Frontiers in Bioengineering and Biotechnology最新文献

{"title":"Retraction: Disposable polymeric nanostructured plasmonic biosensors for cell culture adhesion monitoring.","authors":"","doi":"10.3389/fbioe.2025.1581078","DOIUrl":"https://doi.org/10.3389/fbioe.2025.1581078","url":null,"abstract":"<p><p>[This retracts the article DOI: 10.3389/fbioe.2021.799325.].</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1581078"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11905389/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the effect of cervical spine bone distribution on fixation in ankylosing spondylitis.","authors":"Beiyang Wang, Jian Tang, Zhiqiang Wang, Chen Deng, Junqiao Lv, Fang Gao, Xiaoyan Xiong, Lin Sun","doi":"10.3389/fbioe.2025.1430047","DOIUrl":"10.3389/fbioe.2025.1430047","url":null,"abstract":"<p><strong>Purpose: </strong>The distribution of cervical bones in ankylosing spondylitis (AS) differs from that of the normal cervical spine. Traditional simulation methods often yield inaccurate results in finite element analysis. The current study aimed to construct ankylosing spondylitis cervical spine fracture (ASCF) models based on Hounsfield Unit (HU) values to analyze the effects of different fixation approaches.</p><p><strong>Methods: </strong>Quantitative HU measurements of cervical vertebrae and lateral masses were obtained from CT scans of 20 patients with AS. A finite element model of ASCF was constructed based on HU values and was compared with a traditional ASCF model from multiple perspectives. Additionally, three ASCF models were used to compare the effects of various fixation approaches. A meta-analysis of screw loosening rates was conducted to further validate the efficacy of the models.</p><p><strong>Results: </strong>The HU value of the cervical lateral mass in AS is higher than the corresponding mass in the vertebral body. Finite element analysis results indicated that the anterior approach is less stable compared to other approaches, as evidenced by the maximum stress (MS) value of the screw and the maximum displacement (MD) of the entire model. These findings were corroborated by the meta-analysis of screw loosening rates in ASCF.</p><p><strong>Conclusion: </strong>ASCF exhibits an uneven distribution of cervical bone, with more severe osteoporosis in the anterior cervical spine. Consequently, simple anterior approaches to fixation may lead to screw loosening in ASCF.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1430047"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11903474/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ChMER: an exoskeleton robot with active body weight support walker based on compliant actuation for children with cerebral palsy.","authors":"Yuantao Ding, Zhengtao Wang, Peizhong Yang, Suiran Yu","doi":"10.3389/fbioe.2025.1551039","DOIUrl":"10.3389/fbioe.2025.1551039","url":null,"abstract":"<p><strong>Introduction: </strong>Lower limb exoskeleton robots for young children with cerebral palsy (CP) are crucial to support earlier rehabilitation that is more beneficial than later. For safety reasons, pediatric exoskeletons are usually equipped with body weight support (BWS) devices to help young patients maintain balance. However, existing pediatric exoskeletons tend to use stiff joint actuation and passive BWS with limited compliance.</p><p><strong>Method: </strong>This paper proposes a novel mobile exoskeleton robot for young children (3- ∼ 6-years-old) with CP based on intrinsically compliant actuation. A compact kinematic chain that integrates an exoskeleton, an active BWS system, and a walker is proposed. Furthermore, with the actuation design optimization of the kinematic chain, the robot can walk alone stably in passive rehabilitation and provide high compliance in active rehabilitation. The exoskeleton adopts actuation similar to the quasi-direct drive paradigm to acquire high mechanical compliance and uses a secondary planetary reducer to ensure high output torque. Assistive torque control is achieved through proprioceptive sensing instead of torque sensors. The BWS system uses a series elastic actuator to accurately generate the weight support force and significantly reduce the fluctuation of the support force compared to the passive BWS.</p><p><strong>Results and discussion: </strong>Finally, control frameworks for passive and active rehabilitation are implemented to validate the robot performance. The experimental results demonstrate that our robot can support safe and compliant rehabilitation.