Prosthesis

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

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. Full article

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. Full article

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. Full article

Background/Objectives: Metal–ceramic crowns may be constructed using different techniques and coping materials. A systematic review analysing the coping material, method of construction, and instruments used for measuring the metal–ceramic crown marginal gap has not been completed. The aim of this systematic review was to appraise the literature relating to the instruments used for the in vitro marginal gap measurement of single pre-cemented metal–ceramic crowns and assess whether the crown coping material and method of coping construction influence the marginal gap. Methods: A systematic search was performed in November 2024 across the EBSCO Host, Scopus, PubMed, and Web of Science databases, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and specific eligibility criteria. The Joanna Briggs Critical Appraisal Checklist was used to assess article quality. Results: Fourteen studies evaluated marginal gaps in 402 crowns using the following techniques: direct view microscopy (eight studies), replica techniques (three studies), scanning electron microscopy (two studies), and profilometry (one study). The mean marginal gap for all the metal–ceramic crowns across all the studies was 65.97 ± 32.58 µm. The pre-cementation mean marginal gaps showed no significant difference between Computer-Aided Design–Computer-Aided Manufacturing (CAD-CAM) milled copings (87.95 ± 26.35 µm) and conventionally cast copings (90.45 ± 24.37 µm) (t = −0.197, p = 0.847). The mean marginal gaps varied significantly (F = 11.34, p < 0.001) by coping material: cobalt–chromium (Co-Cr) led to 84.28 µm, nickel–chromium (Ni-Cr) led to 70.98 µm, titanium led to 50.18 µm, and noble metal alloys led to 27.90 µm. Six studies addressed confounding factors and followed a standardised approach for measuring marginal gaps. Conclusions: Direct view microscopy was the most commonly used instrument for measuring the marginal gaps of single pre-cemented metal–ceramic crowns, yielding the smallest reported mean marginal gap of 75.00 ± 26.87 µm. Metal–ceramic crowns constructed with noble metal alloys exhibited the lowest mean marginal gaps. Metal–ceramic crowns constructed using conventional casting techniques presented similar marginal gaps to CAD-CAM crowns. Full article

Objectives: The presence of gingival buccal recession is a frequent problem especially in the canine area. The cortical buccal bone may be absent in presence of health normal lingual/palatal bone and of other periodontal pockets. The present case report describes a minimally invasive approach in a 76-year-old patient with previously endodontically treated lower canine affected by root fracture and by a serious chronic buccal recession. Methods: The tooth was characterized by a deep vestibular bone defect, lack of buccal bone and acute periapical lesion. After extraction, Maryland bridge was positioned on the edentulous area. A two-piece convergent neck transmucosal implant was inserted with a flapless approach after 6 months. Maryland bridge was left in place for additional 3 months. After this time, digital impressions were taken, and a customized abutment was positioned. A provisional crown was designed according to Biologically Oriented Preparation Technique (BOPT) concept and maintained for 6 months. A zirconia definitive crown was digitally designed and cemented with a polycarboxylate-based cement. The Pink Esthetic Score (PES) was used as an index to assess peri-implant soft tissue stability over time (preoperatively, at 9 months, at 12 months and 72 months). Results: The patient was followed for 6 years under a conventional hygienic recall program. No complications occurred, and the PES improved from 4 preoperatively to 8 at 9 months, 10 at 12 months and 13 at 72 months. Conclusions: The use of Maryland bridge prevented occlusal trauma on healing tissues and appeared to support bone and soft tissue healing for transmucosal implant placement. A stable aesthetic rehabilitation was achieved up to 6 years. Full article

