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Martinello PA, Cartagena-Molina AF, Capelletti LK, Fernandes BV, Franco APGDO, Mercuri EGF, Bombarda NHC. Adding mechanobiological cell features to finite element analysis of an immediately loaded dental implant. Eur J Oral Sci 2024:e12992. [PMID: 38771146 DOI: 10.1111/eos.12992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 04/25/2024] [Indexed: 05/22/2024]
Abstract
Finite element analysis (FEA) has been used to analyze the behavior of dental materials, mainly in implantology. However, FEA is a mechanical analysis and few studies have tried to simulate the biological characteristics of the healing process of loaded implants. This study used the rule of mixtures to simulate the biological healing process of immediate implants in an alveolus socket and bone-implant junction interface through FEA. Three-dimensional geometric models of the structures were obtained, and material properties were derived from the literature. The rule of mixtures was used to simulate the healing periods-immediate and early loading, in which the concentration of each cell type, based on in vivo studies, influenced the final elastic moduli. A 100 N occlusal load was simulated in axial and oblique directions. The models were evaluated for maximum and minimum principal strains, and the bone overload was assessed through Frost's mechanostat. There was a higher strain concentration in the healing regions and cortical bone tissue near the cervical portion. The bone overload was higher in the immediate load condition. The method used in this study may help to simulate the biological healing process and could be useful to relate FEA results to clinical practice.
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Affiliation(s)
| | - Andrés Felipe Cartagena-Molina
- Department of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil
- Department of Dentistry, State University of Londrina, Londrina, Paraná, Brazil
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Chen P, Zhang J, Yao J, Hu F, Song L, Yu Y. Effect of angled abutments in the posterior maxillary region on tilted implants: a 3D finite element analysis. Med Biol Eng Comput 2024:10.1007/s11517-024-03081-4. [PMID: 38653881 DOI: 10.1007/s11517-024-03081-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 03/26/2024] [Indexed: 04/25/2024]
Abstract
The aim of this study was to evaluate the bone tissue effects under dynamic loading using finite element analysis (FEA) for four angled abutments with different deviated palatal lateral tilt angles. A three-dimensional model of the posterior maxillary region and an implant crown model were reconstructed and assembled with a three-dimensional model of the implant, angled abutment, and central screw to create a total of 10 three-dimensional finite element models tilted at 15 ∘ , 20 ∘ , 25 ∘ , and 30 ∘ in three groups, and the dynamic loads simulating oral mastication were loaded on the implant crown to analyze the equivalent stresses and strains in the peri-implant bone tissues. Under the dynamic loading, the cortical bone on the buccal side of the implant neck showed different degrees of stress concentration, and the cortical bone stress was much higher than the cancellous bone, and the strain concentration area of each model was located in the bone tissue around the implant neck and base. For the use of angular abutment, under the premise that the cortical bone stresses and strains of the 10 models meet the requirements for use, the peak stresses of 2.907 MPa, 3.018 MPa, and 2.164 MPa were achieved by using the 20 ∘ angular abutment to achieve the tilt angles of 20 ∘ , 25 ∘ , and 30 ∘ implantation, which is more advantageous compared with other models.
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Affiliation(s)
- Peng Chen
- School of Mechanical Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Fengxian, 201418, Shanghai, China
| | - Jianguo Zhang
- School of Mechanical Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Fengxian, 201418, Shanghai, China.
| | - Juan Yao
- Department of Stomatology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Xuhui, 200032, Shanghai, China
| | - Fengling Hu
- Department of Stomatology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Xuhui, 200032, Shanghai, China
- Department of Stomatology, Shanghai Geriatric Medical Center, 2560 Chunshen Road, Minhang, 201104, Shanghai, China
| | - Liang Song
- Department of Stomatology, Shanghai Fifth People's Hospital, Fudan University, 801 Heqing Road, Minhang, 200240, Shanghai, China
| | - Youcheng Yu
- Department of Stomatology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Xuhui, 200032, Shanghai, China
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Shen YW, Huang HL, Hsu JT, Fuh LJ. Effects of diameters of implant and abutment screw on stress distribution within dental implant and alveolar bone: A three-dimensional finite element analysis. J Dent Sci 2024; 19:1126-1134. [PMID: 38618121 PMCID: PMC11010681 DOI: 10.1016/j.jds.2023.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/23/2023] [Indexed: 04/16/2024] Open
Abstract
Background/purpose Few studies have investigated the effects of abutment screw diameter in the stress of dental implants and alveolar bones under occlusal forces. In this study, we investigated how variations in implant diameter, abutment screw diameter, and bone condition affect stresses in the abutment screw, implant, and surrounding bone. Materials and methods Three-dimensional finite element (FE) models were fabricated for dental implants with external hex-type abutments measuring 4 and 5 mm in diameter. The models also included abutment screws measuring 2.0 and 2.5 mm in diameter. Each implant model was integrated with the mandibular bone comprising the cortical bone and four types of cancellous bone. In total, 12 finite element models were generated, subjected to three different occlusal forces, and analyzed using FE software to investigate the stress distribution of dental implant and alveolar bone. Results Wider implants demonstrated lower stresses in implant and bone compared with standard-diameter implants. The quality of cancellous bone has a minimal impact on the stress values of the implant, abutment screw, and cortical bone. Regardless of occlusal arrangement or quality of cancellous bone, a consistent pattern emerged: larger abutment screw diameters led to increased stress levels on the screws, while the stress levels in both cortical and cancellous bone showed comparatively minor fluctuations. Conclusion Wider implants tend to have better stress distribution than standard-diameter implants. The potential advantage of augmenting the abutment screw diameter is unfavorable. It may result in elevated stresses in the implant system.
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Affiliation(s)
- Yen-Wen Shen
- School of Dentistry, China Medical University, Taichung, Taiwan
- Department of Dentistry, China Medical University Hospital, Taichung, Taiwan
| | - Heng-Li Huang
- School of Dentistry, China Medical University, Taichung, Taiwan
- Department of Biomedical Engineering, China Medical University, Taichung, Taiwan
- Department of Bioinformatics and Medical Engineering, Asia University. Taichung, Taiwan
| | - Jui-Ting Hsu
- School of Dentistry, China Medical University, Taichung, Taiwan
- Department of Biomedical Engineering, China Medical University, Taichung, Taiwan
| | - Lih-Jyh Fuh
- School of Dentistry, China Medical University, Taichung, Taiwan
- Department of Dentistry, China Medical University Hospital, Taichung, Taiwan
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Ye Z, Ye H, Wu Y, Jiang Z, Yao H, Xu X, Zhang Y, Du W, Li W, Zheng Y, Ye P, Ding X, Wu L. Effect of bone mass density and alveolar bone resorption on stress in implant restoration of free-end edentulous posterior mandible: Finite element analysis of double-factor sensitivity. Ann Anat 2024; 253:152210. [PMID: 38244942 DOI: 10.1016/j.aanat.2024.152210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 12/19/2023] [Accepted: 01/16/2024] [Indexed: 01/22/2024]
Abstract
BACKGROUND Osseous condition of the mandible was regarded as a key factor influencing stability of implants in the early stage. Finite element analysis was used to assess the effect of bone mass density and alveolar bone resorption (double factors) on stress in a four-unit implant restoration of a free-end edentulous posterior mandible. METHODS A 3D finite element model was constructed for a single-sided free-end edentulous mandible (from mandibular first premolar to mandibular second molar) containing threaded dental implants. Mandible sensitivity modes were constructed with different alveolar bone resorption levels for normal conditions as well as mild, moderate and severe periodontitis, respectively. Based on the mass density of cancellous bone for four types of bones as the sensitivity parameter, two implant design modes were constructed: Model A (four-unit fixed bridge supported by three implants, implant positions were 34, 36 and 37) and model B: 34 × 36, 37 (37: a single implant crown) (34 × 36: three-unit fixed bridge supported by two implants, implant positions were 34 and 36). A total of 32 sensitivity-based finite element models, grouped in two groups, were constructed. Stress distribution and maximum von Mises stress on cortical bone and cancellous bone around the implant, as well as the surface of implant were investigated by using ABAQUS when vertical loading and 45° oblique loading were applied, respectively. RESULTS When vertical loading was applied on the implant, maximum von Mises stress on the cortical bone around the implant was assessed to be 4.726 MPa - 13.15 MPa and 6.254 MPa - 13.79 MPa for groups A and B, respectively; maximum stress on the cancellous bone around the implant was 2.641 MPa - 3.773 MPa and 2.864 MPa - 4.605 MPa, respectively; maximum stress on the surface of implant was 14.7 MPa - 21.17 MPa and 21.64 MPa - 30.70 MPa, respectively. When 45° oblique loading was applied on the implant restoration, maximum von Mises stress on the cortical bone around the implant was assessed to be 42.08 MPa - 92.71 MPa and 50.84 MPa - 102.5 MPa for groups A and B, respectively; maximum stress on the cancellous bone around the implant was 4.88 MPa - 25.95 MPa and 5.227 MPa - 28.43 MPa, respectively; maximum stress on the surface of implant was 77.91 MPa - 124.8 MPa and 109.2 MPa - 150.7 MPa, respectively. Stress peak on the cortical bone and that on cancellous bone around the implant increased and decreased with the decrease in bone mass density, respectively. Stress peak on alveolar bone increased with alveolar bone resorption when oblique loading was applied. CONCLUSION 1. Both alveolar bone resorption and bone mass density (double factors) are critical to implant restoration. Bone mass density may exhibit a more pronounced impact than alveolar bone resorption. 2. From the biomechanical perspective, types I and II bones are preferred for implant restoration, while implantation should be considered carefully in the case of type III bones, or those with less bone mass density accompanied by moderate to severe alveolar bone loss. 3. Splinting crowns restoration is biomechanically superior to single crown restoration.
