Search Results (2,115)

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. Full article

Background/Objectives: Total hip arthroplasty (THA) is a widely accepted and effective intervention for advanced degenerative hip disease. However, prosthetic dislocation remains one of the most common postoperative complications. This study aimed to evaluate the biomechanical consequences of implant positioning variations and their influence on prosthetic stability. Methods: A three-dimensional finite element model (FEM) of the pelvis and hip joint was developed using SolidWorks Professional 2025, based on CT imaging of an anatomically normal adult. Multiple implant configurations were simulated, varying acetabular cup inclination and anteversion angles, femoral stem depth, and femoral offset. Muscle force vectors replicating single-leg stance conditions were applied according to biomechanical reference data. The mechanical performance of each configuration was quantified using the safety factor (SF), defined as the ratio of allowable material stress to calculated stress in the model. Results: The configuration with 45° cup inclination, 15° anteversion, standard femoral offset, and optimal stem depth demonstrated the highest SF values (9–12), indicating a low risk of mechanical failure or dislocation. In contrast, malpositioned implants—particularly those with low or high anteversion, excessive offset, or shallow stem insertion—resulted in a marked decrease in SF values (2–5), especially in the anterosuperior and posterosuperior quadrants of the acetabular interface. Conclusions: The findings underscore the critical importance of precise implant alignment in THA. Even moderate deviations from optimal positioning can substantially compromise biomechanical stability and increase the risk of dislocation. These results support the need for individualized preoperative planning and the use of assistive technologies during surgery to enhance implant placement accuracy and improve clinical outcomes. Full article

This study aimed to evaluate the impact of different adhesive solutions on the surface roughness and hardness of denture base materials. Twenty specimens (20 × 20 × 5 mm) were produced for each material group: heat-cured ProBase Hot^®, 3D-printed NextDent Denture 3D+^®, and PMMA-milled Exaktus^®. They were then divided into five solution subgroups (n = 4): control (T0), distilled water, Corega PowerMax^®, Elgydium Fix^®, and Kukident Pro Ultimate^®. Specimens were immersed in the solution at 37 °C daily for 28 days, simulating continuous use. Profilometry and Shore D hardness tests were performed at baseline and after 28 days of the immersion protocol. Data analysis was done using IBM SPSS Statistics 30.0, considering a confidence level of 0.05. At baseline, the materials differed in surface roughness and Shore D hardness, with the 3D-printed group showing the highest median values for the Rz parameter (p = 0.023) and the lowest for hardness (p = 0.023). Elgydium Fix had a significant effect on the heat-cured resin, with increased Rz and decreased hardness. Kukident caused higher roughness and lower hardness in the 3D-printed and milled resins (not significant). Corega showed minor effects in all tested materials. In conclusion, the denture base material and the adhesive formulation influence the physical and mechanical properties of denture base resins. Full article

Introduction: Neck-preserving total hip arthroplasty (THA) has gained interest for conserving bone stock, restoring biomechanics, and facilitating revision surgery. The Nanos^® femoral stem, designed for metaphyseal fixation while preserving the femoral neck, represents a reliable alternative to conventional THA. This study reports 15-year clinical and radiographic outcomes of the Nanos implant. Materials and Methods: We retrospectively reviewed 53 patients (35 males, 18 females) who underwent THA with the Nanos stem between 2008 and 2010. Patients were stratified into two groups according to age: <50 years (n = 24) and ≥50 years (n = 29). The primary diagnosis was osteoarthritis (95%), with a few cases of avascular necrosis or dysplasia. Clinical evaluation included the Harris Hip Score (HHS) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Radiographic assessment focused on implant stability, osteolysis, and heterotopic ossifications. Kaplan–Meier survival analysis was performed with revision for any reason as the endpoint. Results: At 15 years of follow-up, both groups showed significant improvement (p < 0.001). In patients <50 years, HHS increased from 53.3 to 94.8 and WOMAC decreased from 79.9 to 3.5. In patients ≥50 years, HHS improved from 47.5 to 95.2 and WOMAC from 81.5 to 3.2. Radiographs confirmed stable fixation without osteolysis. Complications included two dislocations and one cortical perforation requiring revision. Kaplan–Meier survivorship at 15 years was 100% (<50) and 96.6% (≥50). Conclusions: The Nanos stem provided excellent long-term outcomes with low complication and revision rates. It should be considered one of several reliable short-stem options for younger, active patients, offering durable function while preserving bone stock. Full article

