions.

Prosthesis doi: 10.3390/prosthesis8040035

Authors: Sara Ghasemi Rad Abiyaneh Reza Hashemi Corinne Archer Khashayar Ghadirinejad

Background: Total joint arthroplasty (TJA) is one of the most successful surgical procedures for patients to improve the quality of life. In recent years, the use of machine learning (ML) in the setting of arthroplasty decision-making has grown. Methods: This article reviewed studies published between 2020 and 2025 that applied ML to TJA, with a focus on the limitations reported by these studies. A search in ScienceDirect identified 220 articles. After screening and full-text assessment, 17 studies met the inclusion criteria, excluding imaging-based research, to focus on predictive models trained on non-image clinical data. Results: The reviewed studies revealed several common limitations, categorised into four groups, including observations and follow-up (30.3% of the studies), dataset quality and design (27.3%), model transferability and generalisation (27.3%), and outcome measurement and interpretation (15.2%). These limitations impact the reliability and real-world relevance of ML models in the context of arthroplasty. This article also provides suggestions to help researchers address these limitations in future studies. Conclusions: This review provides an overview of the potential limitations associated with the development of ML models within the TJA community in order to identify the gaps and challenges to improve the quality of research and possibly decision-making support systems using joint arthroplasty clinical datasets.

Prosthesis doi: 10.3390/prosthesis8040034

Authors: Amjad Nuseir Muhanad M. Hatamleh Grainne McGinnity-Hamze Jason Watson

Background: Auricular keloids and ear helix deformities are undesirable and aesthetically unpleasing deformities that can cause significant patient psychologic and self-esteem problems. Pressure therapy for keloids is well documented to be an effective non-invasive treatment modality. However, current devices lack comfort and aesthetic appeal to deliver the pressure forces required effectively and uniformly. This work aims to highlight some different pressure therapy approaches for the management of keloids and irregularities in the ear helix morphology. Methods: A case series of four patients presenting with auricle keloids of various sizes and at different locations secondary to ear piercing and one case of congenital helix deformity were treated successfully with pressure therapy devices. The device designs varied based on the keloids’ characteristics and patients’ preferences and involved wire-based spring-activated appliances resembling ear rings for moderate keloid lesions, modified double-spring systems for large or elongated lesions, and magnet-based devices. A pair of inert magnetic discs of different diameters was positioned on the anterior and posterior aspects of the keloid lesion. The magnets were then encapsulated in acrylic resin to improve retention and adaptation, and the external surface was masked with gold glitter to enhance aesthetics and patient acceptance. The helix-deformity case was treated following a complete digital workflow integration where the sound contralateral ear was digitally scanned, mirror-imaged and then 3D-printed in resin to produce an ear model based on which an anatomically symmetrical pressure device was constructed. Results: All devices were successfully fitted and well tolerated, with no reported discomfort or adverse reactions. The wire spring devices were effective in reducing a large keloids volume; however, frequent reactivation every two weeks was required to ensure continuous pressure application. Incorporating magnets in the customised design allowed controlled and uniform pressure application to small keloid-lesion morphology, with enhanced aesthetics and improved patient acceptance and compliance. The digitally assisted case achieved near-perfect anatomical symmetry with the contralateral ear, reducing operator dependency and fabrication guesswork. Conclusions: Customised pressure therapy devices, of magnetic and spring-based systems, alongside utilising digital technologies, offer effective, non-invasive management for auricular keloids and irregular ear helices as long as the patient is committed to wearing the device.

Prosthesis doi: 10.3390/prosthesis8030033

Authors: Reihaneh Ravari Mayank Rehani Justin Lewicke Albert H. Vette Jacqueline S. Hebert

Background/Objectives: Bone-anchored prostheses provide an alternative to socket prostheses, directly connecting the prosthesis to the residual limb via osseointegration. However, limited evidence exists on how spatiotemporal gait parameters and gait symmetry change over time following osseointegration in individuals with unilateral transfemoral amputation. This study aimed to examine changes in spatiotemporal and gait symmetry parameters before osseointegration and at 6 and 12 months post-surgery. Methods: Common spatiotemporal parameters were collected from six individuals with unilateral transfemoral amputation at baseline (with socket prosthesis) and at 6 and 12 months post-osseointegration using a motion analysis system. Group-level differences were assessed using repeated measures ANOVA. Gait symmetry was evaluated using selected spatiotemporal parameters. Results: Following osseointegration, individuals with unilateral transfemoral amputation experienced significant spatiotemporal changes over time. At the group level, walking velocity and stride length decreased at 6 months, with stride length increasing at 12 months. Step width and prosthetic-side step length increased at 12 months relative to 6 months, while intact-side step length decreased. Prosthetic-side toe-off timing was shorter at 12 months. Gait symmetry responses varied individually: some with poor baseline symmetry improved, while those with better baseline symmetry became more asymmetric, indicating heterogeneous outcomes. Conclusions: This study highlights longitudinal changes in gait biomechanics following osseointegration in individuals with unilateral transfemoral amputation. Gait adaptations were highly variable across individuals and time points. Future research should involve larger, more homogeneous samples and incorporate kinetic, muscle activity, and functional outcome measures to better understand the impact of bone-anchored prostheses on gait and mobility.

Prosthesis doi: 10.3390/prosthesis8030032

Authors: Ruihang Zhang Mashrur Muntasir Nuhash A B M Nazmus Salehin Nahid Chayton D. Borman

Heart valve prostheses play a key role in regulating the normal cardiac function for patients with valvular diseases, yet even slight alterations in their flow dynamics can result in serious physiological consequences. This paper provides an overview of in vitro studies using Particle Image Velocimetry (PIV) to investigate the hemodynamics of heart valve prostheses. We first trace the historical evolution of prosthetic valve designs and highlight key milestones in their development. Key experimental considerations for PIV apparatus design are summarized. Subsequently, we review major in vitro PIV studies that have enhanced understanding of prosthetic valve hemodynamics, including flow patterns, turbulence characteristics, and flow–structure interactions. Finally, we outline current challenges and propose future research recommendations, highlighting the potential of integrating advanced PIV methods with high-fidelity imaging for improved assessment of prosthetic valve performances. Overall, the study of heart valve prostheses remains inherently complex due to the multiscale nature of hemodynamic phenomena. Recent advances in experimental fluid mechanics, particularly PIV, have significantly enhanced the ability to visualize and quantify the hemodynamics of prosthetic valves, providing valuable insights for optimizing design and improving the durability of next-generation valve prostheses.

Prosthesis doi: 10.3390/prosthesis8030031

Authors: Lorenzo Moretti Antonio Spinarelli Giuseppe Danilo Cassano Alessandro Scarpino Elvira Ruggiero Alessandro Geronimo Biagio Moretti Giuseppe Solarino

Background/Objectives: Total knee arthroplasty (TKA) is often associated with extensive bleeding and the need for intraoperative and postoperative blood transfusions. Due to concern about the risks associated with them, a push has been made in surgery toward the development of new intraoperative blood management devices and innovative postoperative care strategies. Tranexamic acid (TXA), fibrin sealant and standard electrocautery are widely used in orthopedic surgery, since several studies provided evidence about their efficacy and safety. A new device, the bipolar sealer system (BSS), provides hemostasis at lower temperature (<100°) than conventional electrocautery. It does not produce smoke, necrosis or burn tissue. Methods: In this study, we retrospectively analyzed data from 480 patients who underwent TKA between January 2017 and December 2024. The cohort was divided into two groups based on the hemostatic protocol adopted. The control group enrolled 240 patients who received the standard protocol with TXA and fibrin sealant, while the study group enrolled 240 patients who followed protocol with Aquamantys BSS and TXA. Hematological parameters, including hemoglobin (Hb), hematocrit (HCT) and red blood cells (RBCs) were analyzed preoperatively (T0) and postoperatively: immediately after surgery (T1), at day one (T2) and day three (T3). Results: Changes in hemoglobin from baseline to postoperative follow-up were significantly lower among patients who received TXA plus BSS and those receiving TXA plus fibrin sealant, with p-values of 0.0003 at T1 (immediately after surgery), 0.027 at T2 (one day post-op), and 0.0001 at T3 (three days post-op). Comparable results were observed for HCT and RBC values. Conclusions: These data demonstrate that Aquamantys is more effective than fibrin glue in controlling blood loss after knee replacement surgery, not only immediately after the procedure but also in the following days.

Prosthesis doi: 10.3390/prosthesis8030030

Authors: Mohamed M. Kandil Tamer M. Hamdy Ali Abdelnabi Sahar Ahmed Abdalbary Anas Abed Alkhormani Maha S. Othman

Background: 3D-printed resin composite and hybrid ceramic materials are widely used in prosthetic dentistry for their esthetic, mechanical advantages, and digital compatibility, though their surface properties may be affected by drinking habits. This study aimed to evaluate the influence of a carbonated nutritional beverage multivitamin drink (Oronamin C) on the surface microhardness, roughness, solubility, and color changes in a recently introduced 3D-printed resin composite (Permanent Crown Resin), hybrid ceramic material (Vita Enamic) and a nanohybrid resin composite (Luna). Methods: A total of 120 disk-shaped specimens were distributed according to the type of material into three groups (n = 40). These were divided into four subgroups of specimens for each test (n = 10). The specimens were examined before and after immersion in Oronamin C solution for 12 days. Results: The results showed that there was no significant change in surface microhardness and surface roughness in both 3D-printed resin composite and hybrid ceramic after immersion, while microhardness decreased significantly in the nanohybrid resin composite with an increase in surface roughness. Solubility increased significantly in the nanohybrid and 3D-printed resin composites, but not in the hybrid ceramic. All materials presented clinically acceptable color changes, with mean values lower for both nanohybrid and hybrid ceramic. Conclusions: This study concluded that the hybrid ceramic and 3D-printed resin composite exhibited good stability after Oronamin C beverage exposure, whereas the nanohybrid resin composite exhibited the most impairment among all materials. All materials demonstrated clinically acceptable color changes.

Prosthesis doi: 10.3390/prosthesis8030029

Authors: Larisa Dunai Isabel Seguí Verdú Alba Rey De Viñas Redondo Lilia Sava

Background/Objectives: Hand loss or severe impairment significantly reduces quality of life by restricting essential daily activities and professional tasks. Despite advances in prosthetics, challenges remain in affordability, accessibility, and usability. This study aimed to design and develop a low-cost, ergonomic bionic hand prototype that integrates sustainable fabrication, intuitive control, and modular electronics. Methods: A user-centred design process guided by iterative prototyping, anatomical modelling, and functional validation. The prototype was manufactured using 3D printing techniques and assembled with modular electronic components. The design included segmented fingers, independent thumb articulation, and a tendon-like actuation system driven by micro-motors. Control was implemented through an ESP32-based board and a Bluetooth-enabled mobile application. Durability was preliminarily assessed through 500 grasp–release cycles. Results: Experimental validation confirmed the feasibility of both precision and power grips. The pinch grip successfully lifted objects to 120 g, and the power grip up to 85 g, corresponding to effective output forces of approximately 1.2 N and 0.83 N, respectively. The final prototype weighed ~350 g and maintained reliable performance during 500 grasp–release cycles. Conclusions: The developed bionic hand demonstrates that an affordable, ergonomic, and functional prosthetic can be achieved through sustainable 3D printing and accessible electronics. Future work will focus on enhancing actuation strength, long-term durability, and integration of sensory feedback, with the long-term objective of clinical testing and scalable production.

Prosthesis doi: 10.3390/prosthesis8030028

Authors: Juan Mora-Macías Jorge E. Santos André P. G. Castro Paulo R. Fernandes

Background: Bone tissue engineering has emerged as a promising technique for treating bone defects in large bones. Recent methods have enabled scaffold designs based on predefined microstructures or mechanical behavior patterns, including porosity-graded scaffolds adaptable to heterogeneous load states. However, there is no consensus on the optimal scaffold design strategy, which is sometimes chosen based on the intact bone or results from computational or in vivo experiments. Objective: This work proposes the design of graded-porosity triply periodic minimal surface (TPMS) scaffolds that mimic the mechanical environment within a bone transport callus at the peak of bone tissue production, according to in vivo load measurements. Methods: Finite element models based on computational tomography scans were used to define the strain field of the callus at the peak of bone tissue production. The developed scaffold models were evaluated through finite element simulation. Results: The callus simulations reported that the period in which maximum woven bone tissue production was achieved corresponds to the period of maximum axial strain. The graded-porosity scaffolds simulated demonstrated their ability to replicate this strain field along the callus. The microstructural parameters and strain environment of the proposed graded-porosity scaffolds were consistent with finding from studies assessing the influence of different microstructural parameters or strain conditions on bone ingrown within scaffolds. Conclusions: The proposed approach—designing graded-porosity scaffolds based on the callus strain field at the peak of bone tissue production—proved to be appropriate and may help improve future clinical applications.

Prosthesis doi: 10.3390/prosthesis8030027

Authors: Ricardo Duarte António Ramos

Background/Objectives: Interbody fusion cages provide both structural support and a biologically favorable environment for osseointegration. Through recent decades, cage design and biomaterial selection have evolved to more adapted implants in different concept philosophies. Based on this development, the objective of this work was to develop a systematic review of the state of the art regarding spine interbody cage concepts on the market and anticipate future directions in cage design. Methods: A systematic review following PRISMA 2020 guidelines was conducted in three databases of reference, Scopus, PubMed and Mendeley, in September 2025, considering results from between 2015 and the present using the following keywords: spine, interbody, cage and concept. A revision of the first results was performed, and duplicate entries were excluded, as well as papers without a firm relevance for cage design concepts. Results: This search resulted in 76 selected papers and different design concepts and clinical outputs, and after a duplicate analysis, just 40 papers were selected. The material properties may play an important role in the characteristics of the implant and critically influence load-sharing and bone ingrowth. Surface modifications, including texturing, porosity engineering, and osteoconductive coatings, have been introduced to enhance cellular adhesion and fusion rates. It was observed through the research performed that the main problems are related to micromobility, implant displacement and stress shielding effects in adjacent vertebras. Conclusions: Among the different evolutions observed in cages through the years, design changes played an important role in adapting each case. Knowing that the design could be strongly influenced by the surgical approach used (anterior, posterior, transforaminal or lateral) and bone quality, it is also possible to find, nowadays, different options for different needs that are only accessible due to the technological advances in additive manufacturing, which allowed the development of patient-specific implants.

Prosthesis doi: 10.3390/prosthesis8030026

Authors: Sarah M. Blender Simon Tilsner Luisa Zeh Julia Kowalewski Heike Rudolph Sigmar Schnutenhaus Ralph G. Luthardt

Background/Objectives: The purpose of this study was to investigate the laser removal of implant-supported ceramic single crowns, focusing on their efficiency and the potential reusability of the removed restorations. Methods: Sixty single crowns made of lithium disilicate were adhesively bonded to prefabricated titanium abutments in a total of six test series (n = 10). The test series were divided according to the different spacer settings of the crowns (90 µm, 120 µm, 150 µm) and the taper of the abutments (4°, 6°). After seven days of storage in distilled water, the single crowns were removed using an erbium-doped yttrium aluminium garnet (Er:YAG) laser. The number of laser pulses needed and the time required to remove the crowns were recorded. This was followed by a micro- and macroscopic score evaluation of the crowns using a fluorescent penetration method. Results: Laser removal of all sixty crowns was successfully performed. Using a taper of 6° and a spacer of 150 µm, the crowns were removed with significantly fewer pulses (61.40 (±36.78)). The taper and spacer had a significant effect on both the microscopic (p = 0.040) and macroscopic (p = 0.035) fracture patterns. Based on the final score of the fracture analysis, 44 of the 60 crowns could be classified as potentially reusable. The remaining 16 crowns failed due to purely macroscopic (7), purely microscopic (6), and combined microscopic and macroscopic (3) fracture behavior. Conclusions: Based on the results of this study, increasing the size of the taper and spacer has proven beneficial for laser removal in terms of time efficiency and non-destructive removal of crowns.

Prosthesis doi: 10.3390/prosthesis8030025

Authors: Anuradha Iyer Anand Mathangi Kumar Medhini Madi

Background: The purpose of this systematic review is to understand the epidemiology, risk factors, reporting symptoms, and clinical presentation of denture-induced epulis fissuratum and the various management strategies reported in the literature. Methods: This review was performed in accordance with the PRISMA 2022 guidelines and was registered in the PROSPERO database (CRD42024517759). A systematic electronic search from scientific databases was performed from inception to July 2024. All studies (cross-sectional, observational, and clinical trials), case reports, and case series in the English language addressing the epidemiological and clinical characteristics, as well as the management strategies for prosthetic denture-induced oral epulis fissuratum, were included. The relevant search terms and Boolean operators were employed. Results: A total of 408 articles were obtained from various databases. A total of 41 articles were included for data extraction, of which 20 were case reports and 21 were clinical studies. There were a total of 1472 patients from the included reports. Eighty-two patients had symptomatic epulis fissuratum. A total of 96 patients (6.5%) in the 18 included reports had complete resolution of the lesion following treatment. Conclusions: Diagnosis is primarily based on the pathognomonic clinical presentation of these lesions. Although multiple therapeutic approaches for epulis fissuratum have been described in the literature, a universally accepted or standardized treatment protocol has not yet been established.

