Search Results (216)

The increasing adoption of digital workflows in implant dentistry relies heavily on the accuracy of implant scan bodies (ISBs), which may be affected by repeated sterilization. This in vitro study evaluated the effect of 50 steam sterilization cycles on the dimensional stability of polymer and titanium ISBs. A total of 100 test specimens (n = 50 per material) were scanned before (T0) and after sterilization (T50) using a high-resolution intraoral scanner, generating 900 STL datasets for metrological analysis. Surface deviation, linear displacement, and angular deviation were assessed using validated industrial and dental software, with statistical evaluation performed through paired tests and linear mixed-effects models. Both materials exhibited statistically significant dimensional changes after sterilization (p < 0.001). Titanium scan bodies demonstrated greater linear deformation (69.76 μm) compared to polymer ones (49.50 μm), while maintaining superior angular stability (0.21° vs. −1.69° mean angular change in the polymer group). A significant interaction between material type and sterilization was observed. Despite high baseline precision, repeated autoclaving induced clinically relevant deviations in both materials. These findings indicate that cumulative sterilization cycles adversely affect ISB accuracy and highlight the importance of adhering to manufacturer recommendations to ensure optimal prosthetic outcomes. Full article

Background: Pubic symphysis plating is a common method for stabilizing traumatic pubic symphysis disruptions, yet reported rates of implant failure vary widely in the literature. This variability may reflect inconsistent definitions and failure to distinguish clinically significant early construct failure from later asymptomatic postoperative radiographic changes. Methods: We performed a retrospective observational study of 30 patients with traumatic pubic symphysis disruption without associated fractures of the pubic body or pubic rami treated with open reduction and plate fixation. Pubic symphysis distance (PSD) was measured on admission CT, immediate postoperative anteroposterior pelvic radiographs, and follow-up CT scans obtained at 3, 6, and ≥12 months. Early mechanical failure, qualitative radiographic signs of implant loosening, and radiographic loss of reduction were predefined. Non-parametric tests were used to compare patients with and without early mechanical failure and to evaluate longitudinal PSD changes; analyses of potential associated factors were exploratory. Results: Early mechanical failure occurred in 4 patients (13.3%) within 30 days and presented as an acute symptomatic event with imaging-confirmed construct compromise requiring revision. In exploratory univariable analysis, early failure was more frequent in female patients and in those with obesity or osteoporosis, although these findings should be interpreted cautiously given the very small number of events. PSD changed significantly over time (p < 0.001), with minimal increase during the first 3 months, greater widening between 3 and 6 months, and little additional change thereafter. Qualitative radiographic signs of implant loosening and widening were observed in 8 patients (26.7%) during follow-up without clinically documented pain, instability, or need for revision. No clear association was demonstrated between PSD widening and final functional outcome measured by the Majeed score, although these analyses were limited by sample size and wide confidence intervals. Conclusions: In this retrospective cohort, postoperative radiographic widening and qualitative signs of implant loosening were not by themselves associated with clinically evident failure requiring revision during the available follow-up. Early failure was identified by acute clinical symptoms with imaging-confirmed construct compromise, whereas delayed widening was often observed without clinically documented pain, instability, or reoperation. These findings suggest that postoperative imaging should be interpreted together with symptoms and overall pelvic stability, while recognizing the methodological limitations of the study. Full article

Background: Magnetic Particle Imaging (MPI) is an emerging biomedical imaging modality that detects superparamagnetic iron oxide nanoparticles (SPIONs), providing high contrast, sensitivity, and quantification capabilities without ionizing radiation, making it particularly suitable for cancer diagnostics. Considerable engineering efforts are underway to translate MPI technology to clinical settings. Most of these MPI scanners feature a cylindrical bore geometry similar to that of other clinical imaging modalities, which limits their potential application primarily to head scanning. Methods: We have developed a single-sided MPI scanner designed to expand the modality’s applicability to other regions of the human body through a unique hardware design developed in our previous work. Imaging experiments were performed on an anatomical breast phantom containing implanted SPION point sources placed at anatomically plausible locations for breast tumors. These point sources served as artificial tumors for evaluating the system’s suitability for breast imaging applications. Results: The scanner successfully detected and clearly resolved the implanted SPION tumors in two orthogonal imaging planes. Tumor positioning was independently validated by ultrasound imaging, confirming MPI’s accurate localization. In addition, sensitivity measurements demonstrated a detection limit of 4.0 $\mathsf{\mu }\mathrm{g}$ of iron, below the estimated 4.8 $\mathsf{\mu }\mathrm{g}$ sensitivity threshold required for breast tumor detection with electronic depth scanning up to 3.5 cm deep. Conclusions: Together, these results demonstrate the capability of a single-sided MPI geometry for breast imaging applications. Imaging an anatomical breast-shaped volume presents significant challenges for MPI due to the size and accessibility constraints of conventional hardware. The results presented highlight the advantages of this approach and support its potential to extend MPI from small-animal imaging to clinically relevant applications. Full article

