Search Results (510)

The skin’s physiological response to repetitive stress is not well understood in prosthesis users. Improving this understanding could facilitate the design of a diagnostic tool to determine if the skin is adapting to tolerate stress from a prosthetic socket. The objective of this research was to develop a physical system that mechanically stresses the skin in a controlled manner and then implements the imaging modalities of infrared (IR) imaging and optical coherence tomography (OCT). IR imaging characterizes the skin’s temperature response, while OCT characterizes vessel diameter changes over time in the skin. The system was implemented in a single individual with a transtibial amputation. The system reliably maintained the force profile throughout testing. IR and OCT imaging were initiated after load application, and all curves demonstrated an initial rise in temperature immediately after load removal followed by a decrease towards baseline. The system was able to effectively detect a peak outcome (temperature and vessel area) with both imaging modalities. The system’s ability to maintain the loading throughout and begin imaging to capture the peak provides promise for expanded use to better understand the skin’s physiological response to loading in prosthesis users. This improved understanding may better inform treatment strategies to optimize patient outcomes. Full article

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. Full article

Background/Objectives: The biologically oriented preparation technique (BOPT) is a vertical tooth preparation approach that eliminates a conventional finish line and positions the prosthetic margin within the gingival sulcus, aiming to promote peri-restorative soft tissue adaptation through controlled gingival remodeling. This article describes a clinical case report of a hybrid impression protocol combined with a digital workflow intended to address some of the main clinical limitations of BOPT, particularly the recording of deep subgingival margins and the transfer of the emergence profile from the provisional to the definitive restoration. Methods: The proposed technique combined a conventional silicone impression to obtain a complete reading of the gingival sulcus with intraoral digital scanning, complemented by extraoral scanning of the provisional restoration to reproduce its subgingival morphology within the definitive prosthetic workflow. Results: Within the limitations of a single clinical case with short-term follow-up, this hybrid approach showed a satisfactory esthetic outcome and favorable short-term peri-coronal soft tissue behavior. Conclusions: This hybrid workflow may represent a feasible clinical option for transferring the cervical contour and emergence profile to the definitive prosthesis in anterior BOPT restorations. Full article

Background and Objectives: Medial unicompartmental knee arthroplasty (UKA) has emerged as an effective surgical option for isolated medial compartment osteoarthritis (OA), offering advantages in bone preservation, knee kinematics, and postoperative recovery compared with total knee arthroplasty (TKA). Although numerous studies have evaluated the mid- to long-term outcomes of UKA, reports focusing on cohorts with follow-up periods exceeding 10 years remain relatively limited. The purpose of this study was to analyze the long-term clinical and radiological results of medial fixed-bearing UKA using the Miller-Galante prosthesis. Methods: Sixty-eight patients who underwent UKA at a single institution with at least 10 years of follow-up were retrospectively reviewed. Clinical outcomes were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and knee range of motion (ROM). Radiological parameters including the hip-knee-ankle axis angle (HKA) and osteoarthritis (OA) grade using the Kellgren-Lawrence (K-L) grading system were evaluated. Implant survivorship was evaluated using Kaplan–Meier survival analysis. Results: A total of 68 patients were included with a mean age of 56.8 ± 7.5 years at surgery and a mean follow-up of 170.9 ± 37.3 months. Significant improvement in the WOMAC score was observed from 48.9 ± 17.2 preoperatively to 23.8 ± 27.7 at final follow-up (p = 0.002). The cumulative survival rates were 97.1% at 10 years and 84.8% at 15 years with conversion to total knee arthroplasty as the endpoint. Significant improvement in the HKA was observed from 172.5° ± 4.4° to 174.3° ± 4.8° postoperatively (p = 0.002), though residual varus alignment persisted. Progressive OA was observed in the lateral tibiofemoral and patellofemoral compartments (both p < 0.001) but showed no correlation with the WOMAC score. The failure group showed trends toward higher body mass index (BMI) and smaller preoperative HKA angle compared to the non-failure group. Conclusions: The long-term outcomes of medial fixed-bearing UKA using the Miller–Galante prosthesis were generally favorable, with significant functional improvement and acceptable implant survivorship. Although overall varus alignment was corrected, some residual varus deformity remained, and OA progression was observed in the lateral tibiofemoral and patellofemoral compartments over time. However, given the retrospective design and limited sample size, these findings should be interpreted with caution. Full article