Prosthesis doi: 10.3390/prosthesis8030024

Authors: Muralidharan Priyanka Baltha Shreya V. Manju M. P. Hariprasad Prathap Ananth

Background/Objectives: Dental implants are an established modality for oral rehabilitation, but their biomechanical success depends on controlling peri-implant strain, which is influenced by implant angulation, splinting, and length. This in vitro study evaluated the effects of these variables on strain and displacement under axial and oblique loading using digital image correlation (DIC). Methods: Three CBCT-derived mandibular models were 3D-printed and restored with screw-retained full-metal crowns. Group 1 compared parallel vs. angulated implants; Group 2 assessed splinted vs. non-splinted restorations; and Group 3 compared short (4.2 × 6.25 mm) vs. long (4.2 × 13 mm) implants. All specimens were loaded to 500 N at 0°, 15°, and 30° using a universal testing machine. Strain and displacement were analyzed with Istra 4D software and statistically evaluated using ANOVA and independent t-tests (α = 0.05). Results: Parallel implants exhibited progressively higher strain with load angle, peaking at 30° (p < 0.01), while angulated implants recorded their highest strain at 0° (p = 0.008), indicating better adaptation to oblique forces. Splinted restorations significantly reduced strain at 0° and 30° (p = 0.023) and lowered displacement across all inclinations (p = 0.0001). Short implants consistently produced greater strain and displacement than long implants (p < 0.02). Conclusions: Angulated implants mitigated strain under off-axis loading compared to parallel configurations. Splinting decreased strain and displacement, while longer implants consistently improved biomechanical performance. Optimal selection of implant orientation, splinting, and length may minimize peri-implant strain under functional loads. Findings are limited to in vitro conditions with static loading and a single implant system.

Prosthesis doi: 10.3390/prosthesis8030023

Authors: Daniela Garcia Mukul Talaty Maria Flach Alberto Esquenazi

Background/Objectives: Choosing the best prosthetic foot for a patient is complicated by the many available options and limited evidence to distinguish them. This work aimed to clarify performance differences in the level-ground walking of K3-functional-level persons with amputations across a variety of prosthetic feet within the energy storage and return class. Methods: This clinical trial assessed 10 subjects fitted with the Ossur ProFlex foot (LP and XC) compared to their original foot after a 30-day adaptation period and careful prosthetic alignment matching. Multivariate data (walking performance, noise/play, balance and satisfaction) were collected in the gait laboratory. Results: Results were mixed across the cohort. MCID and statistical analysis were used to assess the magnitude and importance of the changes observed. Overall, the changes were small and not statistically significant. Conclusions: Our findings support that performance across a variety of measures for K3-level amputees walking over level ground is relatively insensitive to prosthetic foot componentry within the energy storage and return class. While functional performance is not the only metric that contributes to foot choice, it is an important one. This study helps to circumscribe its role in the larger decision-making framework for this class of componentry in persons with transtibial amputation.

Prosthesis doi: 10.3390/prosthesis8030022

Authors: Elisa Troiano Simone Alongi Cristina Rosa Coco Cristina Latino Tiziano Giacché Stefano Giannotti Nicola Mondanelli

Background/Objectives: The prevalence of joint replacement surgeries has significantly increased over the last century, leading to a corresponding rise in complications, particularly periprosthetic joint infection (PJI). The management of a PJI involves various strategies, including debridement, antibiotic therapy, and staged revision procedures. A notable advancement in treatment is the use of calcium sulfate reabsorbable carriers, recognized for their biocompatibility, osteoconductivity, and localized antibiotic delivery. Recent reports indicate that when combined with conventional treatment regimens, calcium sulfate carriers can achieve infection eradication rates exceeding 90%. This study aims to evaluate the efficacy of calcium sulfate carriers in managing periprosthetic infections, specifically assessing their impact on healing rates in patients undergoing treatment. Study Design & Methods: A retrospective analysis was conducted at our institution, focusing on patients diagnosed with PJIs treated with 2-stage revision surgery with local application of calcium sulfate carriers with antibiotics at both stages, and systemic antibiotic therapy, and comparing results with different surgical procedures. Results: The study included 40 patients (24 males and 16 females), with a mean age of 68.7 (range 48–87) years. The affected joints included the hip (27.5%), shoulder (27.5%), and knee (45%). The findings revealed that 97% of patients achieved infection eradication at the end of the follow-up period. Conclusions: These results highlight the complexities of managing PJIs and the significant role of calcium sulfate carriers in improving outcomes, supporting their use as a standard practice in confirmed PJI cases.

Prosthesis doi: 10.3390/prosthesis8020021

Authors: Arunee Promsri

Background: Transtibial prostheses are commonly classified as endoskeletal or exoskeletal and differ in weight, adaptability, and mechanical response, which may influence gait performance. This study examined whether prosthesis type affects overground walking movement structure and neuromuscular control and assessed the relationship between walking speed and neuromuscular control. Methods: Principal component analysis (PCA) was applied to kinematic marker data from 20 unilateral transtibial amputees using either endoskeletal (n = 10; 54.7 ± 6.1 years) or exoskeletal prostheses (n = 10; 57.9 ± 8.7 years) during self-selected overground walking. Principal movements (PMs) were extracted to represent functionally meaningful gait components. Movement structure was evaluated using the relative explained variance of PM positions (rVAR), whereas neuromuscular control was quantified using the root mean square of PM accelerations (RMS; acceleration magnitude) and the number of zero crossings (N; regularity/predictability). Group differences were examined using covariate-adjusted analyses, controlling for preferred walking speed. Results: No significant differences in walking movement structure were found between prosthetic types. Unadjusted analyses suggested greater swing-phase acceleration (PM2) and lower neuromuscular variability across PM1–PM4 in the endoskeletal group; however, these effects were no longer significant after adjusting for BMI and walking speed. Walking speed showed strong associations with neuromuscular control (p ≤ 0.003), with faster speeds linked to greater swing-phase acceleration and reduced variability. Conclusions: Walking movement structure and neuromuscular control were comparable between prosthetic types, while walking speed emerged as a key factor in gait evaluation among transtibial amputees.

Prosthesis doi: 10.3390/prosthesis8020020

Authors: Koji Naito Akiyoshi Funato Tsutomu Tanno Keisuke Seki

In implant treatment in the aesthetic zone, high aesthetic quality is required in addition to functionality and long-term stability when reconstructing defects in peri-implant tissues. Post-traumatic cases often present with extensive loss of both hard and soft tissues, making the selection of an appropriate grafting method essential. This report describes a case in which an interpositional gingival graft (IGG) and a strip gingival graft (SGG) were combined to regenerate peri-implant soft tissue following guided bone regeneration (GBR), maintaining favorable tissue morphology and aesthetics for six years. The patient was a 53-year-old woman who suffered trauma after falling down stairs, resulting in a fractured bridge in the right maxillary canine region and crown fracture. The traumatized tooth was extracted, and GBR was performed to restore hard tissue volume. Subsequently, IGG and SGG were used to improve soft tissue thickness, interproximal papilla height, and a healthy mucogingival junction (MGJ). A cantilever implant prosthesis was selected as the final restoration. Over six years, no gingival recession or marginal bone loss was observed, and excellent aesthetic stability was maintained. A mini-review of published reports on IGG and SGG demonstrated their efficacy in enhancing soft tissue volume. The findings of this case suggest that a comprehensive approach—including bone augmentation, soft tissue grafting, and prosthetic design—can provide predictable, long-term aesthetic and functional outcomes in complex post-traumatic cases (223).

Prosthesis doi: 10.3390/prosthesis8020019

Authors: Gabrielle Beatrice Cui Batiller Yeuk Ying Wong Akhila Pudipeddi Tong Wah Lim

Objective: This study aimed to quantitatively evaluate five opportunistic respiratory pathogens among individuals, with or without dentures, who have either healthy or diseased periodontal conditions. Methods: Saliva samples were obtained from 24 older adults. DNA extraction was performed, followed by a quantitative Polymerase Chain Reaction targeting five opportunistic respiratory pathogens, namely Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes, Klebsiella pneumoniae, and Streptococcus agalactiae. The abundance of opportunistic pathogens among the four groups [denture-wearing with active periodontal disease (DAP), non-denture-wearing with active periodontal disease (NDAP), denture-wearing with stable periodontal health (DSP), and non-denture-wearing with stable periodontal health (NDSP)] were compared. Results: Saliva samples of all participants (100%) carried at least one opportunistic respiratory pathogen. Of the five pathogens, S. aureus, P. aeruginosa, K. pneumoniae, and S. agalactiae were present in more than 50% of the samples. A significant difference in the bacterial load of K. pneumoniae and P. aeruginosa was observed (p < 0.05). The quantity of P. aeruginosa in the NDAP group was significantly lower than the DSP group. However, for K. pneumoniae, no significant differences between the groups were detected. Conclusions: In this small pilot cohort, a relatively high prevalence and substantial microbial load of opportunistic respiratory pathogens were identified in the saliva of older adults. On the basis of these preliminary findings, optimal oral and denture hygiene care is suggested as a potential approach to reduce the presence and burden of respiratory pathogens in this population, although larger studies are required to confirm these associations and determine their clinical significance.

Prosthesis doi: 10.3390/prosthesis8020018

Authors: Marco Tallarico Francesco Grande Gianluca Fortunato Carlotta Cacciò Soo-young Lee Young-jin Cho Kwan-tae Noh Chikahiro Ohkubo Felipe Aguirre Recep Uzgur Gaetano Noè Santo Catapano Gabriele Cervino

Aim: To develop clear, evidence-based, and standardized guidelines for the design, selection, and clinical use of implant abutments and prosthetic components in order to optimize the biological, mechanical, and esthetic performance of the implant supracrestal complex. Methods: A panel of 10 expert clinicians and researchers in prosthodontics participated in the Osstem Global Consensus Meeting. For the present consensus meeting, a scoping review was performed in advance and discussed among the participants. A comprehensive search of the literature was performed up to June 2025. Two reviewers (M.T. and F.G.) independently conducted screening, data extraction, and quality assessment using the Newcastle–Ottawa Scale. The evidence was synthesized and discussed by the panel of expert clinicians during the consensus meeting. After that, guidelines were developed using a 14-question questionnaire to formulate consensus-based clinical recommendations. The participants answered structured questions and discussed discrepancies to achieve a consensus. Results: The panel of expert clinicians reached a consensus on several prosthetic key points. Concave abutment profiles and emergence angles <30° promoted peri-implant tissue stability, while convex designs and wider angles increased risks of bone loss and peri-implantitis. Titanium remains the reference abutment material in posterior sites, while zirconia provides superior esthetics anteriorly, and hybrid abutments balance strength and esthetics. Conclusions: Prosthetic design and abutment material selection critically affect peri-implant tissue stability and esthetic outcomes. The evidence supports screw-retained designs, platform switching, and the “one abutment–one time” approach for predictable long-term success.

Prosthesis doi: 10.3390/prosthesis8020017

Authors: Mohanned M. Toras Ossama Raffa Hanaa Ashkar Faris Alsufi Loai Alsofi

This case report describes the esthetic and functional rehabilitation of a 45-year-old male patient presenting with a missing maxillary right lateral incisor (#12). Due to persistent insufficiency of alveolar ridge width following multiple augmentation procedures, implant placement was contraindicated. A minimally invasive prosthetic approach was therefore selected, consisting of a single-retainer lithium disilicate resin-bonded fixed dental prosthesis (RBFDP) combined with laminate veneers to optimize anterior esthetics. The cantilever design and adhesive protocol were selected based on biomechanical principles aimed at minimizing interfacial stresses and preserving enamel structure. The prosthesis was fabricated using a fully digital workflow, and adhesive bonding was performed following established ceramic and enamel surface conditioning protocols. The restoration fulfilled the patient’s esthetic and functional expectations, and clinical follow-up at 18 months demonstrated stable bonding, healthy peri-abutment tissues, and absence of technical or biological complications. This case highlights the role of lithium disilicate cantilever RBFDPs as a minimally invasive and clinically viable treatment option for the replacement of maxillary lateral incisors when implant therapy is contraindicated, with outcomes limited to short- to medium-term observation.

Prosthesis doi: 10.3390/prosthesis8020016

Authors: Ryota Sayama Yukio Agarie Hironori Suda Hiroshi Otsuka Kengo Ohnishi Shinichiro Kon Akihiko Hanahusa Motoki Takagi Shinichiro Yamamoto

Background: Accurate evaluation of pressure distribution at the socket–limb interface is essential for improving prosthetic fit and comfort in transfemoral amputees. This study aimed to develop a proof-of-concept framework that integrates machine learning–based segmentation with the finite element method (FEM) to explore the feasibility of an initial workflow for residual-limb analysis during socket application. Methods: MRI data from a transfemoral amputee were processed using a custom image segmentation algorithm to extract adipose tissue, femur, and ischium, achieving high F-measure scores. The segmented tissues were reconstructed into 3D models, refined through outlier removal and surface smoothing, and used for FEM simulations in LS-DYNA. Pressure values were extracted at nine sensor locations and compared with experimental measurements to provide a preliminary qualitative assessment of model behaviour. Results: The results showed consistent polarity between measured and simulated values across all points. Moderate correspondence was observed at eight low-pressure locations, whereas a substantial discrepancy occurred at the ischial tuberosity (IS), the primary load-bearing site. This discrepancy likely reflects the combined influence of geometric deviation in the reconstructed ischium and the non-physiological medial boundary condition required to prevent unrealistic tissue displacement. This limitation indicates that the current formulation does not support reliable quantitative interpretation at clinically critical locations. Conclusions: Overall, the proposed framework provides an initial demonstration of the methodological feasibility of combining automated anatomical modeling with FEM for exploratory pressure evaluation, indicating that such an integrated pipeline may serve as a useful foundation for future development. While extensive refinement and validation are required before any quantitative or clinically meaningful application is possible, this work represents an early step toward more advanced computational investigations of transfemoral socket–limb interaction.

Prosthesis doi: 10.3390/prosthesis8020015

Authors: Gunther Felmerer Edward de Keating-Hart Jérôme Pierrart Claire Bonamici Guillaume Bokobza Marta Da Costa Silvio Bagnarosa Alperen Sabri Bingoel Daniela Wüstefeld Erik Andres Wolfgang Lehmann Jonathan Frederic Götz

Background: Targeted muscle reinnervation (TMR) is increasingly used to enhance prosthetic control and to reduce post-amputation pain. Its implementation across new centers raises questions about the reproducibility of outcomes and the impact of surgical experience. Methods: We compared the first three TMR patients treated in a newly established center in Nantes, France, with three patients treated in a high-volume center in Göttingen, Germany. Functional outcomes were measured using the Box and Block test (BBT), and operative time was recorded. Two French cases were performed with the assistance of a Göttingen-based surgeon. Conclusions: The functional outcomes showed a similar trend in both groups. The mean BBT scores were equivalent, suggesting reliable reinnervation and prosthetic integration even in early cases. Operative times were longer in Nantes, but did not impact outcomes. TMR appears not to have a pronounced learning curve, particularly regarding functional success in early cases under guided protocols. Factors such as assistance from experienced surgeons and favorable donor-to-recipient nerve ratios likely contribute to consistent outcomes. These findings support the reproducibility of TMR across institutions. Results: Within the first two years of rehabilitation we observed improvements in both functional performance and patient-reported quality of life. All six patients across both centers in-creased in BBT scores. All the patients reported an increase in social relationships and psychological health, and two of three patients reported an increase in physical health. Importantly, all six patients discontinued the use of pain medication at 2 years fol-lowing TMR. Furthermore, the French patients reported a decrease from 65–82 mm to 0–31 mm across the patients’ Visual Analog Scale (VAS) pain scores.

Prosthesis doi: 10.3390/prosthesis8020014

Authors: Szidonia Krisztina Veress Bálint Botond Bögözi Lajos Csönge Bernadette Kerekes-Máthé Melinda Székely

Background/Objectives: Bone grafting is fundamental in oral implantology in order to achieve appropriate esthetic and functional results. One of the options for bone grafting is the use of allografts, which can be produced using femoral heads removed during orthopedic surgeries in accordance with the principles of the circular economy. The aim of this study is to examine the environmental impacts of the production of cancellous block and granulates of bone graft materials produced in this way. Methods: The cradle-to-gate life cycle assessment was performed at the Petz Aladár University Teaching Hospital Tissue Bank Department, Győr, Hungary, with the system boundaries defined and the bone graft material produced during a production process defined as a functional unit. The environmental impacts were determined with the OpenLCA v2.5.0. software, using the ReCiPe v1.03 2016 midpoint (H) and endpoint (H) assessment methods. Results: During the production process, 500 g of bone graft material is produced in both forms, packaged as 1 g. The carbon footprint of the production of the cancellous bone block was 88,972 kgCO2-Eq, while that of the bone granulates was 100,033 kgCO2-Eq, to which the chemicals used for the degreasing and deantigenization of the bone tissue contributed the most. Within the impact categories, the material resources of metals–minerals, terrestrial ecotoxicity and climate change contributed the most to the environmental impacts. Within most impact categories, electricity was the most significant influencing factor. Conclusions: The environmental impact of the production of bone substitute granulates is greater than that of the bone block, to which the packaging of the products contributes primarily.

Prosthesis doi: 10.3390/prosthesis8020013

Authors: Miguel de Araújo Nobre Armando Lopes Carolina Antunes Francisco Salvado

Background/Objectives: Implant-supported rehabilitations using the All-on-4 concept represent a viable treatment option for completely edentulous patients. The guided surgery software allows for the performance of a flapless computer-guided surgery with similar results to those achieved through a flap surgery. This study aimed to evaluate the long-term outcomes of complete edentulous implant-supported rehabilitations using an All-on-4 arrangement, following a computer-guided protocol. Methods: A total of 111 patients (68 females, 43 males) with an average age of 60.9 years ± 9.67 years were treated. The primary outcome measures were implant and prosthetic survival. Secondary outcome measures were marginal bone loss (MBL) and the incidence of mechanical and biological complications. Results: Thirty-nine patients were lost to follow-up. Thirty-seven implants and five prostheses failed, rendering a 92.5% implant cumulative survival rate and a 96.2% prosthetic survival rate at 12 years. The average MBL per implant was 1.19 ± 1.16 mm, with 1.26 ± 1.33 mm for axial implants and 1.12 ± 0.95 mm for tilted implants at 10 years. The incidence rate of mechanical complications at the patient level was 90.1% for provisional prostheses and 55.9% for definitive prostheses. The rate of biological complications was 14.3% at the implant level. Conclusions: Full-arch rehabilitations following an All-on-4 implant arrangement and assisted by a computer-guided protocol may be a viable alternative for patients with edentulism/hopeless teeth in the long term.