Background: A promising improvement in orthodontic diagnostics is the use of convolutional neural networks (CNNs) to predict skeletal maturity using dental radiographic data, namely the calcification phases of the lower canine. Objectives: The purpose of this study is to improve the prediction of skeletal growth maturation through the use of sophisticated deep learning techniques, particularly CNNs, in the analysis of orthopantomography developmental markers. Methods: The CNN was trained and validated using the suggested model, which enables precise assessment of skeletal maturity across data collected from patients undergoing orthodontic and dental evaluations. By using a multiclass classification framework to classify the various stages of skeletal maturation. Results: CNN model predicting the development of the lower canine from the second molar provided a test accuracy of 97.50%, the model made it possible to automatically interpret radiographic features that were previously evaluated manually. Conclusions: CNN models can be trained to correctly identify the lower canine calcification stage, this helped clinicians with treatment planning and timing, especially with regard to growth modification, implant, prosthodontics approach and its clinical applicability. It guarantees ethical imaging procedures and optimizes clinical workflows by doing away with the necessity for further imaging. Full article

Purpose: The study aimed to assess and compare the fracture toughness of resin-bonded fixed dental prosthesis (RBFDP) of different ceramic materials and connector parameters. Methods: Twenty extracted human incisal teeth were utilized as abutments for the RBFDP. Zirconia (Zir) and lithium disilicate (LD) were manufactured in the form of anterior cantilever RBFDPs (n = 10 per group). Each material was tested using two connector designs, with the following dimensions for height (h), base (b), and width (w): 5 (h) × 4 (b) × 1 (w) mm (n = 5), and 4 (h) × 2 (b) × 1 (w) mm (n = 5). Prostheses were computer-aided design and computer-aided manufacturing (CAD/CAM) fabricated from Zir (IPS e.max ZIRCAD prime) and LD (IPS e.max CAD). Surface pretreatment of the prosthesis was completed prior to cementation with a dual-cured resin cement (Rely-X Ultimate). The combined teeth and prostheses were subjected to thermocycling before load-to-fracture testing at 45-degrees in the center of the pontic using a universal testing machine (Shimadzu Universal Testing Machine). The types of fracture failures were observed and classified as either favorable (non-catastrophic/repairable) or unfavorable (catastrophic/non-repairable) when viewed under an electron microscope. Results: The highest fracture toughness was observed in 5 (h) × 4 (b) × 1 (w) mm for Zir, reaching 269 ± 27 N, and LD, reaching 180 ± 83 N. The lowest values were found in 4 (h) × 2 (b) × 1 (w) mm for Zir at 237 ± 52 N and LD at 116 ± 25 N. Two-way ANOVA showed the fracture strength for dimension 5 (h) × 4 (b) × 1 (w) mm was significantly higher compared to dimension 4 (h) × 2 (b) × 1 (w) mm after adjusting for the type of material (p = 0.02). One Zir sample, measuring 5 (h) × 4 (b) × 1 (w) mm, exhibited tooth fracture under applied load. Meanwhile, two LD samples of the same dimensions became decemented under load. Conclusions: RBFDPs made from Zir exhibited a pattern of higher load-to-fracture values compared to LD for all dimensions; however, this was not statistically significant. The connector parameter has a more significant influence compared to the material used to fabricate an RBFDP in the anterior region. Full article

Background/Objectives: Auricular epitheses play a vital role in restoring facial symmetry and patient confidence following congenital or acquired defects. Traditional wax-based fabrication is labor-intensive and lacks reproducibility. This study proposes and evaluates a simplified, digitally driven workflow for auricular prosthesis manufacturing, integrating virtual patient creation, mirrored ear design, and three-part mold fabrication using two design platforms—CATIA V5R21 (industrial CAD) and Blender (open-source graphics software). Key outcomes include mold reusability, patient-centered evaluation, and workflow feasibility. Methods: A 28-year-old female patient with right-sided microtia was selected. A light-based 3D facial scan was performed, and the intact contralateral ear was mirrored and adapted virtually to the defect site. Molds were designed in both CATIA and Blender using a standardized three-parallelepiped approach and printed using FDM technology (Elegoo Neptune 4 Plus). Five silicone epitheses were carefully fabricated with each mold. Surface trueness was evaluated with Geomagic Control X, while subjective assessments were conducted by an independent prosthetic team and the patient using Visual Analogue Scales (VAS). Results: Both design workflows resulted in clinically usable prostheses. No statistically significant difference in RMS deviation was observed (p = 0.53), although CATIA-derived epitheses achieved higher subjective scores (mean 9.22/10) compared to Blender (mean 7.67/10). The preferred prosthesis (CATIA #4) was selected for final pigmentation and delivery to the patient. All molds were reused five times without any structural damage or significant signs of wear. Conclusions: This study demonstrates that both CATIA and Blender can support an effective, patient-centered digital workflow for auricular prosthesis fabrication. The methodology enables reproducibility, mold reusability, and improved clinical accessibility of custom prosthetics. Full article