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1551039"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11903726/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statistical shape modeling of shape variability of the human distal tibia: implication for implant design of the tibial component for total ankle replacement.","authors":"Jian Yu, Chengke Li, Jinyang Lyu, Shengxuan Cao, Chao Zhang, Xin Ma, Dahang Zhao","doi":"10.3389/fbioe.2025.1504897","DOIUrl":"10.3389/fbioe.2025.1504897","url":null,"abstract":"<p><strong>Introduction: </strong>Understanding the morphological variability of the distal tibia can help design tibial components of total ankle implants. This study aimed to assess the shape variability of the distal tibial bone, utilizing the statistical shape modeling (SSM) technique.</p><p><strong>Methods: </strong>A total of 229 tibial bones were analyzed through CT scans to develop SSM models. Principal component analysis (PCA) was employed to characterize shape variation across the male, female, and overall groups. The geometric parameters of the resected surfaces at the 10-mm level above the distal tibial articular surface were compared.</p><p><strong>Results: </strong>The first seven principal component analysis (PCA) modes accounted for approximately 24.9%-40% of the shape variation, totaling 71.5%-75.6%. Considerable variabilities were observed among these three groups and all principal modes of variation. Notably, the male tibia had a bigger medial malleolus, anterior part of the fibular notch, and posterior malleolus. In the 10-mm resection surface of the distal tibia, anterior-posterior and medial-lateral distances were the main sources of variation. In addition, variations were frequently detected at both the anterior and posterior corners of the fibular notch in the resection surface of the distal tibia.</p><p><strong>Conclusion: </strong>The SSM technique has been shown to be an effective method in finding mean shape and principal variability. Size plays a crucial role in both inter- and intra-groups, and morphological differences vary across different sizes. Therefore, these considerations should be taken into account while designing tibial components for total ankle implants.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1504897"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11903760/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel fluorescein sodium-based screening platform for the identification of sphingoid base-producing <i>Wickerhamomyces ciferrii</i> mutants.","authors":"Jun Su Kang, Seong-Rae Lee, Minju Lee, Eunha Kim, Pyung Cheon Lee","doi":"10.3389/fbioe.2025.1548051","DOIUrl":"10.3389/fbioe.2025.1548051","url":null,"abstract":"<p><p>The efficient identification of microbial strains capable of producing rare sphingoid bases, such as sphingosine and sphinganine, is critical for advancing microbial fermentation processes and addressing increasing industrial demands. <i>Wickerhamomyces ciferrii</i>, a non-conventional yeast, naturally overproduces tetraacetyl phytosphingosine (TAPS); however, the production of other valuable sphingoid bases, including sphingosine, sphinganine, and triacetyl sphingosine, remains a key target. In this study, we developed a novel screening method utilizing fluorescein sodium, a selective fluorescent dye that specifically reacts with non-acetylated sphingoid bases-sphinganine, sphingosine, and phytosphingosine-while exhibiting no reactivity with TAPS. A mutant library of <i>W. ciferrii</i> was generated via gamma-ray mutagenesis and screened using fluorescence-activated cell sorting (FACS). Mutants exhibiting high fluorescence intensity, indicative of non-acetylated or partially acetylated sphingoid base production, were isolated through three rounds of sorting and further validated via HPLC analysis. This approach successfully identified three mutant strains: P41C3 (sphingosine-producing), M01_5 (sphinganine-producing), and P41E7 (triacetyl sphingosine-producing). Among them, the P41C3 mutant achieved a sphingosine titer of 36.7 mg/L during shake-flask cultivation, accompanied by a significant reduction in TAPS production, indicating a redirection of metabolic flux. This study demonstrates the utility of fluorescein sodium as a selective screening dye for sphingoid base-producing strains and establishes an effective platform for the metabolic engineering of <i>W. ciferrii</i> to enhance the production of industrially significant sphingolipids.