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Affiliation(s)
- Zhangyan Ye
- Department of Stomatology, The People's Hospital of Pingyang (Pingyang Hospital of Wenzhou Medical University), Wenzhou, Zhejiang 325400, PR China; Institute of Digitized Medicine and Intelligent Technology, Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Hao Ye
- Institute of Digitized Medicine and Intelligent Technology, Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Yue Wu
- City Institute, Dalian University of Technology, Dalian, Liaoning 116600, PR China
| | - Zhengting Jiang
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Huiyu Yao
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Xiaomin Xu
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Yitian Zhang
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Weifeng Du
- Institute of Digitized Medicine and Intelligent Technology, Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Wenshan Li
- Institute of Digitized Medicine and Intelligent Technology, Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Yuwei Zheng
- Institute of Digitized Medicine and Intelligent Technology, Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Pengcheng Ye
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China
| | - Xi Ding
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China.
| | - Lijun Wu
- Institute of Digitized Medicine and Intelligent Technology, Wenzhou Medical University, Wenzhou, Zhejiang 325015, PR China.
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Jemaa H, Eisenburger M, Greuling A. Automated Remodelling of Connectors in Fixed Partial Dentures. Dent J (Basel) 2023; 11:252. [PMID: 37999016 PMCID: PMC10669984 DOI: 10.3390/dj11110252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/13/2023] [Accepted: 10/26/2023] [Indexed: 11/25/2023] Open
Abstract
In this study, an approach for automated parametric remodelling of the connector cross-sectional area in a CAD model of a given fixed partial denture (FPD) geometry was developed and then applied to a 4-unit FPD. The remodelling algorithm was implemented using Rhinoceros and the Grasshopper plugin. The generated CAD models were used to perform a finite element analysis with Ansys to analyse the stress distribution in an implant-supported 4-unit FPD for different connector designs. The results showed that the type of connector adjustment matters and that the resulting stress can be significantly different even for connectors with the same cross-sectional area. For tensile stresses, a reduction in the connector cross-sectional area from the gingival side showed the highest influence on each connector type. It can be concluded that the developed algorithm is suitable for automatic connector detection and adjustment.
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Affiliation(s)
| | | | - Andreas Greuling
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany; (H.J.); (M.E.)
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Qin S, Gao Z. Comparative evaluation of short or standard implants with different prosthetic designs in the posterior mandibular region: a three-dimensional finite element analysis study. Comput Methods Biomech Biomed Engin 2023; 26:1499-1509. [PMID: 36125258 DOI: 10.1080/10255842.2022.2124859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 08/29/2022] [Accepted: 09/11/2022] [Indexed: 11/03/2022]
Abstract
The purpose of this study is to evaluate the stress distribution of splinted or nonsplinted restorations supported by 2 short or 2 standard dental implants in the mandibular molar region using three-dimensional finite element analysis. Two standard implants (4.8 × 10mm) were placed in the mandibular molar area. Two short implants (4.8 × 6 mm) were located in the mandibular molar atrophied area. Implant-supported prostheses were simulated with splinted or nonsplinted crowns design. Vertical load of 200 N and oblique load of 100 N were applied on the central fossa and the buccal cusps. Evaluation of stress distribution in implants and peri-implant cortical bone using the finite element analysis software (Ansys, Version 2020, R2), a multipurpose computer design program. The maximum principal stress of cortical bone around the implants was higher in nonsplinted crowns when compared to splinted crowns. The stress concentration of cortical bone surrounding implants increased as the implant length decreased either splinted crowns or nonsplinted crowns. The short implants with nonsplinted crowns showed lower stresses when compared to standard implants with nonsplinted crowns. The results suggest that the nonsplinted prostheses supported by short dental implants might be considered in the molar area of the atrophic mandible.
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Affiliation(s)
- Siqi Qin
- Department of Stomatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Zhi Gao
- Department of Stomatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
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Talreja KS, Rodrigues SJ, Pai UY, Shetty T, Saldanha S, Mahesh M, Hegde P, Shenoy SB, Naik N, Mukherjee S, Sales A, Kamath V, Bajantri P. A Nonlinear Three-Dimensional Finite Element Analysis of Stress Distribution and Microstrain Evaluation in Short Dental Implants with Three Different Implant-Abutment Connections in Single and Splinted Conditions in the Posterior Mandible. Int J Dent 2023; 2023:8851098. [PMID: 37885810 PMCID: PMC10599862 DOI: 10.1155/2023/8851098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/10/2023] [Accepted: 06/24/2023] [Indexed: 10/28/2023] Open
Abstract
Background Stress distribution plays a vital role in the longevity and success of implant-supported prosthesis. This study evaluated the von Mises stress and microstrain in the peri-implant bone and the implant-abutment junction of short dental implants with three different implant-abutment connections in splinted and unsplinted conditions using finite element analysis (FEA). Materials and Methods In this experimental study, nine transversely isotropic finite element models were developed, and randomly divided into three equal groups (n = 3): control, (Group AC) single-standard 4.3 × 10 mm bone level implant-supported restorations with external hexagonal (EH) connection, internal conical (IC) and internal trichannel (ITC) connection, single short implant-supported restorations (Group AT), and splinted short implant-supported restorations (Group B) for each of the three implant-abutment connections, respectively. A 200 N load was applied along the long axis of the implants and a 100 N (45°) oblique load was applied and von Mises stress and microstrain values were evaluated. Results Single standard implants demonstrated the highest von Mises stress and microstrain values followed by single short implants and splinted short implants, respectively. Among the implant-abutment connections, the IC connection showed the highest values and the ITC connection showed the least values. Conclusion Within the limitations of this study, it was concluded that splinting of short dental implants demonstrated lesser and more homogeneous stress and microstrain, especially on oblique loading. The microstrain values for all connections evaluated were within the physiological loading limit (200-2,500 N) and were hence considered safe for clinical use.