Prosthesis doi: 10.3390/prosthesis8010012

Authors: Mashael Binhasan Sadeem Alkhamees Reem Alkhraiyef Shahad Alsumikhi Sara Shabib Nourah Shono Haifa Barakah Nassr Al-Maflehi

Objectives: This study investigated the effects of three over-the-counter (OTC) whitening products, whitening pen (WP, Dazzling White Instant Whitening Pen, Dazzling White, Grand Rapids, MI, USA), whitening mouthwash (MW, Colgate Optic White, Colgate-Palmolive, New York, NY, USA), and whitening toothpaste (TP, Crest 3D White, Procter & Gamble, Cincinnati, OH, USA), on the microhardness, gloss retention, and surface roughness of a nanofilled resin composite (Filtek Z350 XT Universal Restorative, 3M ESPE). Methods: Composite resin specimens were prepared and subjected to treatment with WP, MW, or TP. Microhardness, gloss retention, and surface roughness were measured before and after treatment. Data were subjected to statistical analysis, with normality assessed by Shapiro–Wilk testing. Parametric data were summarized as mean ± SD, and differences were evaluated using paired t-tests and one-way ANOVA with a significance level of p ≤ 0. 05. Results: All whitening products significantly altered the tested surface properties. Microhardness decreased in all groups (MD [95% CI]: 2.28 [1.84–2.71] for WP, 5.05 [4.22–5.88] for MW, and 3.09 [2.35–3.83] for TP; p < 0.001), with the greatest reduction observed in the MW group. Gloss retention also declined significantly (MD [95% CI]: 9.52 [6.28–12.76] for WP, 17.97 [14.92–21.01] for MW, and 18.92 [15.64–22.21] for TP; p < 0.001), with TP and MW showing greater loss compared to WP. Surface roughness increased significantly within each group (MD [95% CI]: −0.07 [–0.10 to −0.04] for WP, −0.23 [–0.30 to −0.16] for MW, and −0.25 [–0.38 to −0.13] for TP; p < 0.001), although no significant differences were found among groups in post-treatment values. Conclusions: OTC whitening products adversely affected the optical and mechanical properties of Z350 XT universal composite resin. Whitening MW caused the most pronounced microhardness reduction, while MW and TP induced greater gloss loss than WP. Clinicians should consider the potential impact of whitening products on resin composite restorations when advising patients on their use.

Prosthesis doi: 10.3390/prosthesis8010011

Authors: Ihab Nabeel Safi Hasanain K. A. Alalwan Mustafa S. Tukmachi Dhuha H. Mohammed Maryam Sinan Abdulaali Al-Yasari

Background/Objectives: The use of zirconia implants is gaining traction as a potential alternative to titanium. Although having excellent properties, the zirconia surface has limited osteogenic potential. The purpose of this study was to produce, for the first time, mechanically stable, thick micron-scale hydroxyapatite coatings on zirconia implant material using radiofrequency (RF) magnetron sputtering. Methods: Zirconia samples were coated with HA using an RF magnetron sputtering device at a temperature of 125 °C for 20 h with 155 W of power. The procedure included rotating the substrate at a speed of 10 rpm while an argon gas flow was maintained continuously. Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) analysis, atomic force microscopy, and Vickers hardness measurements were used to evaluate the coat’s characteristics. Results: A smooth hydroxyapatite coating layer that was consistent and free of cracks was observed in all FESEM pictures. The EDX study revealed that the substrate surface contains HA particles, and the ratio of calcium (Ca) to phosphorus (P) was 16.58 to 11.31, which is very close to the ratio in original HA. FESEM cross-section pictures showed good adhesion between the coating and substrate without any gaps, and the coating thickness was 5 µm on average. A statistically significant difference was found in the roughness analysis between the samples of uncoated Zr and HA-coated Zr (p-value < 0.05). Conclusions: Zirconia implant material can be coated with a uniform layer of HA, displaying good adhesion and a thickness of a few micrometers when using magnetron sputtering for an extended period of time.

Prosthesis doi: 10.3390/prosthesis8010010

Authors: Ketsupha Suwanarpa Yoko Hasegawa Jarin Paphangkorakit Atthasit Kanwiwatthanakun Kazuhiro Hori Takahiro Ono

Background/Objectives: Oral function impairment negatively impacts nutrition, health, and quality of life in older adults. While retaining ≥20 natural teeth is often recommended for maintaining oral function, its validity is uncertain, particularly for those who adapt to tooth loss with dentures. This study aimed to determine the minimum number of remaining functional teeth necessary to prevent oral hypofunction in older adults, focusing on two diagnostic criteria: decreased masticatory function and reduced occlusal force. Methods: A total of 154 participants (≥60 years) were included. Oral examination assessed the number of remaining functional teeth. To assess masticatory function, masticatory performance was objectively measured using a visual scoring method of gummy jelly, and occlusal force was quantified with pressure-sensitive film. Pearson’s correlation analyzed relationships among variables, while receiver operating characteristic (ROC) analysis identified optimal tooth number cut-offs for detecting decreased masticatory function (score ≤ 2) and reduced occlusal force (<500 N). Results: Significant positive correlations were found between the number of remaining functional teeth and both masticatory performance (r = 0.591, p < 0.001) and occlusal force (r = 0.453, p < 0.001). ROC indicated that 17 teeth was the optimal threshold for identifying both decreased masticatory performance and reduced occlusal force, with sensitivities of 0.79 and 0.72 and specificities of 0.93 and 0.88, respectively. Conclusions: Retention of 17 or more remaining functional teeth may be sufficient to maintain adequate masticatory performance and occlusal force. These findings serves as a preliminary guide for treatment planning and targeted interventions focused on preserving tooth retention and improving oral function in aging populations.

Prosthesis doi: 10.3390/prosthesis8010009

Authors: Forbes Kent Amelinda Putri Yosica Mariana Intan Mahardika Christian Harito Grasheli Kusuma Andhini Cokisela Christian Lumban Tobing

Background/Objectives: An individual with a hand disability, whether caused by an accident, disease, or congenital condition, may have significant problems with their daily activities, self-perception, and ability to work. Prosthetic hands can be used to restore essential hand functions, and features such as adaptive grasps can enhance their usability. Due to noise in the sEMG signal and hardware limitations in the system, reliable myoelectric control remains a challenge for low-cost prosthetics. ESP32 microcontrollers are used in this study to develop an SVM-based sEMG classifier that addresses these issues and improves responsiveness and accuracy. A 3D-printed mechanical structure supports the prosthesis, reducing production costs and making it more accessible. Methods: The prosthetic hand is developed using an ESP32 as the microcontroller, a Myoware Muscle Sensor to detect muscle activity, and an ESP32-based control system that integrates sEMG acquisition, SVM classification, and finger actuation with FSR feedback. A surface electromyography (sEMG) method is paired with a Support Vector Machine (SVM) algorithm to help classify signals from the sensor to improve the user’s experience and finger adaptability. Results: The SVM classifier achieved 89.10% accuracy, an F1-score of 0.89, and an AUC of 0.92, with real-time testing demonstrating that the ESP32 could reliably distinguish flexion and extension signals and actuate the servo, accordingly, producing movements consistent with the kinematic simulations. Complementing this control performance, the prosthetic hand was constructed using a coupled 4 bar linkage mechanism fabricated in PLA+, selected for its superior factor of safety compared to the other tested materials, ensuring sufficient structural reliability during operation. Conclusions: The results demonstrate that SVM-based sEMG classification can be effectively implemented on low-power microcontrollers for intuitive, low-cost prosthetic control. Further work is needed to expand beyond two-class detection and increase robustness against muscle fatigue and sensor placement variability.

Prosthesis doi: 10.3390/prosthesis8010008

Authors: Alexandra Ecaterina Saveanu Catalina Iulia Saveanu Oana Dragos Maria Sophia Saveanu Daniela Anistoroaei

Background: Resin infiltration has emerged as a micro-invasive strategy for managing enamel porosities, offering both therapeutic and aesthetic benefits. ICON® (DMG, Hamburg, Germany) is the most widely used system; however, evidence on its penetration behavior in sound enamel remains limited. Objectives: This in vitro study aimed to evaluate the penetration depth and morphological pattern of ICON resin infiltration in sound human enamel, using quantitative morphometric analysis and scanning electron microscopy (SEM). Methods: Fourteen freshly extracted, caries-free anterior teeth were sectioned longitudinally. ICON® resin infiltrate was applied to the buccal enamel surfaces according to the manufacturer’s protocol, while the lingual/palatal surfaces served as internal controls. Penetration depth was measured quantitatively on both mesial (surface A) and distal (surface B) halves, and SEM was used to assess resin–enamel interface morphology. Statistical analysis included the Shapiro–Wilk test, paired t-test, Pearson correlation, and percentage difference calculation. Results: The mean difference in penetration depth between surfaces A and B was −21.29 µm (p = 0.525), indicating no statistically significant variation. A strong positive correlation was observed between surfaces (r = 0.783, p = 0.001). The mean percentage difference was −3.57% (SD = 18.61%), suggesting minimal directional bias. SEM images confirmed continuous and homogeneous resin infiltration within enamel prisms. Post-hoc power analysis indicated 15.2% power, reflecting the impact of the limited sample size typical for SEM-based exploratory studies. Conclusions: Within the limitations of this in vitro investigation, ICON resin infiltration demonstrated uniform and consistent penetration in sound enamel, supported by both quantitative and SEM analyses. These findings validate its potential as a reliable preventive and micro-invasive biomaterial in dental practice, particularly for protecting enamel surfaces prior to orthodontic bracket bonding. Further clinical research with larger cohorts is recommended to confirm its long-term stability and prophylactic performance.

Prosthesis doi: 10.3390/prosthesis8010007

Authors: Iñigo De La Joya Jhonatan da Ponte Lopes Jeroen H. M. Bergmann

Upper limb deficiencies can limit the range of tasks children can perform. Current prosthetics provide overall good performance to increase the activities that users can complete, but challenges remain. Body- or electrically powered prostheses struggle to restore the full range of motion needed for specific tasks. Currently, these systems do not allow for controlled hand closure or opening across all possible postures. A breathing-powered prototype named Airbender, which extracts energy from a breathing input by means of a Tesla turbine, provides the possibility of operation in any position. This paper introduces a novel design for a multi-finger actuated breathing-powered upper limb prosthetic concept and analyses its performance through a series of lab-based experiments. Results show that such a design could provide a fully controllable system. The final assembled design is capable of achieving full actuation under a flow rate of 340 Ls/min. The results obtained demonstrate that a functional multi-finger actuated breathing-powered upper limb prosthesis could be feasible and opens a path for future research in the field, with the ultimate goal of reducing the minimum flow rate required and actuation time to further improve its functionality.

Prosthesis doi: 10.3390/prosthesis8010006

Authors: Armando Crupi Giancarlo Pecorari Vincenzo Ronsivalle Marco Cicciù

Background: Rehabilitation of head and neck cancer patients with acquired intraoral defects is challenging and requires multidisciplinary collaboration. This case report describes an integrated surgical and prosthetic approach in which palatal obturator rehabilitation is used to restore palatal integrity, speech, swallowing, aesthetics, and overall quality of life after maxillectomy. The objective is to show how careful surgical planning to optimize prosthetic prognosis, combined with a precisely designed obturator prosthesis, can achieve satisfactory functional rehabilitation. Methods: A man in his 50s with sinonasal carcinoma underwent partial left maxillectomy followed by radiotherapy and chemotherapy. The defect was classified as Aramany class I and Brown class 2b, and the surgical resection was planned to preserve structures favorable to prosthetic support. Prosthetic management included fabrication of a removable partial denture incorporating a hollow-bulb obturator. Results: During trial and delivery, the patient demonstrated improved speech and swallowing, enhanced denture stability, and favorable aesthetics. The patient reported satisfaction with functional and cosmetic outcomes and was provided with instructions for use and cleaning, with a plan for regular follow-up. Conclusions: Palatal obturator prostheses remain a gold standard for unilateral maxillectomy rehabilitation when adequate retention is achievable. Surgical-prosthetic collaboration permits restoring palatal contours, and dentition can normalize speech and swallowing, and substantially improve the quality of life.

Prosthesis doi: 10.3390/prosthesis8010005

Authors: Isabelle Loiret Clément Duraffourg Iris Permentiers Pascal Barbazanges Guillaume Bokobza Marta Da Costa Estelle Elie Nicolas Fons Christophe Popineau Sandrine Rey Ghislaine Roche Yoann Ronzi Marie Thomas-Pohl Rémi Klotz Laurine Calistri

Background: Various socket designs exist, linking the residual limb together with the prosthetic components to restore the ability to walk; however, lack of socket comfort is a frequent complaint. Objective: To evaluate the impact of socket design on end-user comfort and mobility. Methods: A randomized crossover trial was set to compare comfort and mobility of above-knee amputees (AKAs) wearing an ischial containment (IC) or subischial (I-SUB) socket. Patients actively wearing IC sockets were recruited from 10 rehabilitation centers across the country. They were then fitted for an I-SUB socket by Certified Prosthetists (CPs) as an alternate socket. Participants were randomly assigned to start with one or the other socket. After a minimum of 2 weeks, each participant evaluated the Socket Comfort Score (SCS) (primary outcome) in various situations, performed the 2-min walk test, and answered the PLUS-M questionnaire (secondary outcomes). Results: A total of 25 participants were included, of whom 23 completed the study with full (n = 21) or partial data (n = 2). SCS were improved with I-SUB compared with IC in all situations, with significant differences in general, when sitting on a rigid chair, sitting in a car, and standing. The differences in self-reported mobility and walking distance at the 2-min walk test were not significant. At the end of the study, more than 80% of the participants chose to keep the I-SUB socket for their daily use. Conclusions: For the first time, this study supports that the subischial suction socket improves comfort in daily life without negatively impacting user mobility in a group of individuals with AKA.

Prosthesis doi: 10.3390/prosthesis8010004

Authors: Mariano Fernández-Fairén Luis M. Delgado Matilde Roquette Javier Gil

Background: Postoperative infections remain a major complication in spinal surgeries involving intersomatic screws, often compromising osseointegration and long-term implant stability. Questions/Purposes: This study evaluated a nanotextured titanium oxide surface with nanopillar-like morphology designed to reduce bacterial colonization while preserving mechanical integrity and promoting bone integration. Methods: Ti6Al4V screws were studied in three batches: control, passivated with HCl and acid mixture treatment to obtain nanotopographies on the surfaces. To create the nanotopographies, the screws were treated with a 1:1 (v/v) sulfuric acid–hydrogen peroxide solution for 2 h. Surface morphology, roughness, wettability, and surface energy were analyzed by SEM, confocal microscopy, and contact angle measurements. Corrosion and ion release were assessed electrochemically and by ICP-MS, respectively. Mechanical behavior, cytocompatibility, mineralization, and antibacterial efficacy were evaluated in vitro. Osseointegration was analyzed in rabbit tibiae after 21 days by histology and bone–implant contact (BIC). Results: The treatment produced uniform nanopillars (Ra = 0.12 µm) with increased hydrophilicity (49° vs. 102° control) and higher surface energy. Mechanical properties and fatigue resistance (~600 N, 10 million cycles) were unaffected. Corrosion currents and Ti ion release remained low. Nanopillar surfaces enhanced osteoblast adhesion and mineralization and reduced bacterial viability by >60% for most strains. In vivo, Bone Index Contact (BIC) was higher for nanopillars (52.0%) than for HCl-treated (43.8%) and control (40.1%) screws, showing a positive osseointegration trend (p > 0.005). Conclusions: The proposed acid-etching process generates a stable, scalable nanotopography with promising antibacterial and osteogenic potential while maintaining the alloy’s mechanical and chemical integrity. Clinical relevance: This simple, scalable, and drug-free surface modification offers a promising approach to reduce postoperative infections and promote bone integration in spinal implants.

Prosthesis doi: 10.3390/prosthesis8010003

Authors: Soz Grundig Kawan Othman Bruska Azhdar

Background/Objectives: This in vitro study examined the potential enhancement in resistance to accelerated aging in room-temperature vulcanized (RTV) maxillofacial silicone, intrinsically pigmented in two skin tones, through the use of zirconium oxide (ZrO2) nanoparticles. Methods: A total of 128 disc-shaped specimens were created in rose silk and soft brown shades, each containing zirconium oxide concentrations of 0%, 1%, 2%, and 3% by weight. Color variation (ΔE*) was assessed initially and following 252, 750, and 1252 h of artificial aging, tested with a colorimeter. Surface roughness characteristics (Ra, Rq, Rt) were evaluated before and after 1252 h using atomic force microscopy (AFM). Structural, vibrational, and morphological characteristics were analyzed through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM). Results: Non-parametric tests (Friedman, Kruskal–Wallis, and Bonferroni-adjusted paired testing; p < 0.05) indicated that accelerated aging significantly increased ΔE* in all specimens. The addition of ZrO2 reduced these changes; however, the optimal concentration differed by pigment: 1% for rose silk and 3% for soft brown. The effect on surface roughness depended on pigment type. Higher nanoparticle concentrations generally improved post-aging smoothness in soft brown samples, whereas rose silk showed a more variable response. XRD and FTIR analyses confirmed successful nanoparticle incorporation without altering the fundamental silicone structure, while FESEM demonstrated improved filler–matrix interaction in modified groups. Conclusions: Adjusting ZrO2 concentration according to pigment type can improve the future color retention and surface characteristics of maxillofacial silicone.