This work aimed to quantify axial deformations of a human premolar during occlusion with its antagonist and to compare them with the same premolar restored with a ceramic crown. The deformations were put under stress using a mechanical press with a force ranging from 1 to 100 Newtons. These deformations were quantified using the optical interferometry technique with a laser source (633 nm, 0.95 mW). Using a CMOS camera, interference fringes were obtained, stored, and subsequently processed. The premolars were restored with Cerasmart GC ceramic, using the CAD-CAM system. The average deformations of healthy premolars were found to be in a range of 0.69 to 1.74 µm, while the restored ones were deformed in a range of 0.53 to 1.10 µm. The results of this work showed that the Cerasmart ceramic material had similar properties to those of the natural tooth for small forces. However, for higher forces, the ceramics increased the coronal stiffness of the tooth. This modified the optimal combination of stiffness, strength, and resilience between the enamel and dentin, causing a decrease in the tooth’s ability to dissipate energy; therefore, the tooth could receive more stress. The observed mechanical properties lead to the conclusion that the Cerasmart material can be indicated for the restoration of anterior and premolar teeth in most cases where a fixed prosthesis is required. Full article

Background: The implant–abutment interface has been thoroughly examined due to its impact on the success of implant healing and longevity. Removing the abutment is advantageous, but it changes the biomechanics of the implant fixture and restoration. This in vitro three-dimensional finite element analytical (FEA) study aims to evaluate the distribution of von Mises stress (VMS) in abutment-free and three additional implant abutment connections composed of various titanium alloys. Materials and methods: A three-dimensional implant-supported single-crown prosthesis model was digitally generated on the mandibular section using a combination of microcomputed tomography imaging (microCT), a computer-assisted designing (CAD) program (SolidWorks), Analysis of Systems (ANSYS), and a 3D digital scan (Visual Computing Lab). Four digital models [A (BioHorizons), B (Straumann AG), C abutment-free (Matrix), and D (TRI)] representing three different functional biomaterials [wrought Ti-6Al-4Va ELI, Roxolid (85% Ti, 15% Zr), and Ti-6Al-4V ELI] were subjected to simulated static/cyclic static loading in axial/oblique directions after being restored with highly translucent monolithic zirconia restoration. The stresses generated on the implant fixture, abutment, crown, screw, cortical, and cancellous bones were measured. Results: The highest VMSs were generated by the abutment-free (Model C, Matrix) implant system on the implant fixture [static (32.36 Mpa), cyclic static (83.34 Mpa)], screw [static (16.85 Mpa), cyclic static (30.33 Mpa), oblique (57.46 Mpa)], and cortical bone [static (26.55), cyclic static (108.99 Mpa), oblique (47.8 Mpa)]. The lowest VMSs in the implant fixture, abutment, screw, and crown were associated with the binary alloy Roxolid [83–87% Ti and 13–17% Zr]. Conclusions: Abutment-free implant systems generate twice the stress on cortical bone than other abutment implant systems while producing the highest stresses on the fixture and screw, therefore demanding further clinical investigations. Roxolid, a binary alloy of titanium and zirconia, showed the least overall stresses in different loadings and directions. Full article