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Affiliation(s)
- Karishma S. Talreja
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Shobha J. Rodrigues
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Umesh Y. Pai
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Thilak Shetty
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Sharon Saldanha
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - M. Mahesh
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Puneeth Hegde
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Satish B. Shenoy
- Department of Aeronautical and Automobile Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Nithesh Naik
- Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Sandipan Mukherjee
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Ann Sales
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Vignesh Kamath
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Prashant Bajantri
- Department of Prosthodontics and Crown and Bridge, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
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Martins RG, Castro TSD, Dib LL, Gehrke SA, Mesquita AMM. Influence of Restorative Material on the Distribution of Loads to the Bone in Hybrid Abutment Crowns-In Vitro Study. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1188. [PMID: 37512000 PMCID: PMC10384236 DOI: 10.3390/medicina59071188] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/05/2023] [Accepted: 06/15/2023] [Indexed: 07/30/2023]
Abstract
Background: The objective of this study was to evaluate the load transmitted to the peri-implant bone by seven different restorative materials in single-unit rehabilitations with morse taper implants using a strain gauge. Materials: In a polyurethane block that simulated type III bone, a morse taper platform implant was installed (3.5 × 11 mm) in the center and 1 mm below the test base surface, and four strain gauges were installed around the implant, simulating the mesial, distal, buccal and lingual positions. Seven similar hybrid abutment crowns were crafted to simulate a lower premolar using different materials: 1-PMMA; 2-glass ceramic over resin matrix; 3-PEEK + lithium disilicate; 4-metal-ceramic; 5-lithium disilicate; 6-zirconia + feldspathic; 7-monolithic zirconia. All groups underwent axial and oblique loads (45 degrees) of 150 N from a universal testing machine. Five measurements (n = 5) were performed with each material and for each load type; the microdeformation data underwent statistical analysis. The data were obtained in microdeformation (με), and the significance level was set at p ≤ 0.05. Results: There was no statistically significant difference in the evaluation among the materials under either the axial load or the oblique load at 45 degrees. In turn, in the comparison between axial load and oblique load, there was a difference in load for all materials. Conclusion: The restorative material did not influence the load transmitted to the bone. Furthermore, the load transmitted to the bone was greater when it occurred obliquely at 45° regardless of the material used. In conclusion, it appeared that the different elastic modulus of each material did not influence the load transmission to the peri-implant bone.
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Affiliation(s)
| | | | - Luciano Lauria Dib
- Department of Implantology, Paulista University-UNIP, São Paulo 04026-002, Brazil
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Latifi F, Tabrizi R, Hosseinikordkheili M. How does the Number of Implants Affect Stress Distribution in Fibula Graft at the Posterior of the Mandible? A Finite Element Analysis. J Maxillofac Oral Surg 2023; 22:304-312. [PMID: 37122787 PMCID: PMC10130298 DOI: 10.1007/s12663-022-01743-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 05/26/2022] [Indexed: 10/17/2022] Open
Abstract
Objectives Evidence about the implant protocol and success in the osseous microvascular grafts is not sufficient. Stress distribution around dental implants is one of the important factors determining treatment success. The purpose of this study was to evaluate stress distribution in the bone supporting the implants inserted in the fibula free flap, in patients with large defects in the posterior of the mandible by finite element analysis (FEA). Materials and Methods The CBCT was obtained from one patient with fibula free flap in the posterior of the mandible and also from a 4.1 × 10 mm implant (Zimmer, Zimmer dental, Carlsbad, USA). Two 3D finite models were designed containing three or four implants. The implants were splinted by a suprastructure. Vertical load (300 N) and oblique load (50 N) were applied to the suprastructure. The von Mises stress distribution and the micromotion of implants were evaluated. Results No significant difference was observed between implants micromotion in two models. According to stress distribution analysis and determining maximum stress regions, the model with four implants imposes more stress on titanium components and surrounding bone. Conclusion The stress distribution around the implants of mandibular models with posterior defect that was reconstructed with fibula free flap is better in models with three fixtures versus four fixtures.
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Affiliation(s)
- Fatemeh Latifi
- Department of Oral and Maxillofacial Surgery, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Tabrizi
- Department of Oral and Maxillofacial Surgery, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Nie H, Tang Y, Yang Y, Wu W, Zhou W, Liu Z. Influence of a new abutment design concept on the biomechanics of peri-implant bone, implant components, and microgap formation: a finite element analysis. BMC Oral Health 2023; 23:277. [PMID: 37170117 PMCID: PMC10176806 DOI: 10.1186/s12903-023-02989-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/25/2023] [Indexed: 05/13/2023] Open
Abstract
BACKGROUND A new two-piece abutment design consisting of an upper prosthetic component and tissue-level base has been introduced; however, the biomechanical behavior of such a design has not been documented. This study aimed to investigate the effect of a two-piece abutment design on the stress in the implant components and surrounding bone, as well as its influence on microgap formation. METHODS To simulate the implant models in the mandibular left first molar area, we established nine experimental groups that included three bone qualities (type II, III, and IV) and three implant-abutment designs (internal bone level, tissue level, and a two-piece design). After the screw was preloaded, the maximum occlusal (600 N) and masticatory (225 N) forces were established. Finite element analysis was performed to analyze the maximum and minimum principal stresses on the peri-implant bone; the von Mises stresses in the implants, abutments, bases, and screws, and the microgaps at the implant-abutment, implant-base, and base-abutment interfaces. RESULTS For all three loading methods, the two-piece abutment design and bone-level connection exhibited similarities in the maximum and minimum principal stresses in the peri-implant bone. The von Mises stresses in both screws and bases were greater for the two-piece design than for the other connection types. The smallest microgap was detected in the tissue-level connection; the largest was observed at the implant-base interface in the two-piece design. CONCLUSIONS The present study found no evidence that the abutment design exerts a significant effect on peri-implant bone stress. However, the mechanical effects associated with the base and screws should be noted when using a two-piece abutment design. The two-piece abutment design also had no advantage in eliminating the microgap.
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Affiliation(s)
- Huimin Nie
- Department of Implant Dentistry, Binzhou Medical University Affiliated Yantai Stomatological Hospital, No. 19, Beima Road, Zhifu District, Yantai, 264000, China
| | - Yantai Tang
- Department of Implant Dentistry, Binzhou Medical University Affiliated Yantai Stomatological Hospital, No. 19, Beima Road, Zhifu District, Yantai, 264000, China
| | - Yan Yang
- Department of Implant Dentistry, Binzhou Medical University Affiliated Yantai Stomatological Hospital, No. 19, Beima Road, Zhifu District, Yantai, 264000, China
| | - Weijie Wu
- University of Science and Technology Beijing, Beijing, 100000, China
| | - Wenjuan Zhou
- Department of Implant Dentistry, Binzhou Medical University Affiliated Yantai Stomatological Hospital, No. 19, Beima Road, Zhifu District, Yantai, 264000, China.
| | - Zhonghao Liu
- Department of Implant Dentistry, Binzhou Medical University Affiliated Yantai Stomatological Hospital, No. 19, Beima Road, Zhifu District, Yantai, 264000, China
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11
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The evaluation of stress on bone level and tissue level short implants: A Finite Element Analysis (FEA) study. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2023; 124:101298. [PMID: 36179771 DOI: 10.1016/j.jormas.2022.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/23/2022]
Abstract
PURPOSE This study aimed to evaluate the difference between the stress level and distribution around the BL and TL short implants, and their surrounding structures, using finite element analysis. METHODS Two different study models were constructed: BL model and TL model. Two dental implant systems (ITI (Straumann, Waldenburg, Switzerland) and NTA Short) with a diameter of 4.1 mm and 4 mm and with a length of 6 mm were used in this study. In each model, implants were placed in the mandibular 1st molar region. The von Mises stress and maximum principal (tensile) and minimum principal (compressive) stresses were evaluated. RESULTS The highest stress values recorded in the BL implants (von Mises: 342.77 MPa), in the peri‑implant bone around the BL implants (maximum principal stress: 114.1 MPa), as a result of oblique loading, and overall stress values were found to be higher in the BL model. However, these measured values appeared to be low to cause a fracture, when considering the yield strengths of the materials and bone. CONCLUSIONS The stress values were higher in the BL model, but not high enough to cause failure. Short implants could be an effective method of treatment for patients unsuitable for advanced surgical techniques.