Prosthesis doi: 10.3390/prosthesis8010002

Authors: Valentin Lamasanu Dragos Ioan Virvescu Ionut Luchian Gabriel Rotundu Oana-Maria Butnaru Dana Gabriela Budala Florin Razvan Curca Florinel Cosmin Bida Carina Balcos Zinovia Surlari Monica Silvia Tatarciuc

Background/Objectives: The rapid evolution of digital technologies has significantly transformed prosthodontic workflows, improving clinical precision, communication, and patient satisfaction. However, the extent to which dental professionals perceive, integrate, and evaluate these technologies remains insufficiently standardized. This study aimed to develop and validate a questionnaire for assessing perceptions, attitudes, perceived advantages, barriers, and future intentions regarding the use of digital technologies in prosthodontic practice. Methods: A cross-sectional survey was conducted among 420 dental professionals (305 dentists and 115 dental technicians) from Northeastern Romania. The 27-item questionnaire, structured on five theoretical dimensions, was distributed online via the Survio platform. Internal consistency was assessed using Cronbach’s Alpha, and construct validity was analyzed through Exploratory Factor Analysis (Principal Component Analysis with Varimax rotation). Conclusions: Cronbach’s Alpha coefficients ranged from 0.700 to 0.799 across the five dimensions, indicating acceptable to very good internal reliability. The Kaiser–Meyer–Olkin value (0.646) and Bartlett’s Test of Sphericity (p < 0.001) confirmed data suitability for factor analysis. The validated questionnaire represents a reliable and conceptually coherent tool for evaluating professional perspectives on digitalization in prosthodontics. Its application can inform educational strategies, guide institutional investments, and support a balanced transition toward integrated digital workflows in clinical and laboratory settings.

Prosthesis doi: 10.3390/prosthesis8010001

Authors: Reem W. Massarweh Mohammad M. D. Sobuh

Background/Objectives: Amputation often leads to decreased body image satisfaction and self-acceptance, affecting mental health and social integration. The Amputee Body Image Scale (ABIS) is a validated tool designed to assess satisfaction and measure body image acceptance. The scale has been translated into many languages to improve rehabilitation services for individuals with amputation worldwide; however, a validated Arabic version of this scale does not currently exist. The study aims to cross-culturally adapt and validate the ABIS for Arabic-speaking individuals with lower-limb amputation. Methods: A cross-cultural adaptation was performed according to the International Test Commission (ITC) guidelines. The adapted Arabic version of the scale was completed by 100 Jordanian individuals with lower-limb amputations. Their responses were then statistically analyzed using factor analysis to assess content and construct validity and Cronbach’s α to assess internal consistency (reliability). Results: The Arabic version of the ABIS demonstrated strong construct validity (KMO = 0.898; Bartlett’s test p < 0.001) and high internal consistency (Cronbach’s alpha = 0.92), while factor analysis suggested the multidimensionality of the scale after cross-cultural adaptation. Conclusions: The findings suggest the preliminary validity and reliability of the Arabic version of the ABIS, supporting its potential use in rehabilitation centres to assess body image satisfaction among Arabic-speaking individuals with amputation. Nevertheless, further improvements are warranted to adapt the scale to Arabic culture.

Prosthesis doi: 10.3390/prosthesis7060169

Authors: Saverio Ceraulo Antonio Barbarisi Zhong Hao Hu Gianluigi Caccianiga Dorina Lauritano Francesco Carinci

Background: Nylon-based removable partial dentures, such as Valplast® (Valplast International Corp, Westbury NY, USA), have been proposed as a valuable alternative to acrylic resin prostheses, particularly following oral surgical extractions and in patients with suspected methacrylate hypersensitivity. This review aimed to evaluate the clinical indications guiding the use of nylon-based prostheses after oral surgical extractions and to investigate their prevalence in patients with documented acrylic allergies. Methods: Following PRISMA 2020 guidelines, a comprehensive search was conducted in six databases (PubMed, Scopus, Embase, Google Scholar, LILACS, and Cochrane Library) for studies published between 2015 and 2025. Eligible studies were critically appraised using the Joanna Briggs Institute (IBI) tools. Results: Nine studies met the inclusion criteria, all of which were low-level evidence (six case reports and three case series), comprising a total of 11 patients (mean age 43 years). Nylon-based prostheses were used in both maxillary and mandibular arches, with rehabilitation motivated by esthetic and functional reasons. Outcomes were generally favorable, with patients reporting satisfaction in terms of comfort, function, and esthetics. Conclusions: Current evidence supporting the use of nylon-based removable partial dentures remains extremely limited and is based exclusively on case reports and small case series. While this type of prostheses represents a viable post-surgical rehabilitation option, primarily chosen for esthetic and functional benefits, evidence on their use in patients with documented acrylic hypersensitivity remains lacking. The low quality and limited number of studies highlight the need for prospective, controlled, and long-term research to clarify the role of nylon prostheses in post-surgical oral rehabilitation and to define their effectiveness in patients with material allergies.

Prosthesis doi: 10.3390/prosthesis7060168

Authors: Arturo González-Mendoza Ivett Quiñones-Urióstegui Aldo Alessi-Montero Irma Guadalupe Espinosa Jove Gerardo Rodriguez-Reyes Lidia Nuñez-Carrera

Background: Despite advances in myoelectric control of hand prostheses, their dropout rate remains high. Methods: We analyzed 37 features extracted from surface electromyography (sEMG) recordings from 15 participants, distributed into three groups: non-impaired individuals, impaired individuals with limb loss due to trauma, and impaired individuals with limb loss due to electrical burn. Feature relationships were examined with correlation heatmaps and two feature-selection methods (ReliefF and Minimal Redundancy Maximum Relevance), and classification performance was evaluated using machine-learning models to characterize sEMG behavior across groups. Results: Individuals with electrical-burn injury exhibited increased forearm co-contraction on the affected side across normalized isometric contractions, indicating altered motor coordination and likely higher energetic cost for prosthetic control. Feature selection and model results revealed etiology-dependent differences in the most informative sEMG features, underscoring the need for personalized, etiology-aware myoelectric control strategies. Conclusions: These findings inform the design of adaptive prosthetic controllers and targeted rehabilitation protocols that account for injury-specific motor control adaptations.

Prosthesis doi: 10.3390/prosthesis7060167

Authors: Riccardo Collu Elena Ferrazzano Verdiana Murgia Cinzia Salis Massimo Barbaro

The loss of a limb is an event that significantly affects an individual’s quality of life, with implications not only for autonomy in daily activities but also for their ability to interact with others. At the same time, current prostheses often fail to meet the user’s needs, resulting in high drop-out rates. In this review, we investigated the primary causes of prosthesis abandonment and analyzed them by highlighting the technological and psychological aspects associated with current devices. Technological issues due to reliability, functionality and comfort, together with psychological issues related to anxiety and depression, are among the main factors contributing to prosthesis rejection. Social aspects, sport, and community activities play crucial roles in improving the sense of belonging and acceptance of prosthesis users. Although research has often prioritized functionality, prosthesis development should follow patient-centered models that address the individual needs and requirements of patients, emphasizing psychological, rehabilitative, and technological support.

Prosthesis doi: 10.3390/prosthesis7060166

Authors: Adedotun Adetunla Chukwuebuka Anulunko Tien-Chien Jen Choon Kit Chan

Background: Advancements in low-cost additive manufacturing and artificial intelligence have enabled new avenues for developing accessible myoelectric prostheses. However, achieving reliable real-time control and ensuring mechanical durability remain significant challenges, particularly for affordable systems designed for resource-constrained settings. Objective: This study aimed to design and validate a low-cost, 3D-printed prosthetic arm that integrates single-channel electromyography (EMG) sensing with machine learning for real-time gesture classification. The device incorporates an anatomically inspired structure with 14 passive mechanical degrees of freedom (DOF) and 5 actively actuated tendon-driven DOF. The objective was to evaluate the system’s ability to recognize open, close, and power-grip gestures and to assess its functional grasping performance. Method: A Fast Fourier Transform (FFT)-based feature extraction pipeline was implemented on single-channel EMG data collected from able-bodied participants. A Support Vector Machine (SVM) classifier was trained on 5000 EMG samples to distinguish three gesture classes and benchmarked against alternative models. Mechanical performance was assessed through power-grip evaluation, while material feasibility was examined using PLA-based 3D-printed components. No amputee trials or long-term durability tests were conducted in this phase. Results: The SVM classifier achieved 92.7% accuracy, outperforming K-Nearest Neighbors and Artificial Neural Networks. The prosthetic hand demonstrated a 96.4% power-grip success rate, confirming stable grasping performance despite its simplified tendon-driven actuation. Limitations include the reliance on single-channel EMG, testing restricted to able-bodied subjects, and the absence of dynamic loading or long-term mechanical reliability assessments, which collectively limit clinical generalizability. Overall, the findings confirm the technical feasibility of integrating low-cost EMG sensing, machine learning, and 3D printing for real-time prosthetic control while emphasizing the need for expanded biomechanical testing and amputee-specific validation prior to clinical application.

Prosthesis doi: 10.3390/prosthesis7060165

Authors: Zanodumo Godlimpi Thanyani Pandelani

Background: This scoping review systematically maps and synthesises contemporary literature on the biomechanics of active below-knee prosthetic devices, focusing on gait kinematics, kinetics, energy expenditure, and muscle activation. It further evaluates design advancements, including powered ankle–foot prostheses and variable impedance systems, that seek to emulate physiological ankle function and enhance mobility outcomes for transtibial amputees. Methods: This review followed the PRISMA-ScR guidelines. A comprehensive literature search was conducted on ScienceDirect, PubMed and IEEE Xplore for studies published between 2013 and 2023. Search terms were structured according to the Population, Intervention, Comparator, and Outcome (PICO) framework. From 971 identified articles, 27 peer-reviewed studies were found to meet the inclusion criteria between January 2013 and December 2023. Data were extracted on biomechanical parameters, prosthetic design characteristics, and participant demographics to identify prevailing trends and research gaps. This scoping review was registered with Research Registry under the following registration number: reviewregistry 2055. Results: The reviewed studies demonstrate that active below-knee prosthetic systems substantially improve gait symmetry and ankle joint range of motion compared with passive devices. However, compensatory trunk and pelvic movements persist, indicating that full restoration of natural gait mechanics remains incomplete. Metabolic efficiency varied considerably across studies, influenced by device design, control strategies, and user adaptation. Notably, the literature exhibits a pronounced gender imbalance, with only 10.7% female participants, and a reliance on controlled laboratory conditions, limiting ecological validity. Conclusions: Active prosthetic technologies represent a significant advancement in lower-limb rehabilitation. Nevertheless, complete biomechanical normalisation has yet to be achieved. Future research should focus on long-term, real-world evaluations using larger, more diverse cohorts and adaptive technologies such as variable impedance actuators and multi-level control systems to reduce asymmetrical loading and optimise gait efficiency.

Prosthesis doi: 10.3390/prosthesis7060164

Authors: Rizwan Ahmed Malik Hussein Alrobei Muhammad Atiq Ur Rehman

Objectives: Burn being a major traumatic issue worldwide impacts millions of lives annually. Herein, a novel xanthan dialdehyde/sodium alginate/copper-doped mesoporous bioactive glass nanoparticle (XDA/Na-ALG/Cu-MBGN) hydrogel is presented in this study. Methods: The hydrogel was fabricated by a casting method, followed by its characterization in terms of its morphology, surface topography, and in vitro biochemical and physical interactions. Results: Scanning electron microscopy images revealed the rough surface of the hydrogel, ideal for cell attachment and proliferation. The nanoporous structure revealed by BET enabled it to hold moisture for an extended span. The nanopores were developed because of the ether linkage developed between XDA and Na-ALG, as evident from Fourier Transform Infrared Spectroscopy. The loading of Cu-MBGNs was also confirmed by FTIR. The release of copper ions was sustained throughout the 7 days, and it is accounting for about 22 µg/mL in 330 h, which follows the degradation kinetics of XDA/Na-ALG/Cu-MBGN hydrogels. The released copper ions promoted angiogenesis, as confirmed by the enhanced release of vascular endothelial growth factor (VEGF) for the XDA/Na-ALG/Cu-MBGN hydrogel (275 ng/mL) in comparison to 200 ng/mL of the bare TCP. The hydrogel, despite being bactericidal against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) did not show toxicity towards human dermal fibroblasts confirmed via a Water-Soluble Tetrazolium 8 assay. Conclusions: Hence, the developed XDA/Na-ALG/Cu-MBGN hydrogel possesses potential to be investigated further in terms of in vivo interactions.

Prosthesis doi: 10.3390/prosthesis7060162

Authors: Francesca Argenta Antonino Palazzolo Massimo Scanferla Tommaso Risciotti Eugenio Romeo Stefano Storelli

Objectives: The aim of this in vitro study was to evaluate the accuracy of intraoral impressions obtained using the Trios 3Shape® (3Shape Trios, Copenaghen, Denmark) and Carestream CS 3600™ (Carestream Dental, Stuttgart, Germany) scanners, compared with traditional polyvinyl siloxane (PVS) impressions. A laboratory scanner served as the gold standard. Materials and Methods: The study was based on 3D-printed master models derived from partially edentulous clinical cases previously treated at our department (2017–2022). All cases required at least two implants. Data analysis was performed using one-way ANOVA and two-sample Z-tests (α = 0.05) to compare mean deviations and variability. Results: All techniques demonstrated high accuracy, with deviations from the reference point below 30 μm. The digital intraoral scanners (Trios 3Shape® and Carestream CS 3600®) showed superior accuracy compared with PVS analog impressions, with no statistically significant difference between the two IOS systems. Conclusions: Within the limitations of this in vitro study, both IOS systems and PVS analog impressions achieved clinically acceptable accuracy. Digital systems exhibited improved performance in terms of mean deviation and consistency. The higher accuracy and consistency of digital impressions may translate into improved clinical efficiency and prosthetic fit in implant rehabilitations. From a clinical perspective, these in vitro findings suggest that digital impressions may enhance prosthetic fit and workflow efficiency, though further in vivo validation is required. Clinical significance: This study supports the reliability of intraoral scanning compared with conventional impressions in implant-supported rehabilitations. By demonstrating high intrinsic accuracy, these findings contribute to optimizing digital workflows in implant dentistry and reinforce the potential of intraoral scanning in static computer-guided, flapless implant surgery. Trial registration: Ethical approval and trial registration were not applicable to the present in vitro investigation, as no patients were directly involved in the experimental phase. The digital data used to generate the laboratory master models originated from a separate clinical study conducted at ASST Santi Paolo e Carlo, Milan (Ethics Committee approval no. 1361, 12 July 2017; ClinicalTrials.gov registration, Unique Protocol ID 1361).

Prosthesis doi: 10.3390/prosthesis7060163

Authors: Cristina Ayala Fernando Valencia Brizeida Gámez Hugo Salazar David Ojeda

Background: The need to improve gait emulation in people with amputation has driven the development of customized prosthetic mechanisms. This study focuses on the design and validation of a mechanism for external knee joint prostheses, based on the trajectory of the Instantaneous Center of Rotation (ICR) of a healthy knee. Objective: The objective is to design a mechanism that accurately reproduces the evolution of the ICR trajectory, thereby improving stability and reducing the user’s muscular effort. Methods: An exploratory methodology was employed, utilizing computer-aided design (CAD), kinematic simulations, and rapid prototyping through 3D printing. Multiple configurations of four- and six-bar mechanisms were evaluated to determine the ICR trajectory and compare it with a reference model obtained in the laboratory from a specific subject, using MATLAB-2023a and the Fréchet distance as an error metric. Results: The results indicated that the four-bar mechanism, with the incorporation of a simple gear train, achieved a more accurate emulation of the ICR trajectory, reaching a minimum error of 6.87 mm. Functional tests confirmed the effectiveness of the design in terms of stability and voluntary control during gait. It can be concluded that integrating the mechanism with the gear train significantly enhances its functionality, making it a viable alternative for the development of external knee prostheses for people with transfemoral amputation, based on the ICR of the contralateral leg.

Prosthesis doi: 10.3390/prosthesis7060161

Authors: Zainab Ahmed Abbas Haider Hasan Jasim

Background: Screw loosening is considered a leading mechanical complication in implant-supported restorations. Hybrid abutments, combining a titanium base with a ceramic mesostructured, were proposed to enhance stability and esthetics. Objective: We aimed to evaluate screw-loosening behavior in implant-supported zirconia restorations fabricated with various abutment designs. Methods: Thirty-six implant analogs were divided into three groups: (A) a one-piece hybrid abutment crown, (B) a two-piece hybrid zirconia abutment with a separated crown, (C) and a stock abutment with zirconia crown. Restorations were fabricated with CAD/CAM, bonded using a dual cure resin cement, and torqued to 35 Ncm to the analogs. The initial removal torque (RTV1) was measured, followed by thermal cycling and mechanical loading (500 cycles, 120,000 load cycles). The post-aging removal torque (RTV2) was measured and the torque loss percentage was calculated. Paired t-tests, ANOVA, and Tukey’s test were used (p < 0.05). Results: All groups demonstrated significant torque loss following aging (p < 0.001). Group A showed the highest torque loss (12.0%), while Groups B and C exhibited lower loss (7.6% and 7.9%, respectively). The between-group difference was statistically significant (p < 0.001), except for between Groups B and C (p = 0.53). Conclusions: Within the limitations of this in vitro study, the abutment configuration affected screw preload stability. The one-piece hybrid abutment crown showed greater torque loss after aging, while the two-piece and stock abutment designs maintained comparatively better stability. Further clinical studies are required to confirm these findings.