With increasing life expectancy and an aging global population, the demand for orthopedic and dental implants is increasing. Recently developed, citric-acid-based anodization processes facilitate the production of more bioactive oxide layers by incorporating important bone minerals such as Ca, P, and Mg and forming bone-like crystalline compounds such as carbonated apatite on titanium implant materials. The primary goal of the present study was to evaluate the applicability of these anodization processes to solid and 3D-printed titanium alloy substrates. The anodized oxides produced on each solid or 3D-printed lattice substrate revealed multi-scaled surface roughness profiles as evidenced by scanning electron microscopy, optical microscopy, and surface roughness analyses. Additionally, each oxide group was shown to incorporate substantial amounts of Ca, P, and Mg bone-mineral dopants and form AB-type carbonated apatite, as shown using a combination of energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and attenuated total reflectance–Fourier transform infrared spectroscopy analyses. Finally, each oxide group showed sustained Ca, P, and Mg ion release during an inductively coupled plasma spectroscopy dissolution assessment, and demonstrated early apatite-forming ability during simulated body fluid bioactivity testing. The findings of this study show much promise for the applicability of these novel oxide coatings to a wide variety of future titanium implant applications. Full article

Background: Accurate digital impressions are crucial for the long-term success of implant-supported prostheses, with scan bodies playing a pivotal role in transferring the implant position into the virtual model. Recent work has focused on PEEK (polyether-etherketone) scan bodies because their optical behavior may facilitate intraoral scanning; however, the breadth and quality of supporting evidence remain unclear. Methods: This scoping review followed PRISMA-ScR reporting guidelines and was registered in the Open Science Framework (OSF; Registration DOI 10.17605/OSF.IO/CU3V8). Pub-Med/MEDLINE, Embase, and Scopus were searched through September 2025. Eligible designs included in vitro studies, randomized trials, observational studies, and technical reports evaluating PEEK scan bodies in implant dentistry. Screening and data extraction were performed in duplicate, and findings were synthesized descriptively. Results: The search identified 227 records, and after screening, 31 studies met the inclusion criteria. Most studies were in vitro, with limited clinical evidence, and only one prospective clinical study was identified. Outcomes commonly addressed trueness, precision, scan time, and handling. Comparators varied (e.g., titanium, resin; splinted vs. unsplinted), and the results on accuracy were heterogeneous, with deviations typically within clinically acceptable limits (<100 µm). Conclusions: PEEK scan bodies are applicable for digital implant impressions. Clinical data are sparse, though, and methods vary. Controlled clinical studies are necessary to confirm the accuracy, reliability, and indications of this approach compared to titanium ISBs. Full article

Background/Objectives: Atraumatic electrode array insertion should be targeted in cochlear implantation. Robotic insertion is used in many centers worldwide. Our objective was to evaluate manual electrode placement and robot-assisted placement using RobOtol^® on human temporal bones (TBs), in terms of endocochlear trauma and completion of insertion. Methods: Sixteen TBs originating from eight bodies were implanted with Medel-FLEX24 electrodes through the round window. The right TB was implanted manually, while the left TB of the same body was implanted using RobOtol^® for electrode insertion. Results were analyzed through micro-computed tomography imaging. No statistical analysis was used, given the small sample size; a descriptive interpretation of micro-CT scans was rather preferred. Results: In the “manual group”, there were two cases (25%) of insertion trauma: elevation of basilar membrane at basal turn (Eshraghi-stage-1). In the “robotic group”, there were two cases (25%) of insertion trauma: one case of elevation of basilar membrane at the middle turn (Eshraghi-stage-1) and one case of dislocation of all electrodes in scala vestibuli (Eshraghi-stage-3). There were six cases (75%) of incomplete insertion in the “manual group” and four cases (50%) of incomplete insertion in the “robotic group”. Conclusions: Both techniques of electrode placement yielded fairly similar results, in terms of endocochlear trauma and completion of insertion. New larger-scale cadaveric and clinical studies are needed to determine the possible benefit of robot-assisted electrode insertion in cochlear implantation. Full article

