Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine最新文献

{"title":"A feature-driven registration method for low-overlap partial matching of CBCT and IOS dental models.","authors":"Zhixian Qiu, Jingang Jiang, Jiawei Zhang, Jie Pan, Kun Qian, Jinxu Zhao","doi":"10.1177/09544119261475397","DOIUrl":"10.1177/09544119261475397","url":null,"abstract":"<p><p>Accurate registration of cone-beam computed tomography (CBCT) and intraoral scanner (IOS) dental models is essential for diagnosis and preoperative planning. However, reliable alignment remains challenging because IOS data primarily represent the crown surface whereas CBCT provides complete tooth morphology with lower surface fidelity, resulting in substantial cross-modal discrepancy and limited geometric overlap. This study proposes a training-free spectral-topological feature-driven registration framework (STFR) for robust CBCT-IOS alignment under low-overlap conditions. STFR resamples the CBCT point cloud using Divergence Index and Improved Euclidean Clustering Rules (DI-IECR), then establishes reliable coarse correspondences via curvature-topology features and geometric-topological confidence domains. During fine registration, Laplacian spectral features are integrated with geometric-topological descriptors in an adapted iterative closest point framework to improve global structural consistency and reduce convergence to anatomically incorrect local optima. A neighborhood-curvature-based strategy then improves crown-root continuity. The framework was evaluated on 14 paired CBCT-IOS tooth models covering different morphologies and overlap conditions, using surface-distance metrics, spatial overlap ratio, and landmark-based target registration error (TRE) at the case level. STFR achieved a mean RMSE of 0.475 mm and a mean landmark TRE of 0.621 mm, outperforming five representative baselines (ICP, NDT, CPD, FPFH-RANSAC, and a fine-tuned DCP), with RMSE reductions of 29%-59% and significantly lower error in every paired comparison (all <i>p</i> < 0.01). STFR thus provides an interpretable, robust approach for low-overlap CBCT-IOS registration, although prospective clinical validation remains necessary before routine use.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"946-961"},"PeriodicalIF":1.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148851267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanical evaluation of surface texturing and hybrid coatings in dental implants: A finite element analysis of stress distribution under bone loss conditions.","authors":"Vamsi Krishna Dommeti, Mohadese Rajaeirad, Pechimuthu Susai Manickam, Balamurugan Subramanian, Francesco Valente, Raphael Richert, Sandipan Roy","doi":"10.1177/09544119261477915","DOIUrl":"10.1177/09544119261477915","url":null,"abstract":"<p><p>This study evaluates the biomechanical influence of surface texturing and hybrid coatings on stress distribution and marginal bone loss (MBL) in dental implants under varying bone loss conditions and axial loading. A parametric three-dimensional finite element model (FEM) of the human mandible was developed, consisting of cortical and cancellous bone layers. Five implant surface textures-Dome, Straight, U-Shape, X-Shape, and V-Shape-were considered, along with four hybrid coatings: hydroxyapatite (HA), HA with 3% tantalum pentoxide (HA3TO), HA with 3% strontium (HA3Sr), and HA with a combination of 1.5% tantalum pentoxide and 1.5% strontium (HA1.5TO1.5Sr). The implants were subjected to static axial loads (100, 150, 200, and 250 N). The V-Shape implant with HA1.5TO1.5SR exhibited the highest implant stress (97.13 MPa at 250 N), exceeding the 35 MPa cortical bone yield threshold, indicating an increased risk of mechanical overload and resorption. Dome-Shape and U-Shape textures demonstrated improved stress distribution, reducing peak stresses and enhancing stability. Hybrid coatings lowered implant stress by 19.65%, mitigating bone remodeling risks. Bone loss amplified stress concentrations, with higher micromotion risks observed in V-Shape and Straight-Shape textures. Surface texturing and hybrid coatings significantly influence peri-implant stress and stability. Based on our findings, Dome-Shape and U-Shape textures, combined with hybrid coatings, offer biomechanical advantages for implant longevity. These findings support the clinical preference for coated, curved-surface implants, particularly in patients with compromised bone quality.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"935-945"},"PeriodicalIF":1.