Background: Dental implants have become integral in restoring partially or completely edentulous patients due to their reported long-term success. While titanium remains the primary material for implants and abutments due to its mechanical properties and biocompatibility, zirconia has emerged as a promising alternative, especially for aesthetic regions. This systematic review aimed to assess whether zirconia abutments present a rational alternative to titanium in modern implantology, focusing on their mechanical and clinical performances. Method: The workflow used for this review included the PRISMA checklist. The eligibility criteria included various study types, with a preference given to clinical trials. The search strategy employed the PICO model, including a large number of relevant studies, and online research was carried on the online databases PubMed and Scopus, with “implant” AND “abutment” AND “zirconia” and “zirconia abutment” AND “mechanical properties” used as search strings. Results: Six clinical studies were included with an adequate follow-up and patient cohort; they suggest that while zirconia abutments offer improved aesthetics and biological integration, concerns persist regarding their mechanical properties, particularly regarding their fatigue resistance and connection stability. In vitro studies have revealed differences between titanium and zirconia abutments, with the latter showing greater susceptibility to fatigue-induced deformation and fretting wear. The clinical outcomes, however, demonstrate favourable long-term performance, with zirconia abutments promoting healthy soft tissue conditions. CAD/CAM technologies enable the precise customization of zirconia abutments, enhancing their compatibility and aesthetic outcomes. Conclusions: Although this review faces limitations due to the scarcity of comparative studies and varied methodologies, it underscores the potential of zirconia abutments in implantology. In conclusion, while zirconia abutments offer promising advantages, the careful consideration of patient-specific factors and the long-term outcomes is warranted for their optimal utilisation in implant-supported prostheses. Full article

Background/Objectives: Maxillary defects, whether congenital or acquired, can compromise chewing, speech, and aesthetics. This systematic review aimed to evaluate the application and characteristics of definitive palatal obturators in the rehabilitation of such defects, analyzing techniques of fabrication, materials, outcomes of the fabrication, and limitations reported in the literature. Methods: The review was conducted in accordance with PRISMA 2020 guidelines and was registered in PROSPERO (ID: 1011648). A comprehensive search was performed in PubMed, Scopus, Lilacs, and Google Scholar for studies published from 1 January 2014 to 1 January 2025. Inclusion criteria comprised adult patients treated with definitive palatal obturators and with reported follow-up. Exclusion criteria included studies on children, animals, or lacking patient data. Two reviewers independently screened studies and assessed eligibility. Bias was evaluated qualitatively across five domains. No meta-analysis was conducted; data were synthesized descriptively using charts and tables. The study was funded by the Italian Ministry of Health—Current Research IRCCS. Results: A total of 59 studies involving 83 patients (46 males, 37 females; mean age 54.6 ± 13.8 years) were included. Mucormycosis and squamous cell carcinoma were the primary causes of defects. Conventional impressions using alginate and silicone were most common, while digital techniques were reported in only 6.6% of cases. All definitive obturators were fabricated using acrylic resin, with some featuring hollow bulbs, velopharyngeal extensions, or magnetic retention. Multiple sources of bias were observed. Conclusions: Definitive palatal obturators provide effective functional and aesthetic rehabilitation for maxillary defects. However, evidence is limited by methodological weaknesses, lack of standardization, and underutilization of digital technologies. Future studies should focus on improving reporting quality, adopting innovative fabrication protocols, and generating higher-level clinical evidence to support best practices. Full article