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Tak S, Noh G, Jeong Y, Lee H. Automated vector analysis to design implant-supported prostheses: A dental technique. J Prosthet Dent 2023; 129:257-261. [PMID: 34217508 DOI: 10.1016/j.prosdent.2021.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/20/2021] [Accepted: 05/20/2021] [Indexed: 11/18/2022]
Abstract
The prosthesis loading force is an important factor for dental implant survival. Even if adequate osseointegration of the dental implant has been achieved, if the occlusal forces are not correctly distributed, lateral torque can be generated causing high stress on surrounding tissues. The stress value of implant prostheses could be different whether the direction of load is vertical or oblique, affected by the shape of the occlusal surface. When an implant-supported prosthesis is designed with a dental computer-aided design software program, the average vectors from each occlusal contact point can be visualized. If the visualized vector generates lateral torque, the occlusal surface design can be modified before finalizing the design. The described technique uses automated vector analysis to enable visualization of the occlusal vector to improve prosthesis design, optimizing occlusal forces.
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Affiliation(s)
- Sangmyeong Tak
- Doctoral student, Department of Prosthodontics, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - Gunwoo Noh
- Assistant Professor, School of Mechanical Engineering, Korea University, Seoul, Republic of Korea
| | - Yuwon Jeong
- Researcher, Department of Prosthodontics, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - Hyeonjong Lee
- Assistant Professor, Department of Prosthodontics, Dental Research Institute, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Republic of Korea.
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Uppalapati V, Kumar S, Aggarwal R, Bhat I, Munaganti J, Khan S. Three-dimensional Finite Element Stress Pattern Analysis in Bone around Implant-supported Abutment with Different Angulations under Axial and Oblique Load. J Contemp Dent Pract 2023; 24:16-20. [PMID: 37189007 DOI: 10.5005/jp-journals-10024-3464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
AIM The goal of this research was to compare the stress distribution in the bone adjacent to the implant where three different angled abutments were loaded in both the axial and oblique directions. MATERIALS AND METHODS The premaxilla region was digitally recreated in 3-dimension (3D) using a finite element model, with a solid 4.2 mm by 13 mm implant and abutments at 0°, 15°, and 25° of rotation. Axial load (100 N) and oblique load were also applied to the abutments (178 N). Six models were made and used with a fixed bases. The coefficient of friction was set at a constant value of 0.02. The CITIA program was used for the stress analysis. In this investigation, we employed linear static analysis. Each abutment and crown in the model has subjected to an arbitrary vertical load as well as the oblique load. RESULTS The cortical bone around the implant with a 25° angled abutment experienced a maximum von Mises stress of 187.692 Mpa under oblique load. This stress was increased with the degree of abutment angulation. CONCLUSION As abutment angulation was increased, axial and oblique burdens were also increased. In both cases, we were able to identify the source of the observed growth. When we looked at the effect of stress on angulation, we found that the peaks were seen in the area of abutment and cortical bone. Since it was difficult to predict the stress distribution around implants with varying abutment angles in a clinical setting, finite element analysis (FEA) was chosen for this investigation as a more cutting-edge approach. CLINICAL SIGNIFICANCE It is a herculean task calculating the prompted forces clinically, FEA has opted for this study as it's a progressively wielded tool to prognosticate the stress allocation in the region of the implants with different angled abutments.
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Affiliation(s)
- Vinutna Uppalapati
- Department of Prosthodontics including Crown and Bridge, Surendera Dental College and Research Institute, Rajasthan University of Health Sciences, Sri Ganganagar, Rajasthan, India
| | - Sandeep Kumar
- Department of Prosthodontics including Crown and Bridge, Surendera Dental College and Research Institute, Rajasthan University of Health Sciences, Sri Ganganagar, Rajasthan, India, Phone: +91 9024606318, e-mail:
| | - Rajnish Aggarwal
- Department of Prosthodontics including Crown and Bridge, Surendera Dental College and Research Institute, Rajasthan University of Health Sciences, Sri Ganganagar, Rajasthan, India
| | - Ijaz Bhat
- Department of Prosthodontics including Crown and Bridge, Surendera Dental College and Research Institute, Rajasthan University of Health Sciences, Sri Ganganagar, Rajasthan, India
| | - Jagruthi Munaganti
- Department of Prosthodontics including Crown and Bridge, Surendera Dental College and Research Institute, Rajasthan University of Health Sciences, Sri Ganganagar, Rajasthan, India
| | - Saiba Khan
- Department of Prosthodontics including Crown and Bridge, Surendera Dental College and Research Institute, Rajasthan University of Health Sciences, Sri Ganganagar, Rajasthan, India
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Akin R, Chapple AG. Clinical Advantages of Immediate Posterior Implants With Custom Healing Abutments: Up to 8-Year Follow-Up of 115 Cases. J Oral Maxillofac Surg 2022; 80:1952-1965. [PMID: 36155739 DOI: 10.1016/j.joms.2022.08.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 08/22/2022] [Accepted: 08/22/2022] [Indexed: 11/18/2022]
Abstract
PURPOSE Proper management of the soft tissues around dental implants is crucial to their long-term function and esthetics. The purpose of this article is to report the survival rate of immediate posterior implants when using an immediate chair-side technique for custom healing abutments. MATERIALS AND METHODS The investigator implemented a retrospective case series analysis of a sample of 115 consecutive patients with 1 posterior dental implant placed between February 1, 2012 and December 9, 2014, in the author's private practice who underwent the previously published technique for immediate custom chair-side healing abutment fabrication. In this descriptive analysis, the primary outcome variable was implant survival. Other variables included patient gender and age. RESULTS Of the 115 patients in this cohort, 66 were female and 49 were male, with a mean age of 58 years, with 73% of the sites being first molars and 27% second molars. This study sample had a 98.26% overall implant survival rate with 3 implant failures. Median follow-up time was 1 year with identical 1-year and 5-year survival rates. Follow-up at up to 8 years demonstrated a 98.26% overall survival rate with 100% survival in the maxilla and 96.08% in the mandible. CONCLUSIONS This case series demonstrates that the Anatomic Harmony Abutment technique, by applying principles of flapless posterior immediate implant surgery with immediate custom healing abutment placement, can lead to highly successful implant outcomes.
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Affiliation(s)
- Richard Akin
- Board Certified Oral and Maxillofacial Surgeon, Clinical Assistant Professor, LSU Health Sciences Center, Private Practice, Baton Rouge, LA.
| | - Andrew G Chapple
- Biostatistics Assistant Professor, School of Public Health, LSU Health Sciences Center, New Orleans, LA
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Guo F, Huang S, Liu N, Hu M, Shi C, Li D, Liu C. Evaluation of the mechanical properties and fit of 3D-printed polyetheretherketone removable partial dentures. Dent Mater J 2022; 41:816-823. [PMID: 35858792 DOI: 10.4012/dmj.2022-063] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Compared with CAD/CAM, fused deposition modeling (FDM) 3D printing technology is simple and safe to operate and has a low cost and high material utilization rate; thus, it is widely used. The present investigation aimed to evaluate the mechanical properties and fit of polyetheretherketone (PEEK) removable partial dentures (RPDs) constructed by FDM. We analyzed mechanical properties of PEEK samples prepared by FDM, milling, or injection molding. RPDs were designed and finite element analysis models was constructed to evaluate maximum stress and strain in the RPDs, cortical bone and mucosa. Geomagic Qualify software was used to analyze gaps between the model and the tissue surface of the framework. The results showed that the compressive strength of the 3D-printed PRDs was greater than that of the injection-molded samples. Finite element analysis demonstrated that the maximum stress on the PRDs was less than the yield strength of the material. Overall, the mechanical properties and fit of the PEEK RPD fabricated by FDM technology essentially fulfilled clinical requirements.