Prosthesis doi: 10.3390/prosthesis7060160

Authors: Carlos M. Ardila Diana María Pulgarín-Medina Eliana Pineda-Vélez Anny M. Vivares-Builes

Background/Objectives: Artificial intelligence (AI) is increasingly embedded in CAD/CAM workflows to address persistent challenges in restorative dentistry, including unpredictable color outcomes and time-intensive crown design steps. Yet, evidence on its accuracy and efficiency remains fragmented across heterogeneous study designs and metrics. This systematic review and meta-analyses aimed to evaluate the accuracy and performance of AI for color prediction and automated crown design in CAD/CAM ceramics. Methods: A systematic review with random-effects meta-analyses. The outcomes included design time, internal fit, finish-line accuracy, color-prediction acceptability using ΔE00 (AT00), morphology deviation, and occlusal and proximal contacts. Results: Fifteen studies met the inclusion criteria. The meta-analyses showed that AI-equipped CAD reduced crown design time compared to conventional CAD (MD −88.7 s; 95% CI −134.5 to −42.9; I2 = 72%). The internal fit showed a small advantage for AI (MD −17.1 µm; 95% CI −26.2 to −7.9; I2 = 90%). For finish-line identification, the pooled mean Hausdorff distance was ~0.35 mm (95% CI 0.316–0.382; I2 = 0%). For color prediction, the pooled proportion of predictions within each study’s prespecified acceptability threshold (AT00) was near-universal (0.996; 95% CI 0.988–0.999; I2 = 0%). Morphology and functional contacts were not pooled due to incompatible metrics and units. Narrative synthesis indicated AI performance comparable to, or favorable over, conventional/technician workflows in selected regions. Conclusions: AI for CAD/CAM dentistry shows practical promise, most clearly for design-time efficiency and with encouraging signals for internal fit, finish-line identification, and color-prediction acceptability under study thresholds. However, clinical translation should proceed cautiously.

Prosthesis doi: 10.3390/prosthesis7060159

Authors: Marzia Kareem Ahmed Aras Maruf Rauf

Background/Objectives: The precision and bonding reliability of space maintainers are critical to their clinical success longevity. This study aimed to evaluate and compare the fit accuracy and shear peel bond strength of digitally fabricated space maintainers—cobalt–chromium (Co-Cr) and polyetheretherketone (PEEK)—against conventional space maintainers. Methods: Seventy-eight space maintainer bands were fabricated—milled PEEK, selective laser-melted (SLM; an additive manufacturing technique) Co-Cr, and conventional stainless steel (SS)—and tested. Fit accuracy was evaluated on 39 bands by measuring the root mean square (RMS) deviation from a master model using digital 3D analysis. Shear peel bond strength (SPBS) was tested on another 39 samples using a universal testing machine, and the adhesive remnant index (ARI) was recorded after debonding. Statistical analyses included a Welch ANOVA for fit accuracy and the Kruskal–Wallis test for the SPBS test; the ARI was analyzed using Fisher’s exact test (significance level p < 0.05). Results: Digitally fabricated bands demonstrated significantly higher fit accuracy than the stainless steel bands (mean RMS deviation: Co-Cr = 0.151 mm, PEEK = 0.152 mm, SS = 0.344 mm; p < 0.001). Co-Cr and PEEK demonstrated comparable adaptation. In contrast, bond strength was significantly greater in Co-Cr (1.657 MPa) and SS (1.481 MPa) compared to PEEK (0.393 MPa). ARI distribution varied significantly across the three groups. Conclusions: Both milled PEEK and Co-Cr bands demonstrated excellent adaptation compared with conventional SS bands. However, Co-Cr exhibited reliable bonding performance, yet PEEK may require additional surface treatment or bonding optimization to enhance adhesion.

Prosthesis doi: 10.3390/prosthesis7060157

Authors: Susana João Oliveira Margarida Sampaio-Fernandes José Carlos Reis-Campos Manuel Sampaio-Fernandes Mário Augusto Pires Vaz Maria Helena Figueiral

Background/Objectives: Stability, retention, and support are removable partial denture (RPD) biomechanical principles. The literature shows contradictory opinions on indirect retention in RPDs, but no solid scientific evidence exists. This in vitro research aims to analyze indirect retainers’ (IRs) influence on forces transmitted to abutment teeth of a Kennedy Class I mandibular RPD. Methods: Bilateral distal-extension mandibular RPDs—differing only in the presence or absence of an IR on tooth 44 (IR model vs. nonIR model, respectively)—were installed on an acrylic master model. Tensile forces were applied perpendicularly to the occlusal plane on the longest free-end saddle’s distal aspect. Electronic speckle pattern interferometry (ESPI) measurements were obtained with and without an IR. The three-dimensional out-of-plane displacements of both models were acquired. Results: Abutment teeth 46 and 47 contralateral to the longest distal extension suffered more deformation under displacement forces when an IR was used. In turn, the IR’s influence on the deformation values of the abutment tooth 34 adjacent to the larger edentulous area depended on the intensity of the tensile force exerted: low-intensity forces resulted in reduced deformation, while higher-intensity forces resulted in higher deformation. Conclusions: This study’s findings indicate that indirect retention promotes better tensile force distribution in the existent teeth. However, they also question the IR’s role in protecting abutment teeth against excessive torque forces. This study’s preliminary results highlight the need for research on indirect retention principles using new methodologies, namely, in silico and ex vivo studies, and their experimental and clinical validation.

Prosthesis doi: 10.3390/prosthesis7060158

Authors: Reyam Zahir Alsultani Mohammed Kassim Gholam

Background: This study evaluated the influence of various decontamination protocols after salivary contamination on the micro-shear bond strength (µSBS) between monolithic high-translucency zirconia and resin cement. Methods: A total of 81 multilayer (ML) monolithic–translucent zirconia discs of 10 mm diameter and 2 mm thickness (DD cubeX2 ML, Dental Direkt) were fabricated, sintered, and polished using silicon–carbide papers. The bonding surfaces were treated with 50-μm Al2O3 using a Renfert sandblaster at 0.3 MPa for 20 s. Fifty samples were randomly assigned to five groups (n = 10). A control group consisted of clean, uncontaminated samples, while the other four groups were contaminated and cleaned using water, sodium hypochlorite, phosphoric acid + ethanol, or Ivoclean, respectively. Resin cement cylinders (Panavia V5, Kuraray Noritake) were bonded onto the zirconia surfaces. The µSBS was evaluated after simulated ageing using a universal testing machine. Failure modes were analysed by light microscopy. Surface morphology was evaluated using a field emission scanning electron microscope (SEM), and the chemical surface was assessed with X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared (FTIR) Spectroscopy. Surface wettability was assessed through contact angle measurements. One-way ANOVA with Tukey’s HSD was used to compare µSBS between groups. Results: Among the tested groups, the control group exhibited the highest µSBS value (59.5 ± 4.2 MPa), followed by Ivoclean (56.7 ± 4.8 MPa), phosphoric acid + ethanol (46.8 ± 4.7 MPa), and sodium hypochlorite (41.1 ± 5.7 MPa), with the lowest value observed with water (33.5 ± 6.3 MPa). All groups exhibited adhesive failure, with no sign of cohesive or mixed failures. SEM analysis showed no effect on zirconia crystallinity or sandblasting, while Ivoclean left residual zirconium oxide particles. Furthermore, XPS and FTIR analysis revealed favourable chemical changes after Ivoclean treatment, correlating with improved bonding performance. Contact angle measurements confirmed greater surface wettability in the Ivoclean group, resulting in strong bond strength. Conclusions: Ivoclean significantly increased the resin–zirconia bond strength after saliva contamination, showing more reliable results compared to others. Phosphoric acid + ethanol showed the second-highest mean strength, while water showed the least effectiveness.

Prosthesis doi: 10.3390/prosthesis7060156

Authors: Hend M. Elsayed Ahmed M. Elmarakby Salah A. Yousief Heba A. Abd Elwahab Moayad W. Alturki Eman M. H. Tawwash Hajar S. Albahkaly Kholud A. Rayes Hadeel A. Bawazir Hagar A. Samran Abdulaziz Samran Labib M. L. Elsebaey

Background: Gastroesophageal reflux disease (GERD) exposes restorative materials to gastric acid, which may compromise their esthetic and optical properties. Limited evidence exists regarding the performance of different CAD/CAM ceramics under acidic challenges. Methods: Forty CAD/CAM ceramic discs were prepared (n = 10 per group): high-translucency zirconia (Z; Ceramill Zolid Gen-X), lithium disilicate (E; IPS e.max CAD), zirconia-reinforced lithium silicate (S; VITA Suprinity), and hybrid ceramic (C; Cerasmart 270). Specimens were immersed in simulated gastric acid (0.06 M HCl, pH 1.2) at 37 °C for 96 h. Color difference (ΔE) and translucency parameter (ΔTP) were recorded before and after immersion using a spectrophotometer. Data were analyzed using one-way ANOVA with Tukey’s post hoc test (α = 0.05). Results: All materials exhibited changes in color and translucency after acidic immersion. Group Z demonstrated the lowest ΔE values, indicating the best color stability, whereas group C showed the highest ΔE and a significant reduction in ΔTP. Groups E and S revealed moderate but clinically acceptable changes. Intergroup differences were statistically significant (p < 0.05). Conclusions: Exposure to simulated gastric acid as in (GERD) resulted in measurable alterations in the optical properties of CAD/CAM ceramic materials. The extent of color change and translucency loss differed among the materials tested. High-translucency zirconia (Z) exhibited the greatest stability, while hybrid ceramic (C) showed the most pronounced changes. Zirconia-reinforced lithium silicate (S) and lithium disilicate (E) demonstrated moderate alterations, falling between these two extremes.

Prosthesis doi: 10.3390/prosthesis7060155

Authors: Vasileios K. Vergos Antonios L. Theocharopoulos Konstantinos Dimitriadis Stavros A. Yannikakis

Objectives: This in vitro study aimed to evaluate the effects of three framework orientation (FO) positions on an SLM building platform (Horizontal [H], Diagonal-45° [D45°], Diagonal-60° [D60°]) and two designs (with [B] or without [NB] stabilizing bars) on the fitting accuracy of digitally fabricated Co-Cr RPD frameworks. Materials and Methods: A custom RPD framework CAD was performed on a 3D-printed resin-model of an edentulous maxilla with three geometric tooth forms. A Co-Cr alloy was processed via SLM processing into 24 framework specimens, divided into three FO groups (n = 8: H, D45°, D60°) and two subgroups each (n = 4: B, NB). Qualitative/quantitative fit-evaluation was assessed using virtual framework-to-model seating and a custom digital protocol with GOM Inspect software (2018-Hotfix5, Rev.115656). Mean fitting distances were calculated from 220 equidistant points per specimen. Statistical comparisons were performed using ANOVA-on-ranks, Kruskal–Wallis multiple comparisons, and Bonferroni adjustment. Results: FO Sub-Group medians (Q1, Q3: 25% and 75% Quartiles) (mm) were: H/NB 0.150 (0.140, 0.164), H/B: 0.136 (0.121, 0.152), D45°/NB: 0.230 (0.219, 0.241), D45°/B: 0.144 (0.137, 0.154), D60°/NB:0.238 (0.232, 0.247), D60°/B: 0.171 (0.166,0.176). Pairwise comparisons indicated the following statistically significant (p < 0.05) FO Sub-Group differences: H/B-D45°/NB, H/B-D60°/NB, D45°/B-D45°/NB, D45°/B-D60°/NB, H/NB-D45°/NB, H/NB- D60°/NB. Conclusions: Horizontal orientation improved RPD fit accuracy regardless of bar presence. D45° accuracy is enhanced by stabilizing bars, while D60° accuracy is unaffected by bar addition.

Prosthesis doi: 10.3390/prosthesis7060154

Authors: Sergiu-Manuel Antonie Laura-Cristina Rusu Ioan-Achim Borsanu Emanuel-Adrian Bratu

Background: Material choice in full-arch implant-supported restorations significantly impacts longevity, complication rates, and patient satisfaction. This retrospective study compared monolithic zirconia versus hybrid metal–ceramic full-arch designs over a minimum three-year follow-up. Methods: Twenty patients (9 female, 11 male; mean age 55.4 ± 7.5 years) treated with full-arch implant-supported restorations were reviewed. Ten received monolithic zirconia restorations; ten received hybrid metal–ceramic. Clinical outcomes, including mechanical complications, prosthetic maintenance needs, opposing dentition wear, and patient-reported satisfaction (esthetics, comfort, masticatory function via VAS), were recorded. Statistical analyses were performed using Chi-square, independent t-tests, or Mann–Whitney U tests, with a significance level set at p < 0.05. Results: All implants (100%) and prostheses (>95%) survived. Monolithic zirconia exhibited no veneering chipping, while two events were observed in hybrid restorations (difference not statistically significant), and one bulk fracture occurred (monolithic). Hybrids had no framework fractures. Screw loosening occurred in one zirconia case. Mean VAS scores exceeded 9.0 in both groups; zirconia scored slightly higher for esthetics (9.4 ± 0.5 vs. 8.8 ± 0.6) and comfort (9.2 ± 0.6 vs. 9.0 ± 0.7). Polished zirconia resulted in no clinically detectable enamel wear, whereas hybrids with glaze loss caused occasional mild enamel wear but without functional impairment. Conclusions: Both restoration types show excellent survival and patient satisfaction over three years. Monolithic zirconia reduces veneering-related complications and maintenance, suggesting a possible advantage in functionally demanding cases with high occlusal loads or limited prosthetic space; hybrids may remain preferable when esthetic customization and gingival contour reproduction are paramount.

Prosthesis doi: 10.3390/prosthesis7060153

Authors: Jeffrey Cain Eric J. Earley Benjamin K. Potter Prateek Grover Peter Thomas Gerald Stark Ashlie White

Limb amputation is a growing health concern worldwide, driven largely by the rising incidence of vascular and metabolic diseases and military conflicts. In the past two decades, remarkable advancements in surgical techniques, prosthetic technologies, and rehabilitation strategies have made a profound impact on outcomes for individuals with limb loss. In this article, we explore the evolving landscape of limb care in the United States, highlighting innovations in prosthetic technology and amputation surgery including osseointegration, neuromuscular surgeries and interfaces, artificial intelligence, sensory feedback, and the importance of prosthetic embodiment. We discuss limb care systems and the continuum of limb loss rehabilitation, focusing on the need for coordinated models of patient-centered care. We present the demographic biases and healthcare disparities related to insurance coverage and reimbursement in the United States and the explore ethics and equitability considerations pertaining to prosthetic standard of care and advanced treatments for limb loss. Finally, we lay out the systemic reform, policy advocacy, and future research needed to ensure that everyone with limb loss has equitable access to the benefits of modern amputee care.

Prosthesis doi: 10.3390/prosthesis7060152

Authors: Pieralberto Valpiana Andrea Giordano Salvi Michele Paolo Festini Capello Fjorela Qordja Sebastian Schaller Jaeah Kim Pier Francesco Indelli

Background: Culture-negative periprosthetic joint infections (PJIs) are dramatically increasing in prevalence. The success rate of implant-saving procedures in acute PJI cases is closely correlated with prompt diagnosis, rapid isolation/identification of the microorganism, and timely surgical intervention. Methods: A 70-year-old female patient with an acutely infected left total hip arthroplasty (THA) following a routine screening colonoscopy was rapidly treated with debridement, antibiotic pearls, and retention of the implant (DAPRI) after rapid identification of the microorganism using a molecular diagnostics-based algorithm. Results: Molecular diagnostics enabled the identification of Escherichia coli as the causative agent of the transient bacteremia and subsequent seeding of the left hip within less than an hour. Conclusions: This case suggests that endoscopic procedures may increase the risk to joint replacement patients. In acute PJI, the use of molecular diagnostics, which facilitates prompt identification of microorganisms, may increase the success rate of implant-saving surgical procedures.

Prosthesis doi: 10.3390/prosthesis7060151

Authors: Bryar Abdulqadir Sharif Hawzhen Masoud Mohammed Saeed

Background/Objectives: Achieving durable intraoral repairs of fractured metal and zirconia restorations requires optimal adhesion. This in vitro study evaluated the effects of mechanical surface treatments and commercial repair systems on the shear bond strength (SBS) of composite resin to nickel–chromium (Ni-Cr) alloy and zirconia, including the influence of thermocycling aging. Methods: In this study, 144 Ni-Cr and zirconia discs (12 × 12 × 2 mm) were randomly assigned to three surface treatments: untreated control, airborne particle abrasion (50 µm Al2O3), and medium grit diamond bur grinding. Each group was further subdivided to assess two intraoral repair kits (GC Corp (Tokyo, Japan). and Bisco Inc. (Schaumburg, IL, USA)). Composite resin cylinders were bonded following the manufacturer’s instructions. Half of the specimens (n = 12/subgroup) underwent 5000 thermocycles (5–55 °C). Micro-shear bond strength testing was performed, and failure modes were analyzed. Data were analyzed using three-way ANOVA and post hoc tests (p < 0.05). Results: Air abrasion significantly increased SBS compared to control and bur grinding for metal (p < 0.001). For zirconia, both air abrasion and bur grinding yielded similarly improved SBS over the control (p < 0.001). The GC repair kit demonstrated significantly superior bond stability after thermocycling across both substrates. Aging significantly reduced SBS in all groups (p < 0.001), with the most substantial reductions observed in untreated controls and groups repaired with the Bisco system. Conclusions: Airborne particle abrasion combined with a HEMA-free, 10-MDP-containing universal adhesive achieved the strongest and most durable resin bonds to both metal and zirconia, supporting its clinical use for the intraoral repair of ceramic and metal restorations.