Background/Objectives: Upper limb amputation presents considerable physical and psychological challenges, especially in young, active individuals. This case study outlines the rehabilitation journey of a 33-year-old patient, an Italian national Paralympic snowboard cross athlete, who underwent elective transradial amputation followed by advanced surgical and prosthetic interventions. The objective was to assess the combined impact of upper limb Targeted Sensory Reinnervation (ulTSR) and the Adam’s Hand prosthetic system on functional recovery and user satisfaction. Methods: After a partial brachial plexus injury caused complete paralysis of his right hand, the patient opted for transradial amputation. He subsequently underwent ulTSR, performed by plastic surgeon, Alexander Gardetto, MD, which involved rerouting sensory nerves to defined regions of the residual limb in order to reestablish a phantom limb map. This reinnervation was designed to facilitate improved prosthetic integration. The Adam’s Hand, a myoelectric prosthesis with AI-based pattern recognition, was selected for its compatibility with TSR and intuitive control. Outcomes were evaluated using the OPUS questionnaire, the DASH, and patient feedback. Results: ulTSR successfully restored meaningful sensory input, allowing intuitive and precise control of the prosthesis, with minimal cognitive and muscular effort. The patient regained the ability to perform numerous activities of daily living such as dressing, eating, lifting, and fine motor tasks—which had been impossible for over 15 years. OPUS results demonstrated significant improvements in both function and satisfaction. Conclusions: This case highlights the synergistic benefits of combining ulTSR with user-centered prosthetic technology. Surgical neurorehabilitation, paired with advanced prosthetic design, led to marked improvements in autonomy, performance, and quality of life in a high-performance amputee athlete. Full article

Aim: This study evaluated the effect of manual and electronic toothbrushes on the color stability (∆E*) and surface roughness (Ra) of four CAD/CAM ceramics after their immersion in coffee for 2 and 4 weeks. Methodology: A total of 160 specimens (Vitablocs Mark II, Ceramill Zolid zirconia, Vita Triluxe Forte, and IPS e.max CAD) were divided into four brushing subgroups (manual, sonic, oscillating–rotating, and ionic). The samples underwent daily coffee staining, thermocycling (5–55 °C), and twice-daily brushing. Color parameters (L, a, and b) were assessed and measured utilizing a spectrophotometer (Vita Easyshade) at baseline, 2 weeks, and 4 weeks. ∆E* was calculated using the CIEDE2000 formula, and surface roughness (Ra, µm) was assessed via contact profilometry at the study’s conclusion. Data were analyzed using Kruskal–Wallis and Mann–Whitney tests (α = 0.05). Results: Among the tested samples, IPS e.max ceramic with manual toothbrushing exhibited the highest ΔE* values after 2 and 4 weeks (∆E* = 4.424 and ∆E* = 4.802) of immersion. Moreover, Ceramill Zolid zirconia demonstrated the highest ΔE* values with ionic brushing (∆E* = 4.883 at 2 weeks; ΔE* = 4.760 at 4 weeks). Significant differences were observed among ceramics and cleaning methods, with manual/ionic brushing causing the greatest changes (p < 0.05). IPS e.max had the highest Ra with manual brushing (0.745–0.789 µm), whereas Ceramill Zolid zirconia with ionic brushing showed the highest Ra values among the electric methods (0.745–0.757 µm). Conclusions: Manual brushing induced clinically unacceptable color changes in IPS e.max CAD, whereas ionic brushing adversely affected Ceramill Zolid zirconia. All brushing methods increased surface roughness beyond acceptable limits. Full article