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1548051"},"PeriodicalIF":4.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11897276/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Defining optimal electrospun membranes to enhance biological activities of human endometrial MSCs.","authors":"Jiangru An, Tianyi Ma, Qiuhua Wang, Jinyi Zhang, J Paul Santerre, Wenshuang Wang, Peng Ma, Xiaoqing Zhang","doi":"10.3389/fbioe.2025.1551791","DOIUrl":"10.3389/fbioe.2025.1551791","url":null,"abstract":"<p><strong>Introduction: </strong>Human endometrial mesenchymal stem cells (H-EMSCs) can inhibit endometrial fibrosis and repair damaged endometrium. However, direct cell injection into dam-aged endometrium shows limited cell survival. Cell seeding onto biomaterial-based electrospun membranes could improve H-EMSCs' survival and prolong their stay at the damaged endometrium. Polycaprolactone (PCL), silk fibroin (SF) and hyaluronic acid (HA) are synthetic or natural biomaterials used by the biomedicine field, however, their effects on the biological activities of H-EMSCs remain unclear.</p><p><strong>Methods: </strong>In this study, CD90⁺CD73⁺CD45^- H-EMSCs were extracted from human endometrium and H-EMSCs showed enhanced adhesion, proliferation on PCL-HA vs. PCL, PCL-SF, establishing the potential of the composite to address cell survival issues.</p><p><strong>Results: </strong>H-EMSCs cultured on PCL-HA showed decreased IL-6 gene expression and increased IL-10, VEGFA, TGF-β gene expression vs. PCL-SF, establishing the potential to create a favorable micro-environment for generating vascularized endometrial tissues. PCL, PCL-SF, PCL-HA all supported CD90 and Meflin expression of the seeded H-EMSCs, establishing PCL as a platform to form enhanced biomaterial composites for endometrial repair in the future.</p><p><strong>Discussion: </strong>This study provided significant evidence sup-porting the potential of appropriately tailored composites of PCL and HA to moder-ate inflammation and wound-healing, which can be applied for endometrial tissue repair and regeneration.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1551791"},"PeriodicalIF":4.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11896994/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling the impact of laser refractive surgery on corneal ectasia: an <i>in silico</i> study.","authors":"Benedetta Fantaci, José Félix Rodriguez Matas, Vittoria Squartecchia, Lucia Vavassori, Begoña Calvo","doi":"10.3389/fbioe.2025.1548539","DOIUrl":"10.3389/fbioe.2025.1548539","url":null,"abstract":"<p><strong>Introduction: </strong>Laser refractive surgeries are a safe option for low-to-moderate refractive corrections, providing excellent visual outcomes. Over the years, various procedures have been introduced into clinical practice, but the most performed today remain Photorefractive Keratectomy (PRK), Laser <i>In-Situ</i> Keratomileusis (LASIK), and Small Incision Lenticule Extraction (SMILE). Although laser refractive treatments are considered safe, clinicians have focused on the risk of post-surgical ectasia, a rare but serious complication. Ectasia is characterized by progressive corneal thinning and steepening, leading to vision distortion, irregular astigmatism, and in some cases, a reduction of visual acuity. It is still debated whether laser refractive surgeries can cause ectasia as an iatrogenic condition or merely accelerate the progression of an underlying corneal pathology, not detected during pre-surgical screening. The proposed work investigates the relationship among three laser refractive surgeries (PRK, LASIK and SMILE), currently performed in clinical practice, and ectasia onset and progression by means of an <i>in silico</i> analysis.</p><p><strong>Methods: </strong>An average 3D finite-element corneal model is developed and a pathological area, characterized by reduced stiffness of varying severity grades, is defined to analyze its influence on ectasia development and progression in the pre-surgical state. Three laser treatments (PRK, LASIK and SMILE) are simulated on healthy and pathological models. Pre- and post-surgical conditions are compared to check whether any procedure worsens the pre-surgical pathological state. The optomechanical effect of each procedure on the cornea is analyzed at both healthy and pathological conditions and compared to establish which refractive procedure mostly affects corneal structure.