Prosthesis doi: 10.3390/prosthesis7060150

Authors: Peerada Weerayutsil Daraporn Sae-Lee Jarupol Suriyawanakul Pimduen Rungsiyakull Pongsakorn Poovarodom

Background/Objectives: This study aims to investigate the stress distribution and deformation of cobalt–chromium (CoCr) and polyetheretherketone (PEEK) maxillary bilateral distal-extension removable partial dentures (RPDs) on the abutment, periodontal ligament (PDL), mucosa, and RPD framework. Methods: A three-dimensional maxilla model was obtained from the patient’s cone-beam computed tomography (CBCT) and master model scan, composed of six maxillary anterior teeth, and U-shaped palatal major connectors for both the CoCr and PEEK RPD designs were constructed with computer-aided design (CAD) using the software program SolidWorks 2017 (SolidWorks Corp., Waltham, (MA), USA). A total vertical force of 320 N was applied bilaterally to the posterior artificial teeth. Three-dimensional finite element analysis was applied to evaluate the von Mises stress (VMS) distributions of the CoCr and PEEK RPDs on the abutment, PDL, mucosa, and RPD framework, and the deformation of the RPD framework was analyzed using ANSYS Workbench software, version 2020 (ANSYS Workbench 2020; ANSYS Inc.). Results: The stress distribution originated from the RPD free-end and was distributed to the mucosa, abutment, and PDL. The maximum stress observed in the oral structures was highest at the abutment, followed by the mucosa and PDL. The VMS occurring at the abutment in the CoCr RPD (9.098 MPa) was higher than that at the PEEK RPD (7.515 MPa), while the VMSs occurring at the mucosa and PDL in the CoCr RPD and PEEK RPD were similar. RPD frameworks constructed from different materials generated different stress distribution patterns. The maximum VMS occurring in the CoCr RPD framework (107.99 MPa) was significantly greater than that at the PEEK RPD framework (11.7 MPa). Meanwhile, the maximum deformation in the vertical direction of the PEEK RPD framework (0.0128 mm) was higher than that of the CoCr RPD framework (0.0082 mm). Conclusions: The results suggested that the PEEK RPD may have a better protective effect on the abutment. Both the PEEK and CoCr RPDs were unlikely to cause severe mechanical damage to the mucosa and PDL. However, the thickness of the PEEK framework should be focused on to reduce the stress distribution to the residual ridge mucosa.

Prosthesis doi: 10.3390/prosthesis7060149

Authors: Saja Kareem Esmael Faten Khalid Al-Kadi Jwan Fateh Abdulkareem Mohammed Abdalla Mahmood

Background/Objectives: Silicone elastomers are widely used in maxillofacial prostheses, but their service life is typically limited to 6–24 months due to progressive degradation. Reinforcement with zirconium silicate (ZrSiO4) nanoparticles has been proposed to improve durability, yet evidence on their long-term performance under storage remains limited. This study evaluated the effect of two years of dark storage on the mechanical properties of room-temperature-vulcanized (RTV) silicone reinforced with 1.5 wt% ZrSiO4 nanoparticles. Materials and Methods: Zirconium silicate (ZrSiO4) nanoparticles at 1.5 wt% were incorporated into A-2186 RTV silicone specimens, which were randomly divided into two equal groups: baseline specimens stored for 24 h and aged specimens stored for 24 months under dark conditions. Mechanical properties were assessed by measuring tensile strength, elongation at break, tear resistance, and Shore A hardness in accordance with standardized protocols. Fourier transform infrared (FTIR) spectroscopy was performed to verify the structural characteristics of the ZrSiO4 nanopowder. Statistical analysis was conducted using independent-samples t-tests, with significance set at p < 0.05. Results: After 24 months of dark storage, tensile strength and elongation at break decreased significantly (p < 0.05), indicating reduced elasticity. Tear resistance and hardness showed slight but non-significant reductions. FTIR confirmed the preservation of ZrSiO4 structural features. Conclusions: Dark storage selectively reduced reinforced silicone’s tensile and elongation properties, while tear resistance and hardness remained relatively stable. ZrSiO4 nanoparticles provided partial reinforcement, enhancing stability but not entirely preventing RTV silicone aging.

Prosthesis doi: 10.3390/prosthesis7060148

Authors: Alexis DuDash Bennett T. Amaechi Amos C. Obiefuna Sima Abdollahi Tejal Gohil Mustafa Girnary Stephan J. Haney Victoria A. Vickers Temitope O. Omosebi Mahalakshmi Vijayaraghavan

Background/Objectives: The present study investigated the effects on the mechanical and physical properties of PMMA when organoselenium was incorporated into it as antifungal at different concentrations. Methods: 141 PMMA rectangle samples were fabricated using a heat compression packing technique and assigned to 3 experimental groups (47/group): 0% organoselenium (control), 0.5% organoselenium (0.5% SE), and 1% organoselenium (1% SE). Each sample was post-processed and stored in water. A three-point bend test was performed to assess elastic modulus and flexural stress. Scanning electron microscopy (SEM) was used to examine the exterior and interior surface topography. Data were analyzed using one-way ANOVA with Tukey’s multiple comparisons test. Results: The mean flexure stress for the 0% samples was statistically significantly higher than those of the 0.5% samples and the 1% samples (p < 0.001). The mean elastic modulus for the 0% group was statistically significantly higher than those of the 0.5% group and the 1% group (p < 0.001). Under SEM, the 0.5% samples were smoother with fewer voids and irregularities. Conclusions: The incorporation of organoselenium into PMMA denture base negatively affected its physical and mechanical properties.

Prosthesis doi: 10.3390/prosthesis7060147

Authors: Andreea Kui Ana-Maria Condor Andreea Radulescu Andrea Maria Chisnoiu Bianca Dumbrovca Simona Iacob Marius Negucioiu Smaranda Buduru

Background/Objectives: The marginal adaptation of CAD/CAM restorations remains a key determinant of long-term clinical success, particularly in minimally invasive preparations. This in vitro study evaluated and compared the marginal gap of three CAD/CAM restorative materials—Cerasmart, G-CAM, and IPS Empress CAD—using standardized preparation and SEM measurement protocols. Methods: A total of 18 crowns were fabricated, of which 9 presented margins sufficiently interpretable under SEM and were included in the pooled quantitative analysis (n = 362 measurement points). Marginal gaps were recorded at 45×, 100× and 450× magnification using a Jeol JSM 25S scanning electron microscope. Normality and variance homogeneity were verified prior to parametric testing. Results: When pooled per material group, the mean ± SD marginal gap values were 18.53 ± 14.15 µm for Cerasmart, 21.60 ± 14.89 µm for G-CAM, and 47.09 ± 16.93 µm for IPS Empress CAD. All values fell below the contemporary clinical threshold of <70 µm for adhesive cementation. Pairwise comparison showed a large difference between IPS Empress CAD and the two resin-based materials, whereas the difference between Cerasmart and G-CAM was small. Conclusions: Hybrid and resin nano-ceramic CAD/CAM materials demonstrated narrower marginal gaps compared with the glass ceramic tested, likely due to their lower elastic modulus and greater seating accommodation during cementation. Within the limits of this in vitro design, all materials exhibited marginal adaptation consistent with current clinical acceptability criteria.

Prosthesis doi: 10.3390/prosthesis7060146

Authors: Chiyun Won

Background: Subcrestally placed implants (SPIs) present advantages for bone preservation and soft tissue support but pose challenges in maintaining peri-implant soft tissue health. This case explores the role of Crest to Restoration Distance (CRD) in the development and resolution of peri-implant mucositis. Case Presentation: A 57-year-old woman received two SPIs—one in the upper left and one in the lower right first molar region. Despite similar implant systems and prosthetic protocols, the upper left implant developed mucositis, characterized by bleeding on probing and discomfort, while the lower right implant remained stable. Three-dimensional analysis using cone-beam computed tomography (CBCT) revealed excessive CRD at the affected site. Results: After prosthodontic revision to reduce the CRD, clinical signs of mucositis resolved, with probing depths reduced to less than 1 mm and no bleeding on probing. The control site remained healthy throughout the observation period. Practical Implications: This case highlights CRD as a modifiable prosthetic factor influencing soft tissue stability. A three-zone model—comprising the sulcus, transitional zone (TZ), and subcrestal zone (SZ)—is introduced to provide a biologically grounded framework for understanding soft tissue adaptation around SPIs.

Prosthesis doi: 10.3390/prosthesis7060145

Authors: Haseeb H. Al Dary Layla A. Abu-Naba’a Hussein H. Helal Mahmoud M. Hasasna

Ceramic dental implants, particularly one-piece zirconia, offer a biocompatible and aesthetic alternative to titanium, with high strength and improved oral hygiene. By eliminating the implant–abutment micro-gap, they reduce bacterial accumulation because of their low plaque affinity and enhance stability. However, challenges remain, including alignment precision, limited retrievability, and sensitivity to mechanical stress. Misalignment can affect occlusal and functional outcomes, and zirconia’s rigidity complicates crown removal and modification. This case report explores the use of PEEK (polyether ether ketone) primary telescopic crowns to overcome these limitations, improving force distribution, enabling minor adjustments, and enhancing prosthetic retrievability in full-mouth zirconia restorations. A 62-year-old male patient seeking a fixed solution to replace removable dentures received 16 one-piece zirconia implants (eight per jaw). PEEK telescopic crowns were used over implant abutment copings, finalized with aesthetic zirconia bridges. The report details surgical and prosthetic procedures, along with a brief literature review on zirconia implants and PEEK applications. PEEK integration in telescopic prosthetic designs marks a notable advancement in prosthodontics. Its shock-absorbing, biocompatible, and stress-modulating properties make it valuable for implant-supported and hybrid restorations. As digital workflows advance, PEEK-based telescopic restorations may increasingly replace traditional metal-based solutions, improving long-term clinical outcomes. Further clinical research on a larger sample is needed.

Prosthesis doi: 10.3390/prosthesis7060144

Authors: Mattia Concari Gianfranco D’Avino Michele Bertolini

Purpose: This study investigates the static mechanical behavior of a non-modular metallic hip prosthesis through Finite Element Method (FEM) simulations, assessing compliance with ASTM F2996-13 standards. The analysis specifically evaluates how key geometric parameters, such as trunnion extension and orientation angles (adduction and flexion), affect stress distributions within the prosthesis. Methodology: A three-dimensional finite element model of a Ti6Al4V alloy hip stem was developed. Boundary and loading conditions were defined according to the standard: the distal portion of the stem was fully constrained 90 mm below the head center, and a static load of 2300 N was applied at the head center along the directions defined by the adduction and flexion angles. A mesh sensitivity analysis was conducted to ensure convergence, and stresses were evaluated. Parametric analyses varying trunnion extension and orientation angles were performed to quantify their impact on local stress concentration. Results: The findings revealed that even minor deviations in the adduction and flexion angles significantly impact the stress distribution, with the potting-level region being particularly sensitive. Additionally, the extension of the trunnion led to notably increased stress concentrations, especially at the prosthesis neck, highlighting its critical influence in implant design. Conclusions: Comparison with existing literature and standard reference data exposed discrepancies primarily attributed to variations in FEM model setups and parameter selections. This emphasizes the necessity of clearly specifying trunnion extension and orientation angles in numerical analyses to ensure consistent stress predictions, supporting the development of safer and longer-lasting hip implants. Future research should extend these analyses to different prosthesis geometries, aiming to develop generalized predictive frameworks applicable to diverse biomechanical scenarios.

Prosthesis doi: 10.3390/prosthesis7060143

Authors: Renjith Rajan Pillai Lakshmi Mohan

Plasma surface modification has emerged as a powerful, versatile tool for tailoring the surface properties of biomedical devices and implants without altering the material characteristics in the bulk. This comprehensive review critically examines the current state-of-the-art in plasma-based surface engineering techniques, with a focus on enhancing biocompatibility, bio-functionality, and long-term performance of medical implants. The article systematically explores various plasma processes and their roles in modifying surface chemistry, topography, energy, and wettability. These alterations directly influence protein adsorption, cell adhesion, antibacterial activity, and corrosion resistance, all of which are crucial for successful clinical integration. Special emphasis is placed on the plasma treatment of metallic (e.g., titanium, stainless steel), polymeric (e.g., polytetrafluoroethylene, polyetheretherketone), and composite substrates commonly used in dental, orthopedic, and cardiovascular applications. This review also highlights synergistic strategies, such as plasma-assisted grafting of bioactive molecules and nanostructuring, that enable multifunctional surfaces capable of promoting osseointegration, mitigating inflammation, and preventing biofilm formation. Emerging trends such as atmospheric cold plasmas and the integration of plasma technology with additive manufacturing are outlined as promising future directions. By synthesizing insights from surface science, materials engineering, and biomedical research, this review provides a foundational framework to guide future innovations in plasma-treated biomaterials. It aims to inform both academic researchers and medical device developers seeking to optimize implant–tissue interactions and achieve improved clinical outcomes.

Prosthesis doi: 10.3390/prosthesis7060142

Authors: Fotios Bakouros-Kouroupakis Ioannis Tsolianos Eleni Kotsiomiti

Background: Tooth development or odontogenesis is a complicated, multi-staged process, regulated by a plethora of genes. Disruptions during the early stages of odontogenesis may cause the complete absence of one or more teeth, known as tooth agenesis (TA). Except for PAX9, alterations in MSX1, AXIN2, WNT10A, and EDA/EDAR/EDARADD have gathered an increasing amount of interest. Objectives: This systematic review aims to investigate whether non-syndromic tooth agenesis (NSTA) is associated with MSX1, AXIN2, WNT10A, and EDA/EDAR/EDARADD mutations and to list the related phenotypic patterns of these alterations with regard to missing teeth. Methods: MEDLINE, Scopus, and Web of Science were the three selected databases. Duplicates were removed using Mendeley, and the records were assessed via the Rayyan platform. The Newcastle–Ottawa Scale was used to evaluate the quality of the evidence. Results: Fifteen case–control studies were eligible for this systematic review. The MSX1 gene was examined in most studies, whereas second premolars and lateral incisors were the most commonly missing teeth among TA cases. In total, 61.29% to 84.9% of the cases included one or two absent teeth. Conclusions: Due to the considerable heterogeneity in reporting results across the included studies, along with the high risk of bias present in most of them, it was not feasible to conduct a meta-analysis of the data. Nonetheless, the findings suggest that the NSTA phenotypes linked to the studied genes are similar to those associated with other forms of TA and share a common pattern of missing teeth. Future research should adopt a more standardized approach in presenting findings by adhering to established terminology and definitions and by utilizing common cut-off points to categorize results.

Prosthesis doi: 10.3390/prosthesis7060141

Authors: Mohamed Aissi Azzedine Er-ramly Nadia Merzouk

Objective: The Ti6Al4V titanium alloy is widely used for dental implants because of its excellent mechanical properties, corrosion resistance, and biocompatibility. However, its bioinert surface limits both osseointegration and resistance to bacterial colonization. Methods: To address these challenges, this study develops a composite coating based on calcium phosphate (CaP) and silver (Ag), reinforced with zirconium oxide (ZrO2). The coating was deposited on Ti6Al4V using an immersion technique to improve the surface properties of the alloy. Electrochemical analyses (OCP, EIS, and potentiodynamic polarization) were performed in simulated physiological conditions to evaluate the corrosion behavior, while SEM/EDS was used to characterize the surface morphology and composition. Results: The Ag- and Zr-containing CaP coatings significantly improved the corrosion resistance of Ti6Al4V compared with uncoated and CaP-coated samples. Conclusions: This approach provides a promising strategy to enhance the electrochemical stability and long-term durability of titanium dental implants, thereby contributing to their reliable performance in the oral environment.

Prosthesis doi: 10.3390/prosthesis7060140

Authors: Hend Mohamed Elsayed Hajar Sameer Albahkaly Abdulaziz Samran Mohammed Noushad Abdulaziz Abdullah Alkheraif Nisreen Alansary Mohammad Zakaria Nassani

Background/Purpose: Teeth prepared for fixed dental prostheses are subject to various types of insults in the oral cavity. Therefore, to protect the tooth, the pulp, and supporting structures, provisional restorations are mandatory. Our study aimed to evaluate the knowledge and clinical practices regarding provisional fixed dental prostheses (PFDPs) among dental professionals in Saudi Arabia. Materials and Methods: A cross-sectional study based on a self-administered online survey was conducted among 312 dentists (general practitioners and specialists) across Saudi Arabia. The questionnaire assessed participants’ knowledge (11 items) and clinical practices (9 items) related to PFDPs. Statistical analyses included descriptive statistics, chi-square tests, and multivariate logistic regression. Results: Only 46.5% of respondents demonstrated adequate knowledge of PFDPs. Knowledge was significantly higher among specialists than general practitioners (57.4% vs. 41.7%, p = 0.011), and specialists were more likely to recognize the influence of PFDPs on treatment outcomes. Clinical practice patterns indicated that even though 94.2% of respondents frequently placed PFDPs, only 66.0% always did so. Moreover, 21.2% of respondents rarely or never disinfect PFDPs. Public sector dentists and specialists were more likely to use custom-made PFDPs. Key gaps in knowledge were observed regarding the materials and equipment used in the fabrication of PFDPs, particularly concerning CAD/CAM technology. Conclusions: Although most dentists in Saudi Arabia provided PFDPs to their patients, significant gaps remain in their knowledge, particularly regarding fabrication materials and techniques. Targeted educational interventions, especially for general practitioners, are needed to enhance clinical outcomes.