Background: Total hip arthroplasty (THA) is a common procedure, yet instability and dislocation remain leading causes of revision. Dual mobility (DM) acetabular constructs improve stability, but comparative data across modular DM systems are limited. This study compared the safety and efficacy of three modular DM implants in primary THA, focusing on acetabular revision and functional recovery. Methods: We retrospectively reviewed 963 primary THAs performed from 2016–2024 using three modular DM systems. Patients with revision or bilateral THA, age < 18, or <2 years of follow-up were excluded. Outcomes included acetabular revision, 90-day readmission, and Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS, JR). Kaplan–Meier analysis estimated 3-year implant survivorship for each implant, and non-inferiority of Implant A was tested against a combined “Dual Mobility Control” cohort (Implants B + C) using a prespecified −10% margin. Results: A total of 297 patients met inclusion criteria (142 Implant A, 110 Implant B, 45 Implant C). Revision rates were 4.9% for Implant A, 6.4% for Implant B, and 8.9% for Implant C. HOOS, JR scores improved significantly in all cohorts with comparable 2-year outcomes. Kaplan–Meier analysis showed 3-year survivorship of 98.3% for Implant A, 98.4% for Implant B, and 96.9% for Implant C (log-rank p = 0.053). The Dual Mobility Control cohort survivorship was 98.0%, and the difference between Implant A and controls (95% CI: −2.19% to 2.69%) met the non-inferiority margin (log-rank p = 0.796). Conclusions: Implant A demonstrated non-inferior 3-year survivorship and comparable short-term patient-reported outcomes relative to two other modular DM implants. Larger, multicenter studies with longer follow-up are warranted to confirm these findings. Full article

Background: Lower limb amputation (LLA), due to non-traumatic causes such as vascular diseases and diabetes, significantly impacts patients’ physical, psychological, and social well-being. While multidisciplinary rehabilitation programs commonly address physical and functional recovery, psychological and subjective experiences related to limb loss remain less explored. Thus, this preliminary study aimed to investigate the psychological and behavioral adaptation processes in patients undergoing rehabilitation following lower limb amputation. Methods: A preliminary observational study with a mixed-method approach based on quantitative and qualitative data triangulation was conducted. This approach involves integrating multiple data sources and methodologies—in this case, quantitative psychometric measures and qualitative interviews via the prospective of amputees and those who use prostheses—to enhance the validity and depth of the research findings. Results: Fourteen inpatient amputees and fourteen inpatient prosthesis users (years: 66.6 ± 2.5 for amputee and 61.5 ± 1.9 for prosthesis users, male amputees: 85.7%, male prosthesis users: 100%) of a research hospital in the North of Italy were assessed using validated psychometric tools (GAD-7, PHQ-9, PID-5-BF, BIS, ASonA) alongside semi-structured interviews analyzed through the Interpretive Description approach. Key themes highlighted illness acceptance, prosthesis adaptation, body image, medication and behavioral adherence, anxiety, depression, quality of life, denial, optimism, and social support. Overall, anxiety–depressive symptomatology tended to decrease with the prosthesis, and pharmacological and behavioral adherence improved, as did the disease acceptance. Body image was fairly preserved in all patients despite some fears of others’ judgment with respect to the prosthesis. Interestingly, there was poor agreement between quantitative and qualitative data in both the amputee’ and prosthesis users’ groups: while the former returned a partial and neutral picture, a more multifaceted picture emerged from the interviews collected. Conclusions: These findings underline the importance of integrating quantitative psychometric evaluations with qualitative methods to comprehensively understand patients’ adaptive experiences. Such combined insights are essential to inform tailored psychological interventions throughout the rehabilitation journey. Full article