</p><p><strong>Results and discussion: </strong>While the three refractive procedures showed different behaviors in terms of mechanical changes affecting the cornea, from an optical perspective, as the pathology severity worsened, none of the surgeries caused a worsening in the cone's severity with respect to pre-surgical pathological conditions. This result suggests that surgeries may have a limited role in causing post-surgical ectasia, as it seems more plausible that they accelerate the progression of an underlying pathological condition. Among the three procedures, PRK was found to be the least invasive treatment from a mechanical perspective, while SMILE showed the greatest impact on the posterior surface, suggesting a potential long-term risk for ectasia progression.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1548539"},"PeriodicalIF":4.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11897516/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Burn inhalation injury and intubation with dexamethasone-eluting endotracheal tubes modulate local microbiome and alter airway inflammation.","authors":"Gabriela Gonzales, Ronit Malka, Rena Bizios, Gregory R Dion, Teja Guda","doi":"10.3389/fbioe.2025.1524013","DOIUrl":"10.3389/fbioe.2025.1524013","url":null,"abstract":"<p><strong>Background: </strong>Inhalation injuries, caused by exposure to extreme heat and chemical irritants, lead to complications with speaking, swallowing, and breathing. This study investigates the effects of thermal injury and endotracheal tube (ETT) placement on the airway microbiome and inflammatory response. A secondary aim is to assess the impact of localized dexamethasone delivery via a drug-eluting ETT to reduce laryngeal scarring.</p><p><strong>Methods: </strong>Inhalation injury was developed in swine by administering heated air (150°C-160°C) under endoscopic visualization. Following injury, segments of regular or dexamethasone-loaded endotracheal tubes (ETTs) were placed in the injured airways for 3 or 7 days. Computed tomography (CT) scans were used to assess airway narrowing post-injury. Biofilm formation on the ETTs was investigated using micro-CT and microscopy. The airway microbiome was analyzed via 16S rRNA sequencing. Inflammatory markers were quantified using an immunoassay and macrophage populations in laryngeal tissue were assessed with CD86 and CD206 staining. Tracheal tissues were also histologically examined for epithelial thickness, collagen area, and mucin production.</p><p><strong>Results: </strong>CT scans confirmed airway narrowing post-injury, particularly around ETT sites. Biofilm formation was more extensive on dexamethasone-coated ETTs at later timepoints. Beta diversity analysis revealed significant shifts in microbial composition related to ETT type (R² = 0.04, p < 0.05) and duration of placement (R² = 0.22, p < 0.05). Differential abundance analysis demonstrated significant positive log fold changes in genera such as <i>Bergeriella</i>, <i>Peptostreptococcus,</i> and <i>Bacteriodes</i> with thermal injury over time. Inflammatory markers IFN-γ, IL-4, and IL-1β were elevated in dexamethasone-ETT groups at 3 days, then decreased by 7 days. Macrophage markers CD86 and CD206 were significantly greater in dexamethasone groups compared to regular ETT groups at 7 days (p = 0.002 and p = 0.0213, respectively). Epithelial thickness was significantly greater with regular ETT placement compared to dexamethasone ETT placement in the burn-injured airway at 3 days (p = 0.027).</p><p><strong>Conclusion: </strong>Thermal inhalation injury and ETT placement significantly impact airway inflammation, structural integrity, and microbiome composition. Dexamethasone-eluting ETTs, intended to reduce inflammation, increased biofilm formation and elevated cytokine levels, suggesting complex interactions between the drug coating and the host immune response. The airway microbiome shifted significantly with specific taxa thriving in the inflamed environment.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1524013"},"PeriodicalIF":4.