Objective: The aim of this study was to evaluate and compare the clinical behavior of indirect onlays/overlays made of lithium disilicate and composite resin and to investigate risk factors associated with restoration failures. Methods: 112 indirect partial coverage posterior restorations (onlays and overlays) placed in 51 adult patients between January 2014 and December 2020 were examined. The restorations were evaluated using selected FDI criteria (color match, surface gloss, anatomic form, fracture of restorative material, tooth cracks and fractures, marginal discoloration, marginal integrity and recurrence of initial pathology). The survival of the restorations was analyzed using Kaplan–Meier method. Risk factors (type of restoration, type of tooth, tooth vitality, smoking) were investigated using Cox regression analysis. Risk estimation was conducted for each evaluated criterion (p < 0.05). Results: For composite restorations, the estimated survival rate was 94.2% after 5 years, dropping to 74.3% in 7.9 years and continued falling to less than 60% after 8.2 years. On the contrary, for lithium disilicate restorations the estimated survival rate was 90.9% after 5 years, dropped to 85.2% after 5.5 years remaining stable thereafter. Lithium disilicate onlays demonstrated significantly better performance than lithium disilicate overlays. Cox regression analysis did not reveal any significant association between the survival of the indirect partial restorations and restoration material, tooth type, restoration type and history of endodontic treatment. However, smoking was found to be a statistically significant risk factor (p < 0.05). Conclusions: Lithium disilicate and composite indirect restorations exhibited comparable survival rates at the early observation period. However, lithium disilicate partial coverage restorations demonstrated more favorable clinical behavior compared to composite in the long term, with statistical significance observed in ceramic vs. composite onlays. Full article

Background/Objectives: Computer-aided manufacturing techniques are divided into subtractive (milling) and additive (3D printing) techniques. The accuracy of both techniques is measured only indirectly by testing the fabricated restorations. However, the role of the fabrication technique is masked by the differences in the materials used. Hence, this study used the same printing resin to print crowns and blocks for milling. Methods: Ten maxillary first premolars were prepared for full crowns and scanned with Primescan Connect IOS, and then crown restorations were designed using Exocad. A CAD/CAM block equal to size C14 was designed in CAD software (Microsoft 3D Builder) (Version 18.0.1931.0). The designed crowns and blocks were printed using three hybrid ceramic materials, namely, Ceramic Crown (SprintRay), Varseosmile Crown plus (Bego), and P-crown (Senertek), using a SprintRay Pro95S 3D-printer. The printed blocks were then used to fabricate the designed crowns using an In-Lab MCXL milling machine. The trueness and marginal and internal gaps of the crowns were then measured using Geomagic Control X metrology software (Version 2022.1). Statistical analysis was performed using the Kruskal–Wallis test, Dunn’s test, one-way ANOVA test, and Tukey’s HSD test. Results: Generally, the milled crowns showed significantly higher trueness but lower fitness than their 3D-printed counterparts (p < 0.05). A significant reverse correlation was found between the trueness and fitness of the fabricated restorations. Conclusions: The fabrication technique significantly influenced the accuracy of the hybrid ceramic crowns. Milling offered superior trueness, whereas 3D printing resulted in better internal and marginal adaptation. Full article

Background/Objectives: This study aimed to identify the functional adaptations that enable competitive performance in a Paralympic cyclist with optimized bilateral transtibial prostheses compared to a conventional cyclist. Additionally, it describes the development of the prosthesis, designed through a user-centered engineering process incorporating Quality Function Deployment (QFD), Computer-Aided Design (CAD), Finite Element Analysis (FEA), Computational Fluid Dynamics (CFD), and topological optimization, with the final design (Design 1.4) achieving optimal structural integrity, aerodynamic efficiency, and anatomical fit. Methods: Both athletes performed a progressive cycling test with 50-watt increments every three minutes until exhaustion. Cardiorespiratory metrics, lactate thresholds, and joint kinematics were assessed. Results: Although the conventional cyclist demonstrated higher Maximal Oxygen Uptake (VO₂max) and anaerobic threshold, the Paralympic cyclist exceeded 120% of his predicted VO₂max, had a higher Respiratory Exchange Ratio (RER) [1.32 vs. 1.11], and displayed greater joint ranges of motion with lower trunk angular variability. Lactate thresholds were similar between athletes. Conclusions: These findings illustrate, in this specific case, that despite lower aerobic capacity, the Paralympic cyclist achieved comparable performance through efficient biomechanical and physiological adaptations. Integrating advanced prosthetic design with individualized evaluation appears essential to optimizing performance in elite adaptive cycling. Full article