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Affiliation(s)
- Fang Guo
- Department of Oral and Maxillofacial Surgery, School of Stomatology, Xi'an Medical University
| | - Shuo Huang
- Department of Oral and Maxillofacial Surgery, School of Stomatology, Xi'an Medical University
| | - Ning Liu
- Department of Oral and Maxillofacial Surgery, School of Stomatology, Xi'an Medical University
| | - Min Hu
- Department of Oral and Maxillofacial Surgery, General Hospital of PLA
| | - Changquan Shi
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiao tong University
| | - Dichen Li
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiao tong University
| | - Changkui Liu
- Department of Oral and Maxillofacial Surgery, School of Stomatology, Xi'an Medical University
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A Finite Element Stress Analysis of a Concical Triangular Connection in Implants: A New Proposal. MATERIALS 2022; 15:ma15103680. [PMID: 35629709 PMCID: PMC9145359 DOI: 10.3390/ma15103680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/21/2022] [Accepted: 05/16/2022] [Indexed: 12/04/2022]
Abstract
Conical implant–abutment connections are popular for their stability; however, in other conditions, such as excessive force, implants and abutments can absorb all the stress. Some connections with three points of support can resist more than conical connections. In recent years, different studies has shown that the design of a connection affects its stability. The aim of this study was to analyze and compare the stresses in finite elements (FEs) in a newly proposed conical triangular connection in implants with hexagonal and conical connections. A nonlinear 3D FE parametric model was developed using SOLIDWORKS 2017®. All the connections, i.e., external and internal hexagons, morse taper, conical connection, and the new conical triangular proposal were compared when axial forces of 150, 250, and 350 N were applied to the occlusal. The maximum stress was found in the external hexagon. The maximum stress was concentrated at the level of the neck of the abutment, implant, and bone, except for the morse taper; at the level of the crown and abutment, the lowest stress occurred in the new proposal. Conclusions: The new conical triangular (CT) connection and the conical connection (CC) generate similar stress in the implant, abutment, and crown. However, the CT connection improves the CC by reducing stress at the bone level, adding an advantage to having three retention points.
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Manchikalapudi G, Basapogu S. Finite Element Analysis of effect of cusp inclination and occlusal contacts in PFM and PEEK implant-supported crowns on resultant stresses. Med J Armed Forces India 2022; 78:80-87. [PMID: 35035048 PMCID: PMC8737102 DOI: 10.1016/j.mjafi.2020.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 11/12/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Effect of prosthesis design on occlusal overload and long-term implant stability cannot be overstated. In Porcelain Fused to Metal (PFM) crowns, low cusp inclination and occlusal contacts limited to central fossa ensure axially directed forces on an implant but often pose esthetic and functional challenges. It is theorized that resilient Polyetheretherketone (PEEK) crowns have shock absorption capacity for favorable stress distribution. This study compared two implant crown materials and evaluated the effect of cusp inclination and occlusal contact distribution on resultant stresses. METHODS Thirty 3D finite element models of implant-supported PFM and PEEK crowns, generated using Solidedge 3D CAD solid modeling software (v19, Siemens PLM Software Inc.,US), were used to study the effect of 3 cups inclinations (0°, 15°, 30°) under five load conditions, with 300N force distributed over one, two, or three contact areas and exported to ANSYS (v18.1, ANSYS Inc. Pennsylvania, US) for stress analysis. RESULTS Maximum stress in both PFM and PEEK models was at the neck of the implant under Load 3(300N distributed over three contact areas: central fossa, buccal cusp tip, marginal ridge). Minimum stress in all models was under Load 1(300N applied at one contact area in central fossa). Maximum stresses were recorded for 30° cusp inclination in PFM models. CONCLUSION In both PFM and PEEK crown models, contact areas placed away from the implant axis generated greater implant and peri-implant stresses and had more effect on resultant stresses than that of increase in cusp inclination. The effect of cusp inclination on the resultant stresses was dependent on the crown material.
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Affiliation(s)
- Githanjali Manchikalapudi
- Assistant Professor (Prosthodontics), Government Dental College & Hospital, Hyderabad, Telangana, India,Corresponding author.
| | - Sreeramulu Basapogu
- Professor & Head (Prosthodontics), Government Dental College and Hospital, Hyderabad, Telangana, India
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Evaluation of Stress Distribution during Insertion of Tapered Dental Implants in Various Osteotomy Techniques: Three-Dimensional Finite Element Study. MATERIALS 2021; 14:ma14247547. [PMID: 34947142 PMCID: PMC8704667 DOI: 10.3390/ma14247547] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/27/2021] [Accepted: 11/28/2021] [Indexed: 11/17/2022]
Abstract
Conventional osteotomy techniques can, in some cases, induce higher stress on bone during implant insertion as a result of higher torque. The aim of the present study was to evaluate and compare the stress exerted on the underlying osseous tissues during the insertion of a tapered implant using different osteotomy techniques through a dynamic finite element analysis which has been widely applied to study biomedical problems through computer-aided software. In three different types of osteotomy techniques, namely conventional (B1), bone tap (B2), and countersink (B3), five models and implants designed per technique were prepared, implant insertion was simulated, and stress exerted by the implant during each was evaluated. Comparison of stress scores on the cortical and cancellous bone at different time points and time intervals from initiation of insertion to the final placement of the implant was made. There was a highly statistically significant difference between B1 and B2 (p = 0.0001) and B2 and B3 (p = 0.0001) groups. In contrast, there was no statistically significant difference in the stress scores between B1 and B3 (p = 0.3080) groups at all time points of implant placement. Overall, a highly significant difference was observed between the stresses exerted in each technique. Within the limitations of our study, bone tap significantly exerted lesser stresses on the entire bone than conventional and countersink type of osteotomy procedures. Considering the stress distribution at the crestal region, the countersink showed lower values in comparison to others.
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Roy AK, Dixit N, Punde P, Sinha KT, Jalaluddin M, Kumar A. Stress Distribution in Cortical Bone around the Basal Implant - A Finite Element Analysis. J Pharm Bioallied Sci 2021; 13:S633-S636. [PMID: 34447169 PMCID: PMC8375879 DOI: 10.4103/jpbs.jpbs_679_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 11/04/2022] Open
Abstract
Aim The aim of the study was to develop a model that represents a basal implant with stress distribution in the cortical bone on application of loads emulating masticatory forces. Materials and Methods In this study, the stress distribution in the bone and the implant is evaluated by applying various loads that emulate the masticatory forces. The geometric models of cortical bone representing the premolar area and a basal implant model of the following specifications, longitudinal oval threaded pin (1.95 mm × 2.1/2.3 mm ø), height of the implant head (7.2 mm), and width of the implant head (3.5 mm) (BOI BS, IDHEDENTAL), were generated with Ansys software, and both the implant model and the bone model are superimposed to mimic the bone implant system as a unit. Results Overall comparison of stress distribution on both implant shaft and implant neck showed that maximum stresses are located at implant neck irrespective of forces applied and minimum stresses are located at implant shaft. On overall comparison of stresses seen within the bone and the implant, it was observed that the maximum stresses were seen in the implant neck followed by the implant shaft followed by the bone interface. Conclusion The present study concluded that the stress transmission is greatest during application of oblique load (70 N) followed by horizontal load (10 N) and the least by vertical load (35 N).