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11897493/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The rational design, biofunctionalization and biological properties of orthopedic porous titanium implants: a review.","authors":"Chunliang Guo, Tao Ding, Yuan Cheng, Jianqing Zheng, Xiule Fang, Zhiyun Feng","doi":"10.3389/fbioe.2025.1548675","DOIUrl":"10.3389/fbioe.2025.1548675","url":null,"abstract":"<p><p>Porous titanium implants are becoming an important tool in orthopedic clinical applications. This review provides a comprehensive survey of recent advances in porous titanium implants for orthopedic use. First, the review briefly describes the characteristics of bone and the design requirements of orthopedic implants. Subsequently, the pore size and structural design of porous titanium alloy materials are presented, then we introduce the application of porous titanium alloy implants in orthopedic clinical practice, including spine surgery, joint surgery, and the treatment of bone tumors. Following that, we describe the surface modifications applied to porous titanium implants to obtain better biological functions. Finally, we discuss incorporating environmental responsive mechanisms into porous titanium alloy materials to achieve additional functionalities.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1548675"},"PeriodicalIF":4.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11897010/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanical analysis of maxillary posterior three unit bridge supported misial straight implant and distal tilted implant.","authors":"Guanqi Liu, Shudan Deng, Xiaoyan Chen, Jiahui Lin, Runheng Liu","doi":"10.3389/fbioe.2025.1546656","DOIUrl":"10.3389/fbioe.2025.1546656","url":null,"abstract":"<p><strong>Purpose: </strong>This study aims to investigate the stress distribution in bone tissue, implant, abutment, screw, and bridge restoration when the mesial implant is placed axially and the distal implant is inserted at varying angles in the posterior maxillary region with free-end partial dentition defects, using three-dimensional finite element analysis.</p><p><strong>Materials and methods: </strong>Cone-beam computed-tomography were utilized to create 3D reconstruction models of the maxilla. Stereolithography data of dental implants and accessories were used to design a three-unit full zirconia bridge for the maxillary model. The 3D models were imported into ANSYS Workbench 23.0 software for mesh generation and material property definition. Five different distal implant implantation directions were designed: Inner Tilting 30° group, Inner Tilting 17° group, Parallel group, External Tilting 17° group, and External Tilting 30° group. The models consisted of cortical bone, trabecular bone, implants, abutments, central screws, prosthesis screws, and prostheses. Material properties were assumed to be isotropic, homogeneous, and linearly elastic. The maxillary models were subjected to strict fixation restrictions, and the implants were considered fully osseointegrated. Two loading types were set in ANSYS Workbench 23.0: a vertical load of 300N and a lateral load of 300N at a 45°angle to the implant.</p><p><strong>Results: </strong>Under vertical loading, the parallel group exhibited the lowest maximum stress across all implants, crowns, abutments and screws. Greater tilt angles increased abutment stress, with the external tilting 30° group reaching 1,426 MPa (close to titanium alloy's yield strength). Smaller angles of both external tilting and inner tilting shifted stress to implants from abutment and screw. During lateral loading, the external tilting 30° group showed catastrophic stress escalation (abutment: 8,612 MPa), exceeding titanium's yield limit. Bone stress remained physiological except for the internal tilting 30° group under lateral loading (142 MPa).</p><p><strong>Conclusion: </strong>The parallel group demonstrated the least stress accumulation in all components and bone tissues. Internal tilting of the distal implant is biomechanically preferable to external tilting, and a smaller tilt angle is recommended when external tilting is necessary. This study provides valuable reference data for optimizing implant angulation in patients with the loss of three posterior maxillary teeth, potentially reducing long-term complications associated with implant-fixed bridges.</p>","PeriodicalId":12444,"journal":{"name":"Frontiers in Bioengineering and Biotechnology","volume":"13 ","pages":"1546656"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11893581/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143603561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}