Background/Objectives: Hip-level amputees face ambulatory challenges due to the lack of a lower limb and prosthetic hip power. Some hip-level amputees restore mobility by using a prosthesis with hip, knee, and ankle joints. Powered prosthetic joints contain an actuator that provides external flexion-extension moments to assist with movement. Powered knee and powered ankle-foot units are on the market, but no viable powered hip unit is commercially available. This research details the development of a novel powered four-bar prosthetic hip joint that can be integrated into a full-leg prosthesis. Methods: The hip joint design consisted of a four-bar linkage with a harmonic drive DC motor placed in the inferior link and an additional linkage to transfer torque from the motor to the hip center of rotation. Link lengths were determined through engineering optimization. Device strength was demonstrated with force and finite element analysis and with ISO 15032:2000 A100 static compression tests. Walking tests with a wearable hip-knee-ankle-foot prosthesis simulator, containing the novel powered hip, were conducted with three able-bodied participants. Each participant walked back and forth on a level 10 m walkway. Custom hardware and software captured joint angles. Spatiotemporal parameters were determined from video clips processed in the Kinovea software (ver. 0.9.5). Results: The powered hip passed all force and finite element checks and ISO 15032:2000 A100 static compression tests. The participants, weighing 96 ± 2 kg, achieved steady gait at 0.45 ± 0.11 m/s with the powered hip. Participant kinematic gait profiles resembled those seen in transfemoral amputee gait. Some gait asymmetries occurred between the sound and prosthetic legs. No signs of mechanical failure were seen. Most design requirements were met. Areas for powered hip improvement include hip flexion range, mechanical advantage at high hip flexion, and device mass. Conclusions: The novel powered four-bar hip provides safe level-ground walking with a full-leg prosthesis simulator and is viable for future testing with hip-level amputees. Full article

Background/Objectives: Tapered, fluted, modular titanium stems (TFTSs) are widely used in complex femoral reconstructions during total hip arthroplasty (THA), but evidence regarding the clinical performance of specific modular implant designs remains limited. This study aimed to compare the early clinical and radiographic outcomes of complex primary and revision THA using the M-Vizion^® modular stem system. Methods: We retrospectively analyzed 109 patients (46 complex primary and 63 revision THA cases) treated with the M-Vizion^® cementless modular TFTSs between 2020 and 2023. Clinical outcomes were assessed using the Hip Disability and Osteoarthritis Outcome Score (HOOS) and the Forgotten Joint Score (FJS) at 1- and 2-years post-surgery. Radiographic evaluation included stem subsidence, radiolucent lines, heterotopic ossification, and complications. Clinically relevant subsidence was defined as >5 mm. Statistical analysis was performed using ANOVA. Results: The mean follow-up was 33.3 months for complex primary and 31.8 months for revision THA. Both groups demonstrated significant improvement in FJS over time (p < 0.05). In the revision group, HOOS improved significantly from baseline to follow-up (p < 0.001). Mean stem subsidence was 2.1 mm in the complex primary group and 1.8 mm in the revision group; nine patients (8.3%) had subsidence greater than 5 mm. No cases of aseptic loosening or stem fracture were observed. The overall complication rate was low, with dislocations (3.2%) and infections (2.8%) requiring revision. Conclusions: The M-Vizion^® TFTS system demonstrated favorable short-term outcomes in both complex primary and revision THA. These findings suggest potential utility in complex femoral reconstruction, although confirmation through longer-term studies is warranted. Full article