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148761770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanical effects of far-cortex over-penetration in locking plate fixation: A finite element study.","authors":"Natig Valiyev, Cihan Zaman","doi":"10.1177/09544119261476357","DOIUrl":"10.1177/09544119261476357","url":null,"abstract":"<p><p>This study quantified the biomechanical consequences of incremental far-cortex over-penetration at terminal locking screw positions in a locking compression plate construct using a validated three-dimensional finite element model of a femoral diaphyseal fracture (AO/OTA 32-A3). Four terminal screw engagement configurations were evaluated: unicortical fixation, fully contained bicortical fixation, 1-thread over-penetration (0.6 mm), and 3-thread over-penetration (1.8 mm). Axial compression (1000 N), torsional loading (±10 Nm), and cyclic dynamic loading (100-1000 N, 1 × 10⁶ cycles) simulating the 8-week early postoperative period were applied. Model validation against published experimental data demonstrated agreement within 4% for all key biomechanical parameters. Fully contained bicortical fixation was the only configuration to remain below the predicted fatigue threshold, demonstrating the lowest peak von Mises stress (74.8 MPa) and a Miner's cumulative damage index of <i>D</i> = 0.291. Unicortical fixation (<i>D</i> = 1.103), 1-thread over-penetration (<i>D</i> = 1.362), and 3-thread over-penetration (<i>D</i> = 2.968) all exceeded the failure threshold (<i>D</i> ≥ 1.0). Under the loading conditions and material assumptions of the present finite element model, unicortical terminal fixation alone did not sustain simulated cyclic physiological loading during the pre-callus phase without exceeding the predicted fatigue damage threshold. These findings provide preliminary, model-dependent computational evidence suggesting that fully contained bicortical fixation may offer greater fatigue resistance, and that the biomechanical basis of current terminal screw placement guidelines warrants further experimental investigation.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"902-910"},"PeriodicalIF":1.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148685583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational biomechanical analysis of medial displacement calcaneal osteotomy placement and orientation.","authors":"Cecily James Marden, Bo Aletha Pilarczyk, Aaron Bhattachan, Willem Koenders, Bedri Karaismailoglu, Soheil Ashkani-Esfahani, Omer Subasi","doi":"10.1177/09544119261480789","DOIUrl":"10.1177/09544119261480789","url":null,"abstract":"<p><p>Medial displacement calcaneal osteotomy (MDCO) is commonly used to correct valgus hindfoot alignment in progressive collapsing foot deformity, but the biomechanical effects of osteotomy placement and Chevron apex geometry within the surgical safe zone remain unclear. This study evaluated how oblique cut position and Chevron apex orientation affect construct stiffness and stress distribution using patient-specific finite element models. Weight-bearing CT-derived models of the distal tibia, talus, and calcaneus were generated for seven patients. Nine MDCO configurations were simulated per patient: three oblique cut positions (anterior, middle, posterior) and six Chevron configurations varying by apex angle (130°, 150°, 170°) and apex position (anterior, posterior), yielding 63 simulations. Models incorporated cortical-cancellous bone separation, frictional osteotomy contact, patient-specific body-weight loading, and simplified Achilles tendon and plantar fascia forces. Axial stiffness, screw top 5% average von Mises stress, and osteotomy top 5% average von Mises stress were compared using within-subject analyses. Oblique cut position did not significantly affect stiffness (<i>p</i> = 0.149) or screw stress (<i>p</i> = 0.349), but significantly affected osteotomy stress (<i>p</i> < 0.001). Anterior oblique placement produced higher osteotomy stress (5.23 ± 1.25 MPa) than middle (4.18 ± 0.84 MPa, <i>p</i> = 0.005) and posterior placement (3.70 ± 0.98 MPa, <i>p</i> = 0.002). Chevron apex angle did not significantly affect any outcome. However, posterior Chevron apex placement produced higher osteotomy stress than anterior placement (4.79 ± 0.69 vs 4.07 ± 0.53 MPa, <i>p</i> = 0.011). These findings suggest that local osteotomy-surface stress is more sensitive to MDCO geometry than global stiffness or screw stress.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"911-920"},"PeriodicalIF":1.