Background/Objectives: This technical report introduces an innovative hybrid digital workflow that integrates diagnostic plaster-cast scanning with intraoral scanning to produce an accurate 3D-printed model for fabricating distal-extension removable dental prostheses (RDPs). Methods: The technique aims to overcome the challenges of reproducing the mobile mucosa in free-end saddles, a critical factor for denture base accuracy and stability. The workflow began with conventional clinical procedures, including clinical examination, impression-making, and cast surveying. After performing the required mouth preparations according to the prosthetic design, the diagnostic cast was digitized and selectively modified to allow intraoral rescanning. The prepared teeth were then scanned intraorally and merged with the digitalized cast, producing a refined virtual model for CAD-based metal framework design. The framework was digitally designed, 3D-printed to verify adaptation, and cast in cobalt–chromium. Standard RDP fabrication steps were followed, including intraoral framework try-in, fabrication of acrylic bases, occlusal registration, tooth arrangement, and functional and esthetic try-in. The final prosthesis was installed and adjusted without the need for an additional impression. Results: This hybrid workflow enabled a highly accurate reproduction of the distal extension region, outperforming models derived solely from direct intraoral scanning. By digitally capturing the physiological morphology of the mobile mucosa, the method eliminates the need for the traditional altered-cast technique, reducing clinical time, technical sensitivity, and material costs. Conclusions: The proposed approach enhances denture base accuracy, improves adaptation, and promotes more uniform occlusal load distribution in free-end RDPs. This streamlined and reproducible digital protocol offers a clinically relevant advancement, with potential to improve prosthesis stability and long-term outcomes. Full article

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. Full article

Transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of severe aortic stenosis, evolving from a therapy reserved for inoperable patients to a first-line option across all surgical risk categories. As TAVR expands to younger patients with longer life expectancies, lifetime management strategies become paramount. This comprehensive review examines the important role of computed tomography (CT) planning in optimizing initial valve selection and predicting future reintervention feasibility. We discuss the decision framework between TAVR and surgical aortic valve replacement (SAVR) as initial therapy, strategies to optimize the index TAVR procedure, including minimizing patient-prosthesis mismatch, reducing paravalvular regurgitation, preventing conduction abnormalities and coronary obstruction, and facilitating future reinterventions. For patients requiring redo procedures, we analyse TAVR-in-TAVR considerations, including risk plane assessment, coronary access preservation, and leaflet modification techniques. Future directions include advances in valve design, artificial intelligence integration in procedural planning, and development of personalized risk assessment tools. Successful lifetime management requires multidisciplinary collaboration and individualized treatment planning to optimize outcomes throughout a patient’s lifetime journey with aortic valve disease. Full article

Background/Objectives: Thumb basal joint arthritis is a common degenerative condition often requiring surgery when conservative treatment fails. Dual mobility trapeziometacarpal prostheses are increasingly used, but the optimal anesthetic strategy remains debatable. This study aimed to explore whether WALANT provides intraoperative analgesia and short-term safety comparable to axillary block in dual mobility trapeziometacarpal arthroplasty. Methods: A prospective observational comparative study was carried out on 21 patients (11 WALANT, 10 axillary block) undergoing dual mobility trapeziometacarpal prosthesis for stage II–III in thumb basal joint arthritis according to Eaton–Littler classification at two hospital facilities of ASL Roma 5, from February–December 2025. Patients treated with the WALANT technique were assigned to Group A, whereas those undergoing an axillary block were assigned to Group B. Pain intensity was recorded on a 0–10 visual analogue scale at three stages: during anesthetic administration, during surgery, and 3 h after the procedure. Group A received a field infiltration with 1% mepivacaine combined with epinephrine 1:100,000 and sodium bicarbonate, while Group B underwent an ultrasound-guided brachial plexus block using 0.5–0.7% ropivacaine and a pneumatic tourniquet inflated to 250 mmHg. Results: Pain during anesthesia induction was similar between groups (Group A 3.18 ± 2.89 vs. Group B 2.20 ± 2.37, p = 0.393). Intraoperative pain did not differ significantly (Group A 2.27 ± 1.79 vs. Group B 2.00 ± 2.71, p = 0.898). At 3 h postoperative, Group B showed a trend toward lower pain levels (Group A 4.36 ± 2.54 vs. Group B 3.00 ± 3.08, p = 0.244). No anesthetic failures, no conversion to general anesthesia, and no neurological or ischemic complications occurred in either group. Conclusions: In this prospective observational comparative cohort, WALANT and axillary block provide comparable intraoperative analgesia for dual mobility trapeziometacarpal prosthesis, with comparable safety profiles. WALANT offers advantages in ease of administration, absence of tourniquet-related risks, and potential for intraoperative functional testing. Axillary block provides more prolonged postoperative analgesia in the first 3 h. The choice between techniques should be individualized based on patient-specific factors, anxiety profile, and local expertise. These results should be interpreted as preliminary and hypothesis-generating, given the exploratory design, the small sample size, and the limited statistical power of the study. Full article