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Affiliation(s)
- Anip Kumar Roy
- Department of Prosthodontics, Institute of Dental Sciences, Baeilly, Uttar Pradesh, India
| | - Nivedita Dixit
- Department of Prosthodontics, Institute of Dental Sciences, Baeilly, Uttar Pradesh, India
| | - Prashant Punde
- Department of Oral and Maxillofacial Surgery, School of Dental Sciences, Krishna Institute of Medical Sciences Deemed to be University, Karad, Maharashtra, India
| | - Koshika Tondon Sinha
- Department of Prosthodontics, Purvanchal Institute of Dental Sciences, Gorakhpur, Uttar Pradesh, India
| | - Mohammad Jalaluddin
- Department of Periodontics and Oral Implantology, Kalinga Institute of Dental Sciences, KIIT Deemed to be University, Bhubaneswar, Odisha, India
| | - Ashish Kumar
- Consultant Prosthodontist, Katihar, Bihar, India
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Development of a lead foil crown delineation technique for implant rehabilitations to generate patient specific finite element model of occlusal loading points. MethodsX 2021; 8:101373. [PMID: 34430269 PMCID: PMC8374443 DOI: 10.1016/j.mex.2021.101373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/26/2021] [Indexed: 11/23/2022] Open
Abstract
Understanding the clinical biomechanical basis of dental implant supported functional rehabilitation of edentulous jaws improves precision, longevity and overall success of a planned treatment. Stress distribution pattern around dental implants is an important determinant for rate of bone resorption around them. During planning the treatment for most prosthetic rehabilitations, the surgeon uses a software to virtually plan the dimension, position and angulation of the implants considering only the quantity of available bone in the area of interest but does not usually consider the strain generated around the implants after prosthetically loading them. We hence hypothesise that dental implants not be subjected to abnormal strain they should be positioned and angulated not only based on volume of bone available but also based on the vector of occlusal load. The virtual FEA model to analyse the stress distribution would hence require alveolar bone with future tooth/ teeth in centric relation to be modelled. This paper proposes a simple innovative technique to develop a 3D FE model of occlusal loading surface by using a radio-opaque malleable lead foil to generate a patient specific FE model. This would greatly minimise modelling errors and also help determine the best position of the dental implant based on both the volume of bone in the CT scan and the results of FE analyses.Functional rehabilitation using dental implant supported prosthesis needs to be biomechanically analysed to know and understand the stress distribution pattern around the implant. When teeth (Loading points) are missing, patient specific virtual model of occlusal loading points cannot be generated. ‘Lead foil crown delineation technique’ helps to generate patient specific 3D model of occlusal surface for load application.
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Acharya PH, Patel VV, Duseja SS, Chauhan VR. Comparative evaluation of peri-implant stress distribution in implant protected occlusion and cuspally loaded occlusion on a 3 unit implant supported fixed partial denture: A 3D finite element analysis study. J Adv Prosthodont 2021; 13:79-88. [PMID: 34025956 PMCID: PMC8110741 DOI: 10.4047/jap.2021.13.2.79] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 04/18/2021] [Accepted: 04/23/2021] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To assess peri-implant stress distribution using finite element analysis in implant supported fixed partial denture with occlusal schemes of cuspally loaded occlusion and implant protected occlusion. MATERIALS AND METHODS A 3-D finite element model of mandible with D2 bone with partially edentulism with unilateral distal extension was made. Two Ti alloy identical implants with 4.2 mm diameter and 10 mm length were placed in the mandibular second premolar and the mandibular second molar region and prosthesis was given with the mandibular first molar pontic. Vertical load of 100 N and and oblique load of 70 N was applied on occlusal surface of prosthesis. Group 1 was cuspally loaded occlusion with total 8 contact points and Group 2 was implant protected occlusion with 3 contact points. RESULTS In Group 1 for vertical load , maximum stress was generated over implant having 14.3552 Mpa. While for oblique load, overall stress generated was 28.0732 Mpa. In Group 2 for vertical load, maximum stress was generated over crown and overall stress was 16.7682 Mpa. But for oblique load, crown stress and overall stress was maximum 22.7561 Mpa. When Group 1 is compared to Group 2, harmful oblique load caused maximum overall stress 28.0732 Mpa in Group 1. CONCLUSION In Group 1, vertical load generated high implant stress, and oblique load generated high overall stresses, cortical stresses and crown stresses compared to vertical load. In Group 2, oblique load generated more overall stresses, cortical stresses, and crown stresses compared to vertical load. Implant protected occlusion generated lesser harmful oblique implant, crown, bone and overall stresses compared to cuspally loaded occlusion.
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Bozyel D, Taşar Faruk S. Biomechanical Behavior of All-on-4 and M-4 Configurations in an Atrophic Maxilla: A 3D Finite Element Method. Med Sci Monit 2021; 27:e929908. [PMID: 33774647 PMCID: PMC8015646 DOI: 10.12659/msm.929908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND In edentulous patients, the concept of 4 implants with early loading has been widely used in clinical settings. In the case of bone atrophy in the anterior maxilla, using short implants or an angulated implant may be a good choice for treatment. The occlusal scheme remains a key aspect of All-on-4. The aim of this study was to use the 3-dimensional (3D) finite element method (FEM) to evaluate how different All-on-4 designs for canine-guided and group function occlusion affected the distribution of stress in the atrophic premaxilla. MATERIAL AND METHODS A 3D edentulous maxilla model was created and in 3D FEM, 3 different configurations - M4, All-on-4, and short implant - were modeled by changing the anterior implants and using 2 different occlusal schemes. For each model, the occlusal load was applied to simulate lateral movements. For cortical bone, the maximum and minimum principal stress values were generated, and for ductile materials, von Mises stress values were obtained. RESULTS No significant differences were detected among the models; generally, however, the highest stress values were observed in the M-4 model and the models with short implants. Slightly higher stress values were observed in the group function occlusion group than in the canine-guided occlusion group. CONCLUSIONS To promote better primary stabilization, M-4 or short implant configurations with canine-guided occlusion appear to be preferable for patients who have severe atrophy in the anterior maxilla.
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Affiliation(s)
- Delal Bozyel
- Department of Prosthodontics, Near East University, Nicosia, Cyprus
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Liu CW, Chuang KJ, Chen CT, Lin KC. Evaluation of the Influence of Bone Resorption on Dental Implant Systems Using Taguchi Method and Finite Element Analysis. J BIOMATER TISS ENG 2021. [DOI: 10.1166/jbt.2021.2554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Dental implants are currently the mainstay of dental restoration procedures. They are used to reestablish normal chewing functions for patients. Several studies have reported their high success rate, but post-op bone resorption at the implant site increases the risk of implant fracture,
which is especially significant in the posterior mandibular tooth (PMT) area. This study focused on bone resorption at the PMT area to assess and understand the mechanism of implant failure. This study used three implant systems on the posterior mandibular area. Computer tomography (CT) scans
and reverse engineering were used to construct mandible and implant systems. The Taguchi method and finite element analysis (FEA) were used to explore the role of biting force on the components of various implant systems in the development of bone resorption. The results of this study found
that when the implant site with bone resorption takes a biting force, the stress on the implant is inversely proportional to implant diameter and proportional to its length. For the stress loading, cortical bone thickness does not play a significant role. Instead, the most significant factor
is implant diameter, followed by implant length. For better operation outcomes, it is recommended to use implants of larger diameter and less length. Also, it is recommended to avoid the use of implants less than 4.5 mm in diameter, regardless of the implant system, in order to prevent early
implant damage or fracture due to bone resorption.