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148831852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accuracy and safety of individualized 3D-printed guides for L4 pedicle screw placement: An in vitro comparison with the free-hand technique.","authors":"Zhihao Qin, Jiaming Tan, Fan Yang, Zhirui Lu, Zhongshu Shan, Dedong Gao","doi":"10.1177/09544119261477149","DOIUrl":"10.1177/09544119261477149","url":null,"abstract":"<p><p>Pedicle screw fixation is widely utilized for lumbar stabilization, but deviation from the planned pedicle corridor may result in cortical breach and neurovascular injury. Individualized 3D-printed guides may help transfer preoperative planning to screw insertion. However, their guiding performance and measurement reliability still require quantitative validation in controlled L4 models. This in vitro comparative study evaluated the accuracy, safety, and measurement reliability of guide-assisted L4 pedicle screw placement. Five L4 vertebrae were selected from a public spine CT dataset to design and print individualized guides and corresponding bone models. Bilateral screw placement was performed in both the guide-assisted and free-hand groups. Postoperative CT scans were registered to preoperative planning models to assess entry point deviation, 3D angular error, axial and sagittal plane angular errors, and Gertzbein-Robbins (GR) grading. Registration quality and the reliability of repeated measurements were also evaluated. The guide-assisted group showed lower positional and angular errors than the free-hand group across all quantitative metrics, and this pattern was consistent across the five paired specimens. A higher strict Grade A rate was observed in the guide-assisted group, although both groups achieved a 100% clinically acceptable rate (Grade A + B). These findings suggest that individualized 3D-printed guides may improve the reproduction of planned L4 pedicle screw trajectories in printed bone models. Because only five independent L4 specimens were included and PLA models cannot reproduce bone density or tactile feedback needed for free-hand placement, the between-group comparison should be interpreted as exploratory in vitro geometric evidence. The workflow provides a quantitative framework for the in vitro evaluation of guide-assisted screw placement.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"921-934"},"PeriodicalIF":1.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148758741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can LLMs reliably perform epidemiological extraction in elite football?","authors":"Julio López-Álvarez, Adrián Feria Madueño","doi":"10.1177/09544119261484234","DOIUrl":"https://doi.org/10.1177/09544119261484234","url":null,"abstract":"<p><p>Anterior cruciate ligament (ACL) injuries remain a critical burden in professional football, resulting in prolonged absence and high economic costs. While physical demands have increased, traditional epidemiological surveillance relies on manual data extraction, which is resource-intensive and subjective. Large Language Models (LLMs) offer a potential solution for automated screening, but their reliability in sports medicine remains largely unexplored. This study aimed to: (1) update the epidemiology of ACL injuries in the Spanish First Division (LaLiga) over six consecutive seasons (2019/2020-2024/2025) and (2) validate the accuracy of an AI-assisted screening approach using ChatGPT compared to manual data extraction. A retrospective observational study was conducted using publicly available sources. Manual screening by external investigators (gold standard) was compared against an AI-assisted workflow based on a structured prompt-engineering framework. Analyses focused on injury frequency, mechanism, return-to-play (RTP) time, recurrence rates, and AI case-detection sensitivity. A total of 56 ACL injuries were identified in 52 players. Findings revealed a predominance in defenders (41.1%), a high prevalence of non-contact mechanisms (67.9%), and a median RTP of 280 days. Notably, the match-to-training injury ratio was 1.8-1, a significantly narrower gap than historical records. The recurrence rate was 17.9%, with 70% of cases occurring in the contralateral knee. Methodologically, the AI model exhibited a learning curve: 44.4% sensitivity in the initial refinement season (2019/2020), which progressed to a sustained 100% sensitivity across the following five seasons (2020-2025). ACL injury incidence in LaLiga remains stable, but the narrowing match-to-training ratio suggests that modern training intensities are reaching competitive levels of biomechanical stress. LLMs, once optimized through prompt engineering, provide a highly reliable and scalable tool for near real-time epidemiological surveillance, representing a methodological milestone in sports medicine research.