Titanium alloys, particularly β-type Ti-13Nb-13Zr, are promising biomedical materials due to their low elastic modulus and excellent biocompatibility. However, their bioactivity needs improvement for better bone integration. In this study, a calcium-phosphate (Ca/P) coating was prepared on a Ti-13Nb-13Zr alloy via micro-arc oxidation (MAO) in an electrolyte containing calcium acetate and dipotassium hydrogen phosphate. The effect of applied voltage (300 V, 400 V, and 500 V) on the phase composition, surface morphology, and in vitro bioactivity of the coatings was investigated. Surface characterization was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS). The results show that increasing the voltage increased the surface roughness, average pore size, and rutile TiO₂ content in the coating. The Ca/P ratio in the coating approached 1.67 at 500 V, similar to that of natural bone. After immersion in simulated body fluid (SBF) for 20 days, the coating formed at 500 V induced the highest deposition of hydroxyapatite (HA), completely covering the microporous surface. These findings indicate that MAO treatment at 500 V significantly enhances the bioactivity of the Ti-13Nb-13Zr alloy, making it a promising candidate for orthopedic implants. Full article

The accuracy of digital impressions in fully edentulous cases is limited by the lack of anatomical reference structures, potentially affecting passive fit. The effects of scanner type, impression level, and scan body splinting on accuracy remain insufficiently elucidated. This in vitro study aimed to evaluate the effects of different intraoral scanners, scanning levels, and scan body splinting methods on digital impression accuracy. A fully edentulous mandibular model with four implants (All-on-4) was fabricated, and scan bodies were connected at either the implant or multi-unit abutment level. Five splinting methods (nonsplinted, floss, orthodontic elastomeric, chain attachments, and single attachments) were applied, creating 10 experimental groups. Each group was scanned using three intraoral scanners: iTero Lumina (Align Technology, Tempe, AZ, USA), TRIOS 3 (3Shape A/S, Copenhagen, Denmark), and Medit i700 (Medit Corp, Seoul, Republic of Korea), with four repeated scans per scanner (120 scans total). Trueness and precision were assessed based on linear and angular deviations using Geomagic Control X (3D Systems, Rock Hill, SC, USA). Scanner type and scanning level significantly affected accuracy (p < 0.05), with TRIOS 3 showing higher deviations, while multi-unit abutments reduced deviations. Splinting methods showed no significant effect on accuracy, and precision did not differ among groups. Scanner type and scanning level significantly influenced digital impression accuracy; however, splinting methods yielded no significant effect. Precision remained comparable among groups. Full article

The microstructure and ultrastructure of the sperm of Japanese eel, Anguilla japonica, artificially induced with weekly injections with carp pituitary (CP) and human chorionic gonadotropin (HCG), was studied, and milt from 10 out of 20 mature fish was collected. Two distinct morphological structures of A. japonica sperm had been observed with optical microscopy. The cell nucleus of one type of sperm was round or nearly round, the sperm was smaller in size, with 2.57 ± 0.62 μm of the long diameter of the cell nucleus, 2.11 ± 0.59 μm of the short diameter, and 37.35 ± 7.71 μm of the flagellum length. Another type was the eyebrow-shaped sperm, the sperm was relatively larger in size, with 7.66 ± 1.09 μm of the long axis, 2.54 ± 0.46 μm of the short axis, and 38.26 ± 9.02 μm of the flagellum length. By means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the anterior end of the round sperm lacked an acrosomal structure. The implantation fossa was located in the center of the base of the sperm head, and it was in the shape of a channel along the long axis of sperm. The centriolar complex was situated within the implantation fossa. There were 2–3 mitochondria distributed at the basal end of the nucleus. Sperm flagellum prolongated from the sleeve cavity, and the initial part of axoneme connected to the distal end of basal body. The axoneme displayed a typical “9 + 2” pattern. There was a spherical structure in the curving area for eyebrow-shaped sperm, and the axoneme formed a “9 + 0” pattern. The discovery of two different types of sperm in the Japanese eel has provided new perspectives for research on its artificial reproduction. Full article