This study investigates the mechanical properties of titanium (Titanflex®) and cobalt-chromium (Co-Cr) alloys for potential use in removable denture bases. Titanium alloys have gained attention due to their biocompatibility and regulatory concerns surrounding Co-Cr, which has been classified as a carcinogenic, mutagenic, and toxic to reproduction (CMR) substance under EU MDR (2017/745). Using selective laser melting (SLM), test specimens of Titanflex® and Co-Cr alloys were 3D-printed at different angles (0°, 45°, 90°) and compared to conventionally cast Co-Cr samples. Tensile testing was conducted to assess modulus of elasticity (E), proof stress (Rp_0.2), ultimate tensile strength (Rm), elongation parameters (Ag, Agt, At), and maximum load (Fm). Results showed that Titanflex® printed at 45° (Ti45) exhibited the highest Rp_0.2, Rm, and Fm, indicating superior strength and plastic resistance. Ti0 displayed the greatest elongation properties, highlighting titanium’s ductility. Co-Cr alloys demonstrated higher stiffness but lower ductility. Printing orientation significantly influenced mechanical properties, particularly in 3D-printed samples. Overall, Ti45 presented a balanced profile of strength and flexibility, making it a promising candidate for denture bases, while Co-Cr remains a rigid alternative with established clinical use. Future research should explore long-term performance under functional and biological conditions to guide clinical application. Full article

Background/Objectives: Our study aimed to evaluate the oral health status associated with levels of certain inflammatory biomarkers in the gingival crevicular fluid (GCF) and plasma of children and adolescents with leukemia, in comparison to healthy subjects, in order to assess the correlation between pediatric leukemia and gingivo-periodontal alterations. Methods: The study was conducted on 97 subjects, divided into two groups: the study group, n = 47 leukemia subjects, and the control group, n = 50 healthy subjects. The collected GCF and plasma samples were analyzed for interleukins IL-1β, IL-6 and IL-17α and transforming growth factor TGF-β1 values using ELISA (enzyme-linked immunosorbent assay) techniques. Results: IL-6, IL-17α, and TGF-β1 recorded higher values for leukemia subjects, both in the GCF and plasma, compared to healthy subjects. Our results also pointed out higher gingival fluid IL-1β values in children with leukemia compared to the control group. Conclusions: Elevated expressions of IL-1β in the GCF and IL-6, IL-17α, and TGF-β1, both systemic and local, in the GCF of children with leukemia were associated with oral hygiene status and gingival inflammation, respectively. All inflammatory biomarkers generally tended to rise in close correlation with oral hygiene worsening and gingival inflammation extension; however, IL-1β in the GCF and plasma, plasma IL-6, and gingival fluid IL-17α pointed out a stronger correlation with gingival inflammation status. Full article

Prophylactic measures and treatment strategies of implant-related bone and joint infections frequently involve the local delivery of high doses of antimicrobial drugs into the affected bone tissue or articular space in addition to the use of systemic antibiotics. Antibiotic-loaded biomaterials, such as Polymethyl Methacrylate (PMMA) cement, calcium sulfate, calcium phosphate, bioglass, and others, have proven to be clinically effective. However, they suffer from important limitations regarding elution and freedom of choice of admixable antimicrobial drugs. In order to overcome these shortcomings, the techniques of direct intraosseous or intra-articular injection/infusion of antibiotics via needles/cannulas or catheters are gaining popularity. Their attractiveness is based on the potential to achieve extremely high drug concentrations in situ, which can be maintained for as long as the catheters are left in place without increased risks of systemic toxicity. Although these methods are still in an experimental stage, reports on their clinical outcomes look promising. This articles summarizes the knowledge of when, how, and in which clinical settings the different modes and philosophies of local antibiotic delivery work best, with the aim to provide surgeons and infectious disease physicians guidance in clinical practice. This will help to optimize the use for the sake of the patients. Full article

Although most commonly diagnosed in the elderly population, aortic stenosis can affect younger patients, being the most frequent valvular disease requiring replacement interventions, either through surgical procedures (SAVR = surgical aortic valve replacement) or through transcatheter aortic valve implantation (TAVI). In young patients, aortic stenosis generally occurs due to congenital malformations, such as bicuspid aortic valves (BAVs), or to rheumatic valve disease, both of which present specific anatomical characteristics. There is an upward trend among young patients regarding TAVI, due to the possibility of avoiding the complications of open-heart surgery while offering a faster recovery, although it is important to note that complications, such as conduction disturbances, paravalvular leaks (PVL), or strokes, can arise. Because of the current lack of long-term data, the implications of these complications among young patients are not well established. Moreover, an important issue among young patients is the durability of the prosthesis, as patient survival is expected to exceed the device’s lifespan. The purpose of this review is to assess the current data on the most common causes of aortic stenosis and outcomes of TAVI in young patients, focusing on subgroups of patients with bicuspid aortic stenosis or rheumatic aortic stenosis, while emphasizing the potential complications, the durability of the aortic prosthesis, and reintervention possibilities. Full article