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Affiliation(s)
- Chien-Wei Liu
- Department of Information Management, St. Mary's Junior College of Medicine, Nursing and Management, Yilan 266, Taiwan
| | - Kai-Jen Chuang
- Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
| | - Chien-Tsu Chen
- School of Medicine, Taipei Medical University, Taipei 110, Taiwan
| | - Kuan-Chou Lin
- Department of Oral and Maxillofacial Surgery, Wan Fang Hospital, School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan
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de Oliveira JC, Sordi MB, da Cruz ACC, Zanetti RV, Betiol EAG, Vieira SR, Zanetti AL. Number of dental abutments influencing the biomechanical behavior of tooth‒implant-supported fixed partial dentures: A finite element analysis. J Dent Res Dent Clin Dent Prospects 2020; 14:228-234. [PMID: 33575012 PMCID: PMC7867679 DOI: 10.34172/joddd.2020.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 10/21/2020] [Indexed: 11/09/2022] Open
Abstract
Background. Local or systemic issues might prevent installing a sufficient number of dental implants for fixed prosthetic rehabilitation. Splinting dental implants and natural teeth in fixed dentures could overcome such limitations. Therefore, this study aimed to evaluate the influence of the number of dental abutments in the biomechanics of tooth‒implant-supported fixed partial dentures (FPDs). The null hypothesis was that increasing the number of abutment teeth would not decrease the stress over the abutments and surrounding bone. Methods. Left mandibular lateral incisor, canine, premolars, and molars were reconstructed through computed tomography and edited using image processing software to represent a cemented fixed metal‒ceramic partial denture. Three models were set to reduce the number of abutment teeth: 1) lateral incisor, canine, and first premolar; 2) canine and first premolar; 3) the first premolar. The second premolar and first molar were set as pontics, and the second molar was set as an implant abutment in all the models. Finite element analyses were performed under physiologic masticatory forces with axial and oblique loading vectors. Results. After simulation of axial loads, the stress peaks on the bone around the implant, the bone around the first premolar, and prosthetic structures did not exhibit significant changes when the number of abutment teeth decreased. However, under oblique loads, decreasing the number of abutment teeth increased stress peaks on the surrounding bone and denture. Conclusion. Increasing the number of dental abutments in tooth‒implant-supported cemented FPD models decreased stresses on its constituents, favoring the prosthetic biomechanics.
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Affiliation(s)
| | - Mariane Beatriz Sordi
- Postgraduate in Dentistry, Federal University of Santa Catarina, Florianópolis, Brazil
| | | | | | | | | | - Artêmio Luiz Zanetti
- Department of Prosthodontics, Faculty of Dentistry, University of São Paulo, São Paulo, Brazil
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Nicolas-Silvente AI, Velasco-Ortega E, Ortiz-Garcia I, Jimenez-Guerra A, Monsalve-Guil L, Ayuso-Montero R, Gil J, Lopez-Lopez J. Influence of Connection Type and Platform Diameter on Titanium Dental Implants Fatigue: Non-Axial Loading Cyclic Test Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17238988. [PMID: 33276652 PMCID: PMC7730231 DOI: 10.3390/ijerph17238988] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 11/29/2020] [Accepted: 11/30/2020] [Indexed: 12/03/2022]
Abstract
Two-pieces dental implants must provide stability of the implant-abutment-interface. The connection type and platform diameter could influence the biomechanical resistance and stress distribution. This study aims to evaluate the fatigue for different types of connections, external and internal, and different platform diameters. Three implant designs with the same length were used: (a) external hexagon/narrow platform; (b) internal double hexagon/narrow platform; (c) internal octagon/regular platform. A fatigue test was developed to establish the number of cycles needed before fracture. A 30º oblique load with a sinusoidal function of fatigue at a frequency of 15 Hz and 10% stress variation was applied to each system. The fatigue load limit (FLL) for design (a) was 190 N, being the nominal-curvature-moment (NCM) = 1.045; FLL = 150 N, with a NCM = 0.825 for (b), and FLL = 325 N, with a NCM = 1.788 for (c). The platform diameter affects the FLL, obtaining lower FLL on a narrow platform. The connection type interferes with the implant walls’ width, especially in narrow implants, making internal connections more unstable at this level. Long-term clinical studies to assess the restoration’s success rate and survival are mandatory.
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Affiliation(s)
- Ana I. Nicolas-Silvente
- Periodontal and Implant Surgery, CEIR Campus Mare Nostrum, School of Dentistry, University of Murcia, 30008 Murcia, Spain;
| | - Eugenio Velasco-Ortega
- Comprehensive Dentistry for Adults and Gerodontology, Faculty of Dentistry, University of Seville, 41009 Seville, Spain; (I.O.-G.); (A.J.-G.); (L.M.-G.)
- Correspondence:
| | - Ivan Ortiz-Garcia
- Comprehensive Dentistry for Adults and Gerodontology, Faculty of Dentistry, University of Seville, 41009 Seville, Spain; (I.O.-G.); (A.J.-G.); (L.M.-G.)
| | - Alvaro Jimenez-Guerra
- Comprehensive Dentistry for Adults and Gerodontology, Faculty of Dentistry, University of Seville, 41009 Seville, Spain; (I.O.-G.); (A.J.-G.); (L.M.-G.)
| | - Loreto Monsalve-Guil
- Comprehensive Dentistry for Adults and Gerodontology, Faculty of Dentistry, University of Seville, 41009 Seville, Spain; (I.O.-G.); (A.J.-G.); (L.M.-G.)
| | | | - Javier Gil
- Chairman of Bioengineering Institute of Technology, Universitat Internacional de Catalunya, 08017 Barcelona, Spain;
| | - Jose Lopez-Lopez
- Faculty of Dentistry, Service of the Medical-Surgical Area of Dentistry Hospital, University of Barcelona, 08007 Barcelona, Spain;
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Yeğin E, Atala MH. Comparison of CAD/CAM manufactured implant-supported crowns with different analyses. Int J Implant Dent 2020; 6:69. [PMID: 33106916 PMCID: PMC7588579 DOI: 10.1186/s40729-020-00267-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 09/17/2020] [Indexed: 11/23/2022] Open
Abstract
Background Present study compared the failure load of CAD/CAM-manufactured implant-supported crowns and the stress distribution on the prosthesis-implant-bone complex with different restoration techniques. Methods The materials were divided into four groups: group L-M: lithium disilicate ceramic (LDS, monolithic), group L-V: LDS ceramic (veneering), group ZL-M: zirconia-reinforced lithium silicate ceramic (ZLS, monolithic), group ZL-V: ZLS ceramic (veneering). Crown restorations were subjected to load-to-failure test (0.5 mm/min). Failure loads of each group were statistically analyzed (two-way ANOVA, post hoc Tukey HSD, α = 0.05). Finite element analysis (FEA) was used to compare the stress distribution of crown restorations. Results Group L-M had the highest failure load (2891.88 ± 410.12 N) with a significant difference from other groups (p < 0.05). Although there was a significant difference between group ZL-M (1750.28 ± 314.96 N) and ZL-V (2202.55 ± 503.14 N), there was no significant difference from group L-V in both groups (2077.37 ± 356.59 N) (p > 0.05). Conclusions The veneer application had opposite effects on ceramics, increased the failure load of ZLS and reduced it for LDS without a statistically significant difference. Both materials are suitable for implant-supported crowns. Different restorative materials did not influence the stress distribution, but monolithic restorations reduced the stress concentration on the implant and bone.
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Affiliation(s)
- Elif Yeğin
- Department of Prosthodontics, Faculty of Dentistry, Biruni University, Istanbul, Turkey.
| | - Mustafa Hayati Atala
- Department of Prosthodontics, Faculty of Dentistry, Medeniyet University, Istanbul, Turkey
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Chidambaravalli K, Krishnan V. Three-Dimensional Finite Element Analysis of Osseointegrated Implants Placed in Bone of Different Densities With Cemented Fixed Prosthetic Restoration. J ORAL IMPLANTOL 2020; 46:480-490. [DOI: 10.1563/aaid-joi-d-19-00144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A key factor for a successful dental implant is the manner in which stresses are transferred to the surrounding bone. Strength of bone is directly related to its density. Maximum stresses are reported to be incurred by the crestal cortical bone surrounding the implant. Displacement of implants is significantly higher in soft cancellous bone than dense bone. Implants are often placed in bone of different densities to support fixed dental prostheses. This study was aimed at assessing stress and deformation generated by osseointegrated implants placed in bone of different densities on a cemented fixed prosthesis when subjected to static and dynamic loading.