Background: Digital technologies, particularly CAD/CAM workflows, have transformed implant prosthodontics by improving the accuracy and efficiency of impression procedures, facilitating clinician–laboratory communication, and supporting the preservation of peri-implant tissues. Objective: To compare the three-dimensional accuracy (trueness) and passive fit of five conventional and digital impression techniques for fixed prostheses supported by two implants. Methods: An in vitro experimental study was conducted using a partially edentulous maxillary model with two implants supporting a three-unit zirconia bridge. Five impression workflows were evaluated: conventional techniques (open-tray and closed-tray, splinted and non-splinted) and digital impressions using plastic and titanium scan bodies. Three-dimensional accuracy was assessed by digital superimposition analysis, and passive fit was evaluated by marginal gap measurements using digital microscopy and ImageJ (version 1.54r) software. Statistical analyses were performed using exploratory ANOVA with Welch’s correction and Games–Howell post hoc tests (p < 0.05), complemented by effect size analysis. Results: Three-dimensional superimposition analysis revealed that digital impression workflows and the splinted conventional open-tray technique exhibited the highest trueness, with minimal spatial deviations relative to the reference model, together with the lowest marginal gap values (<1 µm). The non-splinted open-tray technique presented higher discrepancies (7.37 ± 0.94 µm), although all techniques remained within clinically acceptable tolerance ranges (60–150 µm). Conclusions: Under controlled in vitro conditions, both digital impression techniques and conventional splinted protocols achieve high three-dimensional accuracy and clinically acceptable passive fit for multi-implant-supported fixed prostheses. Digital workflows represent a predictable and efficient alternative, while conventional splinted impressions remain a reliable option depending on clinical and technological considerations. Full article

Despite the widespread adoption of digital technologies in modern implant dentistry, a comprehensive synthesis of error propagation across the entire workflow of full-arch implant rehabilitation remains absent. This narrative review aimed to synthesize current evidence on cumulative error propagation throughout the digital workflow of full-arch implant rehabilitation. Rather than focusing on isolated accuracy metrics, this article proposes a conceptual “Error Control Framework” to elucidate how minor deviations introduced at different workflow stages interact and amplify. A comprehensive literature search (2015–2025) was conducted to analyze error generation across five interrelated phases: Planning, Acquisition, Processing, Output, and Feedback. The evidence indicates that inaccuracies in full-arch implant rehabilitation behave as a cascading system (snowball effect) rather than isolated events. Errors introduced during early stages establish an irreversible baseline that is magnified during digital processing and manufacturing. Consequently, reactive verification at delivery alone is insufficient. To address this, this article proposes a proactive Error Control Framework that integrates a “Front-End Loading” strategy (necessitating strict upstream standardization of scanning strategies and scan-body geometry), alongside “Critical Control Points” (enforcing mandatory physical verification prior to final manufacturing). Viewing digital full-arch rehabilitation as a cumulative error system allows clinicians to implement preventive strategies and verification checkpoints, improving passive fit and long-term mechanical and biological outcomes. Full article

Background: Digital implant impressions using intraoral scanners are increasingly adopted; however, their accuracy remains challenging in complete-arch and extended edentulous scenarios due to limited anatomical reference points and cumulative stitching errors. Various splinting techniques, scan-body modifications, and auxiliary geometric devices have been proposed to enhance digital accuracy, yet the available evidence is highly heterogeneous and lacks comprehensive synthesis. Methods: This scoping review was conducted according to PRISMA-ScR guidelines. A systematic search of PubMed/MEDLINE, Embase, Scopus, and Web of Science databases identified studies evaluating materials, designs, or techniques intended to splint, stabilize, or geometrically augment intraoral scan bodies in digital implant workflows. In vitro, clinical, and mixed-design studies were included. Data were extracted descriptively and synthesized narratively. Results: Seventy-three studies met the inclusion criteria, the majority of which were in vitro investigations focused on fully edentulous arches. Splinting strategies included direct resin-based connections, rigid or semi-rigid auxiliary geometric devices, modified scan bodies with extensional geometries, and artificial landmarks. Most studies reported improved trueness, precision, or scanning efficiency when rigid or geometrically enriched devices were used, particularly in long-span or angulated implant configurations. However, flexible or optically interfering splints occasionally reduced accuracy, and outcomes were strongly scanner-dependent. Conclusions: Splinting and auxiliary scanning strategies generally enhance the accuracy of complete-arch digital implant impressions, especially when rigid, well-engineered, or geometrically complex designs are employed. Modified scan bodies and calibrated auxiliary devices appear particularly promising, while flexible splints may be counterproductive. Standardized protocols and further in vivo validation are required to optimize digital implant workflows. Full article