Background: Rehabilitation of the severely atrophic maxilla remains a major challenge in implant dentistry, particularly when conventional endosseous implants and regenerative procedures are contraindicated due to extensive bone loss, sinus pathology, or patient-related factors. Advances in digital planning and additive manufacturing have enabled the reintroduction of juxta-osseous subperiosteal implants as a graftless, patient-specific treatment option. This case report aimed to describe the complete digital workflow, surgical placement, and immediate prosthetic rehabilitation of a customized juxta-osseous subperiosteal implant in a patient with severe posterior maxillary atrophy and a history of failed sinus augmentation procedures. Case Presentation: A 75-year-old male patient presenting with left severe posterior maxillary atrophy and previous unsuccessful sinus lift surgeries was rehabilitated using a digitally designed, additively manufactured titanium subperiosteal implant. Cone-beam computed tomography–based planning and CAD–CAM technology were used to design a patient-specific framework, which was rigidly fixed to stable maxillofacial support and immediately loaded with a screw-retained provisional prosthesis. Results: Clinical and radiographic follow-up demonstrated stable implant fixation, soft tissue healing, absence of biological or mechanical complications, and satisfactory functional and aesthetic outcomes. The patient reported high levels of comfort and satisfaction throughout the treatment period. Conclusions: Digitally manufactured juxta-osseous subperiosteal implants may represent a predictable and minimally invasive graftless alternative for selected patients with severe maxillary atrophy, particularly when conventional implant placement or extensive bone augmentation is not feasible. Accurate digital planning, rigid fixation, and appropriate patient selection appear to be key factors for clinical success. Full article

Full-arch zirconia prostheses for mandibular All-on-4 rehabilitations are provided as screw-retained monolithic zirconia (Zr-Mono) or as a zirconia suprastructure luted to a CAD/CAM titanium bar (Zr-TiBar). Because zirconia is a brittle and flaw-sensitive ceramic, design assessment should incorporate stress-field-weighted fracture risk. This in silico study compared zirconia tensile stress, deformation, and Weibull-based reliability between Zr-Mono and Zr-TiBar designs in a standardized edentulous mandibular All-on-4 model (posterior implants tilted 30°) using linear static finite element analysis. Accordingly, 300 N posterior unilateral loads were applied at the first molar (axial; 45° oblique). Outcomes were maximum principal tensile stress in zirconia (S1max), total prosthesis deformation, and Weibull-predicted fracture probability (Pf) derived from the tensile S1 field. Under axial loading, S1max was essentially identical between designs (~277 MPa). Under oblique loading, S1max was modestly lower for Zr-TiBar (~227 MPa) than for Zr-Mono (~234 MPa), and deformation was slightly lower for Zr-TiBar (<0.07 mm in all cases). Pf remained very low for both designs (10⁻⁶–10⁻⁷ range) and differed only slightly between them. Under the modeled single 300 N posterior load case, the titanium-bar support reduced deformation and modestly reduced oblique-load peak tensile stress but did not materially reduce the predicted zirconia Pf compared with monolithic zirconia. Full article

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). Full article

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. Full article

Background: Language serves as a significant barrier to accessing dental services. Dental treatment options are often complex and involve terminology that is unfamiliar to most patients. In some cases, dental students may use technical terms that patients do not understand, leading to confusion and misunderstandings. Therefore, this study aimed to assess the language barriers faced by dental students and patients in Riyadh, Saudi Arabia. Methods: A mixed-methods research design was employed to evaluate language barriers between dental students and patients, as it provides an in-depth understanding and generates information beyond mere numerical data. The study was conducted from 1 September 2024, to 30 August 2025, in Riyadh, Saudi Arabia. Data collection primarily involved conducting interviews with focus group members using a comprehensive topic guide consisting of predetermined questions. Results: Forty dental students and forty patients agreed to participate in this study. The students encountered significant difficulty explaining terms such as crown lengthening (72.5%) and periodontitis (67.5%), while patients reported limited understanding of interim removable dental prosthesis (65%) and fixed dental prosthesis (60%). Comparative analysis indicated that sixth-year students reported significantly more difficulty explaining “crown lengthening” and “prefabricated post and core” compared to fifth-year students. It was also observed that patients’ educational level had a significant impact on their understanding of terms such as “interim dental prosthesis” and “removable dental prosthesis.” Qualitative analysis revealed patients’ partial understanding or misinterpretation of dental terminologies. Conclusions: Our findings indicate that language discordance, even among speakers of the same native language, can hinder effective communication, particularly when technical vocabulary is involved. Students may struggle to explain procedures in a manner that patients can easily understand. This can lead to incomplete patient comprehension and potential non-compliance with treatment recommendations. Hence, we recommend incorporating Arabic dental terminologies alongside English into the curriculum, developing bilingual glossaries, and using visual aids when communicating with patients. 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

This study investigates the functional capabilities and accessibility limitations of current knee prostheses while developing and evaluating a three-stage prosthetic system (V1–V3). The primary objective is to design a cost-effective knee prosthesis featuring anatomically compatible motion, high kinematic accuracy, and a modular architecture. The methodology integrates a technical review of commercial prostheses, CAD modeling in SolidWorks, kinematic evaluation through Motion Simulation, and experimental testing of the V2 prototype. The results demonstrate the structural limitations of the initial V1 design, the complete assembly and improved functional performance of the V2 prototype, and the advanced mechanical behavior achieved in the final V3 concept. The V3 model provides an extended range of motion, reduced mass and lowered center of gravity, smoother dynamic response, and compatibility with a fully modular foot–ankle–knee configuration. Overall, the findings indicate that the V3 design represents a promising engineering solution that brings the system closer to clinical applicability and establishes a foundation for the development of a fully modular lower-limb prosthetic platform. Full article