Prosthesis doi: 10.3390/prosthesis7060139

Authors: Muhammad Amber Fareed Mazen Abdulmounem Masri Almustafa Wisam Mustafa Al-sammarraie Buthena Mohamed Ehsan Akil

Background: Fiber-reinforced composites (FRCs) have emerged as transformative materials in restorative dentistry, particularly for managing partial edentulism through fixed partial dentures (FPDs). Their superior aesthetic, mechanical, and adhesive properties offer a minimally invasive alternative to traditional metal–ceramic restorations. Objective: This review aims to evaluate the historical evolution, clinical applications, technological advancements, and prospects of FRCs in prosthodontics, emphasizing their potential to deliver durable, aesthetic, and cost-effective treatment solutions. Methods: This narrative review follows the SANRA guidelines. A comprehensive literature search was conducted across PubMed, ScienceDirect, and Google Scholar for studies published between January 1995 and January 2025. Search terms included “fiber-reinforced composite”, “fixed prosthodontics”, “fixed partial dentures”, “adhesive restorations”, and “implant-supported restorations”. Only English-language studies addressing the clinical applications, mechanical properties, technological innovations, or survival outcomes of FRCs were included. Data were extracted from original research papers, systematic reviews, and narrative reviews. Results: Advancements in fiber architecture, resin matrices, and polymerization techniques have enhanced the strength, aesthetics, and longevity of FRC-based FPDs. Their high flexural strength, fatigue resistance, and compatibility with adhesive restorative techniques provide clinicians with versatile treatment options. Clinical studies demonstrate favorable survival rates and long-term success, positioning FRC FDPs as reliable alternatives to conventional restorations. Emerging technologies such as CAD/CAM and 3D printing further broaden their scope and precision. Conclusions: FRC FPDs have evolved from interim solutions to predictable, long-term restorations. With ongoing technological innovations and clinical validation, they are poised to become a mainstream treatment choice in prosthodontics. FRC FPDs offer a durable, aesthetic, and cost-effective solution aligned with minimally invasive dentistry, reducing tooth preparation while improving patient-centered outcomes.

Prosthesis doi: 10.3390/prosthesis7060138

Authors: Marta Mazur Artnora Ndokaj Stephen Westland Livia Ottolenghi Francesca Ripari Roman Ardan Marina Piroli Roberta Grassi Gianna Maria Nardi

Background/Objectives: Tooth colour perception is critical to aesthetic outcomes in restorative dentistry and patient satisfaction. Psychological and gender-related factors may modulate individual colour perception. This study evaluates the influence of gender and emotional state on tooth colour self-perception in healthy adults. Methods: A prospective observational study was conducted on 100 adults (50 women, 50 men; mean age 32.2 years) without anterior restorations or systemic disease. Tooth shade was assessed by (i) operator visual matching using the VITA Classical A1–D4 guide, (ii) patient self-selection with the same guide, and (iii) spectrophotometric measurement (Spectroshade Micro). Emotional state was measured using the abbreviated Profile of Mood States (POMS-SF); the OHIP-14 was administered to characterise oral health–related quality of life. Statistical analyses included the Chi-squared test, Kendall’s τ, and t-test, with p < 0.05 considered significant. Results: A significant association between gender and the magnitude of patient–operator discrepancy was found (p = 0.013): women showed higher rates of complete agreement or two-step differences, whereas men more frequently exhibited one-step differences. Positive mood parameters (feeling active, energetic, satisfied) correlated with greater patient–operator agreement (τ = 0.17–0.23, p < 0.05). Significant association was neither observed between patient self-selection and spectrophotometric measurement (p = 0.225), nor between facial undertone, facial colour contrast, or depressive mood levels. Conclusions: Gender and emotional state influence subjective tooth colour perception. Positive mood is associated with improved agreement between perceived and clinically assessed colour. These findings support a personalised, gender- and mood-informed approach to shade selection and patient management in aesthetic dentistry.

Prosthesis doi: 10.3390/prosthesis7060137

Authors: Saverio Ceraulo Gianluigi Caccianiga Dorina Lauritano Francesco Carinci

Background/Objectives: This retrospective study aimed to evaluate the five-year clinical performance of removable partial dentures (RPDs) made of chromium–cobalt–molybdenum alloy, comparing two different post-casting cooling methods: slow furnace cooling (LRF) and room temperature air cooling (RATA). The investigation aimed to determine whether LRF treatment could reduce the incidence of technical complications, such as fractures and clasp deformations, particularly on RPD with thin clasps for aesthetic reasons. Methods: In total, 22 RPDs were examined, 11 of which were treated with LRF (test group) and 11 with RATA (control group). The prostheses in the LRF group had clasps intentionally reduced by 2/3 tenths of a millimeter compared to those in the RATA group. All the prostheses were made and evaluated by the same operator, who analyzed the presence of changes, fractures, or clasp widening after five years. Statistical analysis was performed using Fisher’s exact test with a significance level of p < 0.05. Results: Clinical data showed a lower complication rate in the LRF group compared to the RATA group in all parameters evaluated: prosthesis modification (9.1% vs. 18.2%), clasp fractures (9.1% vs. 36.4%), and enlarged clasps (54.4% vs. 72.7%). However, the statistical comparison between the two groups did not show significant differences, p-value ˃ 0.05 for all parameters. Conclusions: Despite the lack of statistical significance, likely due to the limited size of the cambium and the confounding variable of clasp thickness, clinical trends indicate a potential superiority of the LRF method in the parameters examined, such as modification prosthesis, fractured clasp, and enlarged clasp. The reduction in complication rates in the LRF group suggests that the superior mechanical properties conferred by this treatment may compensate for the potential structural weakening caused by clasp thickness. Future studies with a larger sample size and a prospective design will be needed to validate these results and confirm LRF as the preferred protocol for the production of aesthetic RPD.

Prosthesis doi: 10.3390/prosthesis7060136

Authors: Cong Ma Elizabeth Gibson Mirella Di Lorenzo Patrick Degenaar

As the world’s population ages, the incidence of chronic disorders is on the rise. Active Implantable Medical Devices are, therefore, evolving to meet the challenge. As the size of these devices decreases to facilitate implantation, the challenge of providing stable, continuous power becomes significant. Lithium batteries provide reliable, stable power to implants; however, their miniaturization leads to a reduction in the stored energy capacity, total lifespan, and overall capability. Consequently, there is a need for on-body energy harvesting alternatives. This study utilizes literature data on abiotic glucose fuel cells to feed into a finite element model incorporating both diffusion and reaction aspects to investigate how the 3D macro-architecture of the fuel cell device can be used to optimize the energy output. Accordingly, optimal 3D architectures are determined to enable power outputs ranging from several tens of microwatts to one hundred microwatts from an implantable package. This will help with the 3D architecture design of future similar abiotic fuel cell units and speed up the process of figuring out the best settings for key parameters (like shape, size, and separation).

Prosthesis doi: 10.3390/prosthesis7060135

Authors: Ioan-Achim Borșanu Laura-Cristina Rusu Sergiu-Manuel Antonie Emanuel-Adrian Bratu

Background: This retrospective comparative clinical study aimed to evaluate the performance of digital versus conventional impression techniques in the fabrication of implant-supported prosthetic restorations. Materials and Methods: A total of 40 cases were included: 20 impressions obtained with conventional elastomeric materials (polyvinyl siloxane and polyether), and 20 impressions acquired digitally using two intraoral scanners (TRIOS 3 and Medit i700). All patients received partial fixed implant restorations and were documented across all stages of prosthetic treatment. Accuracy and passive fit were assessed using radiographic measurements and the Sheffield test. Linear distances (mm) at the implant–abutment interface, chairside time (min), and VAS scores (1–10) were analyzed. Clinical efficiency was evaluated based on procedural steps, chairside time, and adjustment frequency. Patient satisfaction was assessed through a structured 10-item Visual Analog Scale (VAS) questionnaire. Results: Results showed a lower misfit rate in the digital group (15%) compared to the conventional group (25%), with no final-stage misfits in digital cases. Digital workflows demonstrated shorter impression times, fewer procedural steps, and reduced the need for prosthetic adjustments. Patient satisfaction scores were significantly higher in the digital group across all VAS parameters (p < 0.001), particularly in comfort and esthetic satisfaction. Conclusions: These findings support the use of digital impressions as a clinically efficient and patient-preferred alternative to conventional methods for partial implant restorations. However, conventional impressions remain a viable option in settings where digital technology is not available. Further studies with larger sample sizes and long-term follow-up are recommended to assess outcomes in full-arch rehabilitation.

Prosthesis doi: 10.3390/prosthesis7060134

Authors: Yasuhiro Matsuda Nobuaki Magata Naomi Tanoue

Background/Objectives: Mandibular advancement oral appliances (MAOAs) for obstructive sleep apnea syndrome treatment can be rendered more convenient by adopting a separate and movable design; however, concerns regarding possible weakening of effect have been raised. This study had the aim to clarify the factors associated with the longevity of separate and movable MAOAs. Methods: Information on 466 MAOAs from 230 patients was collected from medical records, including baseline information, apnea–hypopnea indexes, transcutaneous oxygen saturation, component connection method, and initial fabrication status (new fabrication or repair). MAOAs were evaluated in clinical practice, and breakage was considered a failure. Failures were classified into three types: Type A, breakage anywhere in MAOA; Type B, connector breakage (thermoplastic component breakage was censored); and Type C, thermoplastic component breakage (connector breakage was censored). Survival time of MAOA for all types was analyzed using a shared frailty model. Hazard ratios and 95% confidence intervals were determined, with the statistical significance at p < 0.05. Results: Type A failures were significantly linked to patient sex, age, and connection method; Type B failures were associated with sex and age; and no variables were linked to Type C failures. Younger male patients showed lower survival rate except for Type C, with no correlation between apnea symptom severity and survival status. Conclusions: MAOA connector strength was significantly associated with the MAOA survival rate. Connectors were more likely to break in younger patients, and this tendency was particularly pronounced in males. Therefore, age and sex should be considered when choosing the MAOA connection method.

Prosthesis doi: 10.3390/prosthesis7060133

Authors: Maxim Shevtsov Ekaterina Bozhokina Natalia Yudintceva Danila Bobkov Anastasiya Lukacheva Denis Nazarov Irina Voronkina Larisa Smagina Emil Pitkin Elena Oganesyan Airat Kayumov Grigory Raykhtsaum Mykhailo Matviychuk Vladimir Moxson Michael Akkaoui Stephanie E. Combs Mark Pitkin

Background/Objectives: A comparative study of silver (Ag), titanium nitride (TiN), zirconium nitride (ZrN), and copper (Cu) coatings on titanium (Ti) disks, considering the specifications of a microporous skin- and bone-integrated titanium pylon (SBIP), was performed to assess their biocompatibility, osseointegration, and mechanical properties. Methods: To assess cytotoxicity and biocompatibility, Ti disks with various metal coatings were co-cultured with FetMSCs and MG-63 cells for 1, 3, 7, and 14 days and subsequently evaluated using a cell viability assay, as supported by SEM and confocal microscopy studies. The antimicrobial activity of the selected four materials coating the implants was tested against S. aureus by mounting Ti disks onto the surface of LB agar dishes spread with a bacterial suspension and measuring the diameter of the growth inhibition zones. Quantitative Real-Time Polymerase Chain Reaction (RT-PCR) analysis of the relative gene expression of biomarkers that are associated with extracellular matrix components (fibronectin, vitronectin, type I collagen) and cell adhesion (α2, α5, αV integrins), as well as of osteogenic markers (osteopontin, osteonectin, TGF-β1, SMAD), was performed during the 14-day follow-up period. Additionally, the activity of matrix metalloproteinases (MMP-1, -2, -8, -9) was assessed. Results: All samples with metal coatings, except the copper coating, demonstrated a good cytotoxicity profile, as evidenced by the presence of a cellular monolayer on the sample surface on the 14th day of the follow-up period (as shown by SEM and inverted confocal microscopy). All metal coatings enhanced MMP activity, as well as cellular adhesion and osteogenic marker expression; however, TiN showed the highest values of these parameters. Significant inhibition of bacterial growth was observed only in the Ag-coated Ti disks, and it persisted for over 35 days. Conclusions: The silver-based coating, due to its high antibacterial activity, low cytotoxicity, and biointegrative capacity, can be recommended as the coating of choice for microporous titanium implants for further preclinical studies.

Prosthesis doi: 10.3390/prosthesis7060132

Authors: Kevin Wendo Séverine Guisset Kiswendsida Sawadogo Olivier Barbier Arnaud Meunier Axele Felloneau Thierry Oquidam Thomas Lhermitte Brice Adornato Morgan Jimenez Raphael Olszewski

Background: 3D printing (3DP) workflow has made its entry in the upper limb prostheses (ULP) manufacturing process. Although it represents a valuable change in clinical practice, its implementation is not ubiquitous. Additional data are required to establish recommendations and unanimously accepted guidelines to facilitate clinical application. Objectives: Our study aimed to develop and validate a web-based multilingual survey investigating the sociodemographic and technical profiles and expertise of professionals and volunteers using 3DP for manufacturing ULP. Methods: We followed a multi-stage development and validation process, including item generation, experts’ review, cognitive testing and pre-testing among the population of interest (POI). Validity evidence was accumulated at each stage, with Content Validity and Face Validity measurements. The survey was available in French, English and Spanish and distributed through the REDCAP web-based platform. Results: The validated questionnaire comprised fifty-two primary questions, organized in nine sections. Experts’ evaluations demonstrated appropriate topic coverage and a high degree of relevance throughout the survey: most single item Content Validity Indexes (CVI) ranged from 0.87 to 1 and Average CVIs for survey sections reached between 0.86 to 1. The pre-test among the POI included 42 participants and led to limited questionnaire revisions. The final version of the survey was approved unanimously by all experts. Conclusions: The newly developed web-based survey demonstrated good evidence for validity. This instrument is an acceptable tool to investigate stakeholders using 3DP for manufacturing ULP and to further establish guidelines.

Prosthesis doi: 10.3390/prosthesis7060131

Authors: Ali-Reza Ketabi Stefan Hassfeld Laurentia Schuster Sandra Ketabi Julius Stueben Andree Piwowarczyk

Background: This study analysed whether vertical measurements in the maxillary posterior region are more accurate using panoramic radiography (PAN) or cone-beam computed tomography (CBCT). Methods: Corresponding maxillary posterior regions on both PAN and CBCT images were selected and examined for vertical measurements. The vertical distance between the bone crest and the floor of the maxillary sinus was measured. Measurements in edentulous regions were performed using a similar procedure. Additionally, the vertical height of any defect, if present, was measured. Results were evaluated statistically. Results: When comparing corresponding regions on the CBCT and PAN images, 204 patients with a total of 341 measurements (n = 341) met the inclusion criteria. The mean values for all measurements were 7.21 ± 3.74 mm on PAN and 7.62 ± 4.06 mm on CBCT. The mean difference between all paired measurements was −0.41 ± 1.03 mm. Significant differences between PAN and CBCT were observed (p < 0.001). Defects were detected in 58 (17%) of the 341 measurements. The mean defect height was 1.85 ± 1.05 mm on PAN and 1.99 ± 1.00 mm on CBCT. No significant differences were noted between PAN and CBCT (p = 0.052). Conclusions: Although the relationship between vertical height measurements on PAN and CBCT showed a significant difference of −0.41 ± 1.03 mm for all paired measurements, the difference was very small upon closer inspection. Both PAN and CBCT are suitable methods for measuring vertical heights in the posterior maxilla.

Prosthesis doi: 10.3390/prosthesis7050130

Authors: Pilar Barahona Braulio Santibáñez Andrés Celis Gerardo Fasce Erik Dreyer

Introduction: Removable dental prostheses (RDPs) are essential for chewing, nutrition, and preventing geriatric syndromes in older adults. Evidence regarding their benefits varies. Objective: To compare two groups of elderly individuals aged 70 and above from public and private health systems, assessing changes in hand grip strength (HGS) adjusted for masticatory function, malnutrition risk, and body mass index (BMI) after using dental prostheses. Method: A prospective pre–post study. Between March 2020 and 2023, elderly individuals aged 70 or older who used public and private health systems and lacked molars and premolars were included. They were categorized based on chewing ability according to the Eichner index and assessed for malnutrition risk using calf circumference (CC) and BMI. HGS was measured at baseline and 15 days after prosthetic use using a hydraulic manual dynamometer (Jamar™). Differences in HGS were analyzed with a mixed linear regression model using SAS 9.4 software (p < 0.05). Results: n= 248 (124 public/124 private), sex 73/73 women (p > 0.05), ages 81.2/75.2 years (p < 0.0001), and malnutrition risk based on CC 5/31 (p < 0.0001). In a multivariate model adjusted for sex, age, BMI, and malnutrition risk, the HGS before using prostheses was 22.8 kg/11.7 kg (Δ = 11.1 kg; p < 0.0001), and afterwards it was 23.0 kg/14.2 kg (Δ = 8.8 kg; p < 0.0001). Conclusions: RDPs immediately improved HGS in older adults from both public and private health systems, with significant differences of up to 8.8 kg between the two groups.