Background and Objectives: Periprosthetic joint infection (PJI) is one of the most serious complications following total joint arthroplasty (TJA), leading to poor functional outcomes and increased healthcare burden. Intraosseous (IO) regional antibiotic prophylaxis has emerged as a promising method for infection prevention, offering potential advantages over conventional intravenous (IV) systemic administration. This study aimed to systematically evaluate the clinical evidence on the efficacy and safety of IO prophylaxis in TJA. Materials and Methods: A comprehensive literature search was conducted in PubMed, Embase, Scopus, Web of Science, and the Cochrane Library up to 23 June 2025. Eligible studies included randomized controlled trials and observational studies reporting outcomes of IO antibiotic administration in TJA. Primary endpoints were systemic and local antibiotic concentrations (bone and fat tissue), the incidence of PJI, and complication profiles. Risk of bias was assessed using the ROB-2 and ROBINS-I tools, and meta-analyses were conducted using RevMan v 7.2.0. Results: Fifteen studies (eight RCTs, one prospective study, and six retrospective studies) were included for qualitative synthesis, of which ten were included in the meta-analysis. As compared with IV, IO administration resulted in significantly higher local antibiotic concentrations in bone (MD: 15.52 μg/g; 95% CI: 8.60–22.45; p < 0.0001) and fat tissue (MD: 18.15 μg/g; 95% CI: 12.86–23.45; p < 0.0001). IO prophylaxis was associated with a significantly lower PJI rate (OR: 0.26; 95% CI: 0.12–0.57; p = 0.008) without a significant difference in the incidence of complications (p = 0.66). Conclusions: IO antibiotic prophylaxis is an effective and safe strategy for infection prevention in total joint arthroplasty. By achieving superior local antibiotic concentrations and reducing PJI rates without increasing complications, this approach holds promise for broader clinical application. Full article

Background/Objectives: Conductive hearing loss (CHL) recurrence or persistence after stapes surgery is often due to prosthesis displacement or malfunction, with malleus fixation being a less common cause. While persistent CHL linked to malleus fixation can be managed with appropriate diagnosis and surgical intervention, recurrent CHL cases remain poorly documented. This report describes a rare case of recurrent CHL due to malleus neck fixation, likely secondary to surgical trauma. Case Presentation: A 49-year-old woman underwent bilateral stapedectomy. CHL worsened after two years. CT showed right incus erosion and a left bony bridge. Revision surgery corrected the right side. Left tympanotomy revealed malleus fixation from a prior atticotomy. Removing the bony bridge restored ossicular mobility and hearing, stable at 6 and 12 months. Discussion: Malleus fixation after stapedectomy is rare and often related to congenital anomalies, chronic otitis media, tympanosclerosis, or surgical trauma. Bone dust or fragments from surgery may promote new bone formation, causing delayed fixation. Ossicular fixation can develop postoperatively and may be missed during primary surgery. High-resolution CT aids in diagnosis, especially in revision cases, while intraoperative palpation is key to detecting subtle abnormalities. Treatment options include ossicular mobilization, prosthesis revision, or chain reconstruction, tailored to the fixation’s location and severity. Conclusions: Surgical trauma should be considered a potential cause of recurrent CHL post-stapedectomy. Thorough removal of bone debris through aspiration and irrigation during surgery is essential to minimize this risk and optimize long-term hearing outcomes. Full article

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. Full article