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261484234"},"PeriodicalIF":1.8,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148866096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the agreement and reliability of Magene^® for heart rate monitoring.","authors":"Mila Alves Matos Rodrigues, Thiago Danillo Silva, Jessika Teodoro Santos, Vinnycius Nunes de Oliveira, Nicolas Evangelista Marques, João Victor Rosa de Freitas, Marilia Santos Andrade, Rodrigo Luiz Vancini, Beat Knechtle, Katja Weiss, Ricardo Borges Viana, Claudio Andre Barbosa de Lira","doi":"10.1177/09544119261477973","DOIUrl":"https://doi.org/10.1177/09544119261477973","url":null,"abstract":"<p><p>To evaluate the accuracy and reliability of the Magene^® heart rate (HR) monitor compared to the Polar^® H7 (validated device) during rest, maximal graded exercise test, and active recovery. A within-group study was conducted with 68 healthy adults (21 women). Participants completed two laboratory sessions using both monitors in random order. HR values were collected at rest, during the Ellestad maximal treadmill stress testing protocol, and in active recovery. Relative reliability was assessed using the two-way random effects intraclass correlation coefficient for agreement (ICC(2,1)). Absolute reliability was assessed using typical error (TE, in bpm and %), coefficient of variation (CV, %), and minimal detectable change (MDC, in bpm and %). Agreement was examined using Wilcoxon signed-rank tests, Bland-Altman plots, and Pearson's <i>r</i> or Spearman's rho, as appropriate. No significant HR differences were found between devices (<i>p</i> > 0.05). Mean biases, calculated as Polar - Magene, were 1.421 bpm at rest, 0.659 bpm during exercise, 0.103 bpm at maximal effort, and 0.569 bpm during active recovery. ICC(2,1) values ranged from 0.656 (rest) to 0.881 (maximal effort). TE ranged from 3.784 bpm (2.0%) to 6.470 bpm (8.7%), and MDC from 10.5 bpm (5.6%) to 17.9 bpm (24.2%), depending on the condition. Correlations ranged from 0.682 to 0.881. The Magene^® shows acceptable agreement with Polar^® H7 during exercise but may lack precision for resting HR monitoring in clinical settings.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261477973"},"PeriodicalIF":1.8,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148860689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning approaches to predict femoral neck T-score and osteopenia/osteoporosis status from wrist accelerometry data.","authors":"Horacio Sanchez-Trigo, Vahid Farrahi, Hugo Gamboa, David Solis-Martín","doi":"10.1177/09544119261484225","DOIUrl":"https://doi.org/10.1177/09544119261484225","url":null,"abstract":"<p><p>Osteoporosis is a prevalent condition with substantial health and economic implications. Although physical activity is associated with bone health, the specific temporal activity patterns related to bone mineral status remain insufficiently understood. This proof-of-concept study evaluated whether convolutional neural networks (CNNs) applied to Gramian Angular Field (GAF) representations of MIMS-derived wrist accelerometry data could predict femoral neck T-score and classify normal bone status versus osteopenia/osteoporosis. Data from 2504 participants in NHANES 2013-2014 were analyzed, including DXA-derived femoral neck measures, age, sex, body mass, and 7 days of wrist-worn accelerometry. Minute-level MIMS data were averaged into 10-min intervals and transformed into seven-channel GAF images. VGG-like and ResNet-like CNNs were trained from scratch using an internal validation set for early stopping and evaluated on a held-out test set. In classification, the VGG model achieved the best CNN performance, with test accuracy of 71.3%, sensitivity of 61.5%, specificity of 77.5%, <i>F</i>1-score of 0.625, and ROC-AUC of 0.780. In regression, the VGG model also performed best among CNNs, with test <i>R</i>² of 0.305, MSE of 1.095, RMSE of 1.047, and MAE of 0.789. Demographic-only baseline models showed comparable or slightly better performance, indicating that age, sex, and body mass carried substantial predictive information. These findings support the feasibility of GAF-CNN modeling of accelerometry-derived activity patterns for bone-health research, while emphasizing the exploratory nature of the approach and the need for further validation.