Prosthesis doi: 10.3390/prosthesis7050129

Authors: Oscar Javier Valencia-Blanco Esteban Pérez-Pevida Daniel Robles-Cantero Enrique Montalvillo Javier Gil Aritza Brizuela-Velasco

Objective. The aim of this in vitro study was to compare the physical and mechanical properties of two resins used for provisional prostheses: a direct self-curing dimethacrylate resin and a 3D-printed resin, in order to assess their potential for different clinical applications. Methods. Flexural strength, microhardness, wear resistance, and water absorption were evaluated in accordance with ISO 4049 and ISO 10477. Samples were analyzed using scanning electron microscopy, X-ray spectroscopy, and mechanical testing, including flexural, wear, and scratch assays. Results. The 3D-printed resin demonstrated superior flexural strength (128 ± 2 MPa vs. 127 ± 16 MPa), microhardness (19.45 HV vs. 8.10 HV, p < 0.05), and wear resistance (mean wear area: 0.030 mm2 vs. 0.047 mm2) compared to the self-curing dimethacrylate composite. However, it exhibited significantly higher water absorption (55.98 µg/mm3 vs. 15.0 µg/mm3), which may compromise its long-term durability in humid environments. Conclusions. Overall, the 3D-printed resin shows promising mechanical performance, but its high-water absorption remains a limitation for extended use. Further studies are required to evaluate its degradation and behavior under intraoral conditions. Clinical relevance. For the time being, self-curing resins remain the preferred choice for long-term provisional prostheses.

Prosthesis doi: 10.3390/prosthesis7050128

Authors: Saidan Shetty G Arun Maiya Mohandas Rao KG Sandeep Vijayan Shetty Shrija Jaya Bincy M George

Background/Objectives: Knee osteoarthritis (OA) alters lower limb biomechanics, often leading to an asymmetric plantar pressure distribution. Total knee arthroplasty (TKA) aims to restore joint function and may normalize plantar loading, but evidence from instrumented static pressure analysis is limited. The objective of this study was to compare static plantar pressure distributions before and after TKA in individuals with knee OA and in age- and sex-matched healthy controls. Methods: A pre-post study was conducted on 77 individuals with severe knee OA (Kellgren–Lawrence grade 4) who underwent TKA and 77 matched healthy controls. The plantar pressure area, average pressure, and maximal pressure were assessed preoperatively and at 6 and 12 months postoperatively using a Win-Track force platform. Standard postoperative rehabilitation was followed. Statistical analyses included independent t-tests and repeated-measures ANOVA (p ≤ 0.05). Results: Compared with controls, pre-TKA patients presented significantly lower plantar pressure area, average pressure, and maximal pressure than controls (p < 0.001). At 6 and 12 months post-TKA, the plantar pressure area (p < 0.001) and average pressure (p = 0.001) improved significantly, with more balanced bilateral loading and increased forefoot weight transfer. At 12 months, no significant differences in any plantar pressure parameters remained between the TKA and control groups. Conclusions: Severe knee OA is associated with altered static plantar pressure patterns, characterized by reduced loading and asymmetry. TKA effectively restores plantar pressure distribution, achieving normalization within 12 months. The incorporation of plantar pressure assessment into pre- and postoperative care may guide targeted rehabilitation and enhance functional recovery.

Prosthesis doi: 10.3390/prosthesis7050127

Authors: Bennett Hendricks Arian Pakray Joshua Thomas Serly Tomas Malli Barremkala Jickssa Gemechu

Penile prosthetic implants (PPIs) provide a definitive surgical solution for individuals requiring restoration of erectile function, most commonly due to medication-refractory erectile dysfunction (ED) or as part of gender-affirming surgical care. During the Anatomical Foundations of Clinical Practice (AFCP) course at Oakland University William Beaumont (OUWB) School of Medicine, a complete three-piece inflatable PPI was identified in a 66-year-old male donor with a medical history of congestive heart failure, hypertension, and diabetes mellitus type 2. The prosthesis included a fluid reservoir positioned in the lower abdominal cavity in the retropubic space, a scrotal pump with a release valve, and paired inflatable cylinders embedded within the penile shaft. This uncommon finding provided first-year medical students with a hands-on opportunity to examine the structure, placement, and function of a modern PPI. In addition to reinforcing foundational knowledge of ED treatment, the case highlighted the expanding clinical indications for penile implants, including their potential role in gender-affirming procedures. Integrating such real-world surgical findings into anatomical education enriches the learning experience of students and highlights the evolving scope of prosthetic urology across diverse patient populations.

Prosthesis doi: 10.3390/prosthesis7050126

Authors: Ioan Száva Iosif Șamotă Teofil-Florin Gălățanu Dániel-Tamás Száva Ildikó-Renáta Száva

Long bone fractures are breaks or cracks in a long bone of the body typically caused by trauma like a fall, sport injury, accidents etc. This study investigates the effectiveness of experimental methods for fast and safe healing of long bone fractures in humans, highlighting both their advantages and disadvantages, respectively finding the most effective and safe methods for evaluating the types of fixators that can be used in the consolidation of fractured long bones. As for the preliminary data, numerical methods and applied mathematics were used to address this problem. After collecting of preliminary data there were performed a series of experimental analysis as follows: Electrical Strain Gauges (ESGs); the Moiré Fringes method; Photo-Elasticity, with the particular technique thereof, the so-called Photo-Stress method; Holographic Interferometry (HI); Speckle Pattern Interferometry (ESPI) and Shearography; and Video Image Correlation (VIC), which is also called Digital Image Correlation (DIC). By analyzing different methods, the following two methods resulted to be widely applicable, namely, ESG and DIC/VIC. The findings highlight the net advantages regarding the objective choice of these types of fixators, thereby contributing to a possible extension of these approaches for the benefit of medical surgical practice

Prosthesis doi: 10.3390/prosthesis7050125

Authors: Bakhan Ahmed Mohammed Ranj Adil Jalal

Implant placement requires a digital workflow and the use of surgical guides. However, there is divergence in the angulation length of influence and precision. Therefore, a 3D assessment is also required. This insertion study aims to evaluate the accuracy in vitro by utilizing guided templates, deviation analysis, depth, and orientation over different lengths and angles. Methods and Materials: This study comprises a total of 180 implants placed in 90 resin-printed mandibular models, divided into nine groups (a 3 × 3 factorial design, n = 20/group). A reference model was created using Real GUIDE software (version 5.3), integrating a CBCT scanner (Carestream CS 9600, Medit Corp., Seoul, Republic of Korea) and an intraoral scanner (Medit i900) (Medit Corp., Seoul, Republic of Korea). Implant planning and surgical guide design were digitally executed and printed with Mazic resin (Vericom Co., Ltd., Chuncheon, Republic of Korea). Implants were placed using Oxy Implant PSK Line (Oxy Implant, Brescia, Italy) fixtures in mannequins. Postoperative CBCT scans were used to measure deviations in angular, vertical, and lateral dimensions using CS Imaging (v8.0.22) (Carestream Dental LLC, Atlanta, GA, USA). Statistical analysis was run by using SPSS v26. Results: The results demonstrated that implant angulation significantly impacted the precision of placement. Angulating escalation leads to intensive deviations, which are linear and angular calculations. On the one hand, the most significant deviations were observed at a 25° angulation, particularly in the buccal and lingual apex regions. On the other hand, 0° exhibited minimal deviations. Longer implants showed reduced angular deviations, whereas shorter implants (8.5 mm) exhibited higher vertical deviations, particularly at 0° of angulation. Moderate angulation (15°) with 11.5 mm implants provided the highest precision, while 0° angulation with 15 mm implants consistently exhibited the least deviation. These findings pinpoint the fundamental importance of angulation and implant length for exceptional placement accuracy. Conclusions: This study demonstrates the influence of placement accuracy with static guides on implant angulation and length. Moderate angulation, which is (15°), enhances accuracy, particularly within 11.5 mm implants. On the other hand, steeper angles (25°) and longer implants (15 mm) result in elevated deviations. Guidance formation and operator experience are also vital.

Prosthesis doi: 10.3390/prosthesis7050124

Authors: Luca Baldassari Matilde Minuto Emanuele Gruppioni Mattia Frascio

This study proposes an approach to design and develop a prosthetic foot using bamboo laminate, a sustainable and cost-effective material. The proposed design method is an alternative to the current prosthetic foot design methods developed mainly for carbon-fiber reinforced polymer. This design solution entails significant economic and environmental costs. The research is structured into three main phases: an experimental campaign to characterize the reference prosthesis and select materials for the prototype; a dimensional design and prototyping phase using the new materials; and finally, a phase dedicated to testing and comparative evaluation of the results. Static tests, conducted in accordance with ISO 22675 on both the bamboo prototype and a commercial reference model, revealed comparable static performance between the two solutions. The laminated bamboo prosthetic foot exhibits a strength-to-weight ratio comparable to that of carbon fiber laminates. Its stiffness deviates by less than 15%, with an 8% reduction in weight and a 7% increase in volume compared to the carbon fiber counterpart. Therefore, these results confirm the feasibility of laminated bamboo as a viable material for prosthetic foot design.

Prosthesis doi: 10.3390/prosthesis7050123

Authors: Vladislav Demenko Igor Linetskiy Oleg Yefremov Larysa Linetska Natalia Smetankina Andrii Kondratiev

Background/Objectives: Finite element analysis (FEA) can predict biomechanical performance of dental implants in compromised bone. In the posterior maxilla, low bone density, thin cortex, and variable regenerated bone stiffness may lead to pathological peri-implant strains. This study examined the effects of implant diameter, cortical thickness, cancellous bone type, and regenerated bone elasticity on strain distribution in short plateau (Bicon SHORT®) implants. Methods: Three-dimensional FEA models of type III and IV maxillae with cortical layers of 1.0, 0.75, and 0.5 mm were developed. Implants of 4.5, 5.0, and 6.0 mm diameter were tested, with regenerated bone elasticity set to 25–100% of cortical values. An oblique load of 120.9 N at 75° was applied under full osseointegration, and first principal strains were compared with Frost’s 3000 με threshold. Results: Cortical strains remained at physiological levels, but cancellous bone in type IV often exceeded 3000 με, especially with smaller diameters and low regenerated stiffness. Enlarging implant diameter to 6.0 mm lowered cancellous maximal first principal strain by up to 56% in type III and 36% in type IV bone. Reduced regenerated bone elasticity markedly increased risk, particularly with cortical thickness < 0.75 mm. Conclusions: Biomechanical risk depends on implant diameter and regenerated bone quality. Wide short implants (6.0 mm) most effectively limited pathological strain under low cortical support and poor regenerated stiffness. Patient-specific FEA may guide implant choice and improve outcomes in atrophic maxilla rehabilitation.

Prosthesis doi: 10.3390/prosthesis7050122

Authors: Ali Sabah Mohammad Zhala Dara Omar Meran

Objective: Maxillofacial silicone elastomers represent a standard material in maxillofacial prosthetic applications due to their excellent biocompatibility and aesthetic properties. However, their long-term performance is limited by color degradation and susceptibility to fungal colonization. Incorporating nanoparticles into silicone matrices has emerged as a potential solution to enhance durability and hygiene. This study aimed to evaluate the effect of zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles used individually and in combination to evaluate the color stability and antifungal activity of pigmented maxillofacial silicone elastomers. Material and Methods: Fifty specimens were fabricated for each test and divided into five groups: Group (A) control (pigmented silicone only, no nanoparticles), Group (B) ZnO (1.5 wt%), Group (C) TiO2 (2.5 wt%), and two combinations: Group(D1) (0.75 wt% ZnO + 1.25 wt% TiO2) and Group (D2)(0.5 wt% ZnO + 0.83 wt% TiO2) ratios. Color stability was assessed before and after 500 h of artificial aging using CIELAB-ΔE values and visual scoring. Antifungal activity was evaluated against Candida albicans using the disk diffusion method. Attenuated Total Reflectance with Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning electron microscopy (SEM) along side with Energy-dispersive X-ray spectroscopy (EDS) were applied for Specimen characterization. Data were analyzed with one-way ANOVA and Tukey’s post hoc test (α = 0.05). Results: The dual-nanoparticle group with 0.75% ZnO and 1.25% TiO2 demonstrated the best color stability (ΔE = 0.86 ± 0.50) and strongest antifungal activity (inhibition zone: 7.8 ± 3.8 mm) compared to the control (ΔE = 2.31 ± 0.62; no inhibition). Single-nanoparticle groups showed moderate improvements. A significant Association (r = 0.89, p < 0.01) was found between nanoparticle dispersion and material performance. Conclusions: Incorporating ZnO and TiO2 nanoparticles into maxillofacial silicone elastomers significantly enhances color stability and antifungal efficacy. The combined formulation showed a synergistic effect, offering promising potential for improving the longevity and hygiene of maxillofacial prostheses.

Prosthesis doi: 10.3390/prosthesis7050121

Authors: Panagiotis Lampropoulos Nikitas Sykaras Jens Christoph Türp

Objective: The Staub™ Cranial system is based on defined anatomical reference points of edentulous casts that can guide the reconstruction of artificial teeth on the edentulous jaw. The aim of this study was to evaluate the validity of the Staub™ Cranial system in reconstructing the position of natural teeth in edentulous maxillae. Materials and methods: To reconstruct the original position of natural teeth, 20 fully dentate maxillary casts were produced, and 20 duplicates had all teeth eliminated. Subsequently, following the Staub™ Cranial system guidelines, an artificial teeth set-up was completed. The measured distances included the intermolar width #16–26, the intercanine width #13–23, and the incisocervical length #11. Measurements were made using the principle of stripe projection with specially developed software. Original and reproduced casts were then compared. The reproduced casts with measured distances deviating less than 5% from the mean values of control models were considered successful reconstructions. Results: The ability of the system to reconstruct the original position of lost teeth in the edentulous jaw was precise. With a narrow tolerance range of 5%, 80% of the models could be reproduced with zero or a deviation in one dimension only. Conclusions: The results of this study confirmed the efficacy of the Staub™ Cranial system to provide guidance for the customized arrangement of artificial teeth in edentulous jaws.

Prosthesis doi: 10.3390/prosthesis7050120

Authors: Teresa Pinho Maria Soeima

Objectives: This study aimed to evaluate the available evidence on the use of orthodontic mini-implants (MIs) as temporary anchorage devices (TADs), with particular focus on how insertion angulation may influence clinical outcomes. A clinical case report was also included to complement the review findings. Methods: A systematic review was performed following PRISMA guidelines and a focused PICO question. Searches in PubMed, Web of Science, and Scopus, supplemented by manual screening of reference lists. Duplicates, systematic reviews, and studies outside the PICO scope were excluded. An observational analysis of CBCT and intraoral images, and a clinical case report, were evaluated with a standardized protocol for angulation classification based on anatomical landmarks and angular measurements. Results: Ten studies met the eligibility criteria. Most reported high survival rates, with stability defined by the absence of TAD mobility or loss. CBCT-derived data from two studies, together with one clinical case, demonstrated maintenance of alveolar bone. Improved outcomes were occasionally associated with changes in insertion angulation. Vertical positioning was more frequently linked to complications in shorter TADs, while horizontal placement preserved bone but introduced hygiene-related difficulties. Conclusions: TAD success and bone preservation may depend on insertion angulation, TAD size, and soft tissue conditions. Further standardized prospective studies are needed to validate these findings, particularly regarding intermediate diagonal insertion angles (between vertical and horizontal) extending from palatal to buccal, as observed in our clinical case, which is not yet reported in the literature.

Prosthesis doi: 10.3390/prosthesis7050119

Authors: Ali A. Assiry Rawan S. Alrehaili Abdulaziz Mahnashi Hadia Alkam Roaa Mahdi Razan Hakami Reem Alshammakhy Walaa Almallahi Yomna Alhawsah Ahmed S. Khalil

Background: Artificial intelligence (AI) is influencing pediatric dentistry by supporting diagnostic accuracy, optimizing treatment planning, and improving patient care, especially for children with special needs. Previous studies explored various aspects of AI in pediatric dentistry and special care dentistry, predominantly focusing on clinical implementation or technical advancements. However, no prior review has specifically addressed its application at the intersection of pediatric dentistry and special care dentistry, particularly with respect to ethical and environmental perspectives. Objective: This scoping review provides a comprehensive synthesis of AI technologies in pediatric dentistry with a dedicated focus on children with special health care needs. It aims to critically evaluate current applications and examine the clinical, ethical, and environmental implementation challenges unique to these populations. Methods: A structured literature search was conducted in PubMed, Scopus, and Web of Science from inception to August 2025, using predefined inclusion and exclusion criteria. Eligible studies investigated AI applications in pediatric dental care or special needs contexts. Studies were synthesized narratively according to thematic domains. Results: Sixty-five studies met the inclusion criteria. Thematic synthesis identified nine domains of AI application: (1) diagnostic imaging and caries detection, (2) three-dimensional imaging, (3) interceptive and preventive orthodontics, (4) chatbots and teledentistry, (5) decision support, patient engagement and predictive analytics, (6) pain assessment and discomfort monitoring, (7) behavior management, (8) behavior modeling, and (9) ethical considerations and challenges. The majority of studies were conducted in general pediatric populations, with relatively few specifically addressing children with special health care needs. Conclusions: AI in pediatric dentistry is most developed in diagnostic imaging and caries detection, while applications in teledentistry and predictive analytics remain emerging, and areas such as pain assessment, behavior management, and behavior modelling are still exploratory. Evidence for children with special health care needs is limited and seldom validated, highlighting the need for focused research in this group. Ethical deployment of AI in pediatric dentistry requires safeguarding data privacy, minimizing algorithmic bias, preventing overtreatment, and reducing the carbon footprint of cloud-based technologies.