Background/Objectives: Intraoral scanners (IOSs) are essential tools in digital dentistry; however, their accuracy remains influenced by clinical conditions such as restricted access, patient movement, or intraoral moisture. Intraoral scanning is performed within a confined space that restricts scanner motion, potentially influencing maneuverability during data acquisition and, consequently, IOS performance. This study investigated the impact of maneuverability constraints on the trueness accuracy and efficiency of IOS under clinically representative intraoral conditions. Methods: Fifteen participants with no previous experience in intraoral scanning or device operation were recruited. Each participant scanned a maxillary full-dentition typodont model and a mandibular implant-containing typodont model using the Aoralscan 3 IOS. Scans were performed under two conditions: constrained intraoral scanning within a manikin and open-vision extraoral scanning on a bench-top. Trueness accuracy was evaluated using three parameters: the root mean square (RMS) deviation of the maxillary dentition, discrepancies in inter–scan body distances, and angular deviations of the scan bodies, each calculated by comparison with reference data obtained from an industrial-grade scanner. Scan time was recorded to assess time-based efficiency. Results: No significant differences were observed in RMS trueness, inter-implant distances, or implant angular deviations between intraoral and extraoral scans. Extraoral scanning significantly reduced scan times for both maxillary and mandibular models (p < 0.0001). Conclusions: Within the limitations of this study, maneuverability constraints alone may not significantly affect IOS trueness accuracy compared with open bench-top scanning. However, scanning efficiency was reduced under intraoral scanning constraints, with longer scan times observed among inexperienced operators. The potential influence of intraoral factors other than maneuverability on IOS accuracy under clinical conditions warrants further investigation. Full article

Background: Computer-guided static implant surgery (CGSIS) is widely adopted to enhance the precision of dental implant placement. However, significant heterogeneity in reported accuracy values complicates evidence-based clinical decision-making. This variance is likely attributable to a fundamental lack of standardization in the methodologies used to assess dimensional accuracy. Objective: This scoping review aimed to systematically map, synthesize, and analyze the clinical methodologies used to quantify the dimensional accuracy of CGSIS. Methods: The review was conducted in accordance with the PRISMA-ScR guidelines. A systematic search of PubMed/MEDLINE, Scopus, and Embase was performed from inception to October 2025. Clinical studies quantitatively comparing planned versus achieved implant positions in human patients were included. Data were charted on study design, guide support type, data acquisition methods, reference systems for superimposition, measurement software, and accuracy metrics. Results: The analysis of 21 included studies revealed extensive methodological heterogeneity. Key findings included the predominant use of two distinct reference systems: post-operative CBCT (n = 12) and intraoral scanning with scan bodies (n = 6). A variety of proprietary and third-party software packages (e.g., coDiagnostiX, Geomagic, Mimics) were employed for superimposition, utilizing different alignment algorithms. Critically, this heterogeneity in measurement approach directly manifests in widely varying reported values for core accuracy metrics. In addition, the definitions and reporting of core accuracy metrics—specifically global coronal deviation (range of reported means: 0.55–1.70 mm), global apical deviation (0.76–2.50 mm), and angular deviation (2.11–7.14°)—were inconsistent. For example, these metrics were also reported using different statistical summaries (e.g., means with standard deviations or medians with interquartile ranges). Conclusions: The comparability and synthesis of evidence on CGSIS accuracy are significantly limited by non-standardized measurement approaches. The reported ranges of deviation values are a direct consequence of this methodological heterogeneity, not a comparison of implant system performance. Our findings highlight an urgent need for a consensus-based minimum reporting standard for future clinical research in this field to ensure reliable and translatable evidence. Full article

Aim: This study evaluates the digital accuracy of posterior implant scans and contralateral molar tooth scans obtained with three different intraoral scanners. Materials and Methods: Using a transfer analog, a Frasaco maxillary model was prepared with a Megagen scan body positioned in the left maxillary molar region. An experienced operator (n = 10) performed all scans with an industrial optical reference scanner and intraoral scanners (Medit i700, TRIOS 3, and TRIOS 5). Scan accuracy was assessed using Geomagic Control X software based on 3D trueness and precision accuracy analysis. One-way ANOVA and Tukey’s HSD tests were applied to identify statistically significant differences in trueness and precision (α = 0.05). Results: In the implant region, TRIOS 5 demonstrated significantly different 3D trueness results and was more successful than TRIOS 3. Medit i700 yielded results comparable to those of TRIOS 3 and TRIOS 5 (p = 0.011). TRIOS 5 exhibited less successful 3D trueness results than the other scanners in the molar region (p = 0.001). No 3D precision differences were observed among intraoral scanners in the implant region (p = 0.561). Medit i700 presented the most favorable precision results in the molar region (p = 0.01). Conclusions: TRIOS 5 supports high impression accuracy and passive fit, while Medit i700 offers more reliable accuracy for contralateral molar scans, which can affect the digital occlusal record. Full article