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261484225"},"PeriodicalIF":1.8,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148860682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A machine learning-based framework for individualized physical activity and strength targets related to women's bone health.","authors":"Horacio Sanchez-Trigo, Luís Silva, Nafiseh Mollaei, Hugo Gamboa, Borja Sañudo","doi":"10.1177/09544119261475010","DOIUrl":"https://doi.org/10.1177/09544119261475010","url":null,"abstract":"<p><p>While substantial evidence supports the associations between physical activity and bone health, the present study aims to advance the field by applying a novel, data-driven approach through machine learning techniques. The primary objective was to identify significant predictors of femoral neck bone mineral density (BMD) and to develop an interpretable modeling framework for estimating individualized physical activity and strength targets associated with BMD in women. This study analyzed data from 1205 female participants in the National Health and Nutrition Examination Survey (NHANES) 2013-2014 cohort to examine the relationship between femoral neck BMD and key variables, including age, body mass, grip strength, and physical activity. Machine learning regression models, such as Multiple Linear Regression (MLR) and Random Forest Regression (RFR), were employed to develop an interpretable modeling framework. Shapley Additive exPlanations (SHAP) were used to support interpretation of the nonlinear RFR model and to visualize each predictor's contribution to BMD estimates. The MLR model estimated femoral neck BMD with a test <i>R</i>² of 0.375, RMSE of 0.105 g/cm², and MAE of 0.082 g/cm². The RFR model resulted in a test <i>R</i>² of 0.309, RMSE of 0.111 g/cm², and MAE of 0.086 g/cm². This study illustrates the potential of interpretable machine learning approaches to support individualized, data-driven assessment of physical activity, strength, and BMD. The numerical model developed in this work provides association-based estimates of physical activity and strength targets according to individual characteristics, highlighting its potential for hypothesis generation and future studies on bone health promotion and osteoporosis prevention. Prospective and interventional validation is required before clinical recommendations can be made.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"9544119261475010"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148654143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanical comparison between Y-TZP and titanium dental implants using finite element analysis.","authors":"Melody Chase-Diaz, Bruno Agostinho Hernandez, Pedro Rodrigues Minim, Victor Mosquim, Carlos Eduardo Edwards Rezende, José Henrique Rubo, Edson Antonio Capello Sousa, Ana Flávia Sanches Borges","doi":"10.1177/09544119261467474","DOIUrl":"10.1177/09544119261467474","url":null,"abstract":"<p><p>Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) implants have been proposed as an alternative to titanium (Ti) implants because of their aesthetic and mechanical properties. This in silico study compared the elastic strain distribution of Y-TZP and Ti dental implants under axial and oblique loads using a previously validated finite element model. Two finite element models, with identical geometry, boundary conditions, loading configuration, prosthetic crown, abutment, and screws, and differing only in implant body material, were constructed for biomechanical evaluation. Each model was subjected to a 300 N load applied axially and at 30°, and equivalent, maximum principal, and minimum principal elastic strains were evaluated in the peri-implant bone, implant body, and abutment screw. Under axial loading, peri-implant bone strain patterns were similar between Ti and Y-TZP, with peak equivalent elastic strain values of approximately 5 millistrain. Under oblique loading, the Y-TZP implant showed lower equivalent elastic strain in the implant body than Ti, with values of approximately 1.3 and 3.0 millistrain, respectively. The abutment screw also showed smaller regions of elevated strain in the Y-TZP model. Within the assumptions of this static linear elastic model, implant material stiffness influenced component-level elastic strain distribution, particularly under oblique loading. These numerical findings should not be interpreted as evidence of improved clinical performance, reduced bone resorption, or superior long-term stability. Further studies should include cyclic loading, fracture and fatigue analyses, interface stability, and patient-specific bone conditions.</p>","PeriodicalId":20666,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine","volume":" ","pages":"782-794"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148520746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}