A 3-dimensional finite element analysis was done on a computer-aided design model simulating maxillary bone segment with 2 different bone densities (D2 and D4). The effect of loading was evaluated at the implant–bone interface, implant–abutment interface, abutment, implant abutment connecting screw, cementing medium, and fixed prosthesis. Stresses were calculated using von Mises criteria calibrated in megapascals and deformation in millimeters. These were represented in color-coded maps from blue to red (showing minimum to maximum stress/deformation), depicted as contour lines with different colors connecting stress/deformation points. The study found greater von Mises stress in D2 than D4 bone, and in D2 bone the component with higher stress was the implant. Deformation was greater in D4 than D2 bone, and in D4 bone the abutment-prosthesis interface showed more deformation.
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Affiliation(s)
- Kasthuri Chidambaravalli
- Department of Prosthodontics and Crown and Bridge, Amrita School of Dentistry, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| | - Vinod Krishnan
- Department of Prosthodontics and Crown and Bridge, Amrita School of Dentistry, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
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Finite Element Analysis of a New Dental Implant Design Optimized for the Desirable Stress Distribution in the Surrounding Bone Region. PROSTHESIS 2020. [DOI: 10.3390/prosthesis2030019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Dental implant macro- and micro-shape should be designed to maximize the delivery of optimal favorable stresses in the surrounding bone region. The present study aimed to evaluate the stress distribution in cortical and cancellous bone surrounding two models of dental implants with the same diameter and length (4.0 × 11 mm) and different implant/neck design and thread patterns. Sample A was a standard cylindric implant with cylindric neck and V-shaped threads, and sample B was a new conical implant with reverse conical neck and with “nest shape” thread design, optimized for the favorable stress distribution in the peri-implant marginal bone region. Materials and methods: The three-dimensional model was composed of trabecular and cortical bone corresponding to the first premolar mandibular region. The response to static forces on the samples A and B were compared by finite element analysis (FEA) using an axial load of 100 N and an oblique load of 223.6 N (resulting from a vertical load of 100 N and a horizontal load of 200 N). Results: Both samples provided acceptable results under loadings, but the model B implant design showed lower strain values than the model A implant design, especially in cortical bone surrounding the neck region of the implant. Conclusions: Within the limitation of the present study, analyses suggest that the new dental implant design may minimize the transfer of stress to the peri-implant cortical bone.
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Denes BJ, Ait-Lounis A, Wehrle-Haller B, Kiliaridis S. Core Matrisome Protein Signature During Periodontal Ligament Maturation From Pre-occlusal Eruption to Occlusal Function. Front Physiol 2020; 11:174. [PMID: 32194440 PMCID: PMC7066325 DOI: 10.3389/fphys.2020.00174] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 02/13/2020] [Indexed: 12/14/2022] Open
Abstract
The pre-occlusal eruption brings the molars into functional occlusion and initiates tensional strains during mastication. We hypothesized that upon establishment of occlusal contact, the periodontal ligament (PDL) undergoes cell and extracellular matrix maturation to adapt to this mechanical function. The PDL of 12 Wistar male rats were laser microdissected to observe the proteomic changes between stages of pre-occlusal eruption, initial occlusal contact and 1-week after occlusion. The proteome was screened by mass spectrometry and confirmed by immunofluorescence. The PDL underwent maturation upon establishment of occlusion. Downregulation of alpha-fetoprotein stem cell marker and protein synthesis markers indicate cell differentiation. Upregulated proteins were components of the extracellular matrix (ECM) and were characterized with the matrisome project database. In particular, periostin, a major protein of the PDL, was induced following occlusal contact and localized around collagen α-1 (III) bundles. This co-localization coincided with organization of collagen fibers in direction of the occlusal forces. Establishment of occlusion coincides with cellular differentiation and the maturation of the PDL. Co-localization of periostin and collagen with subsequent fiber organization may help counteract tensional forces and reinforce the ECM structure. This may be a key mechanism of the PDL to adapt to occlusal forces and maintain structural integrity.
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Affiliation(s)
- Balazs Jozsef Denes
- Department of Orthodontics, Clinique Universitaire de Médecine Dentaire, University of Geneva, Geneva, Switzerland
| | - Aouatef Ait-Lounis
- Department of Orthodontics, Clinique Universitaire de Médecine Dentaire, University of Geneva, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Bernhard Wehrle-Haller
- Department of Cell Physiology and Metabolism, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Stavros Kiliaridis
- Department of Orthodontics, Clinique Universitaire de Médecine Dentaire, University of Geneva, Geneva, Switzerland
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Saini H, Ackland DC, Gong L, Cheng, Röhrle O. Occlusal load modelling significantly impacts the predicted tooth stress response during biting: a simulation study. Comput Methods Biomech Biomed Engin 2020; 23:261-270. [PMID: 31965827 DOI: 10.1080/10255842.2020.1711886] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Computational models of the masticatory system can provide estimates of occlusal loading during (static) biting or (dynamic) chewing and therefore can be used to evaluate and optimize functional performance of prosthodontic devices and guide dental surgery planning. The modelling assumptions, however, need to be chosen carefully in order to obtain meaningful predictions. The objectives of this study were two-fold: (i) develop a computational model to calculate the stress response of the first molar during biting of a rubber sample and (ii) evaluate the influence of different occlusal load models on the stress response of dental structures. A three-dimensional finite element model was developed comprising the mandible, first molar, associated dental structures, and the articular fossa and discs. Simulations of a maximum force bite on a rubber sample were performed by applying muscle forces as boundary conditions on the mandible and computing the contact between the rubber and molars (GS case). The molar occlusal force was then modelled as a single point force (CF1 case), four point forces (CF2 case), and as a sphere compressing against the occlusal surface (SL case). The peak enamel stress for the GS case was 110 MPa and 677 MPa, 270 MPa and 305 MPa for the CF1, CF2 and SL cases, respectively. Peak dentin stress for the GS case was 44 MPa and 46 MPa, 50 MPa and 63 MPa for the CF1, CF2 and SL cases, respectively. Furthermore, the enamel stress distribution was also strongly correlated to the occlusal load model. The way in which occlusal load is modelled has a substantial influence on the stress response of enamel during biting, but has relatively little impact on the behavior of dentin. The use of point forces or sphere contact to model occlusal loading during mastication overestimates enamel stress magnitude and also influences enamel stress distribution.
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Affiliation(s)
- Harnoor Saini
- Institute for Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Stuttgart, Germany
| | - David C Ackland
- Department of Biomedical Engineering, University of Melbourne, Victoria, Australia
| | - Lulu Gong
- School of Life Sciences and Technology, Tongji University, Shanghai, P.R. China
| | - Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Riddet Institute, Palmerston North, New Zealand
| | - Oliver Röhrle
- Institute for Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Stuttgart, Germany.,Stuttgart Center of Simulation Science (SC SimTech), University of Stuttgart, Stuttgart, Germany.,Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA, Stuttgart, Germany
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Robinson D, Aguilar L, Gatti A, Abduo J, Lee PVS, Ackland D. Load response of the natural tooth and dental implant: A comparative biomechanics study. J Adv Prosthodont 2019; 11:169-178. [PMID: 31297176 PMCID: PMC6609758 DOI: 10.4047/jap.2019.11.3.169] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 05/11/2019] [Accepted: 06/11/2019] [Indexed: 11/23/2022] Open
Abstract
PURPOSE While dental implants have displayed high success rates, poor mechanical fixation is a common complication, and their biomechanical response to occlusal loading remains poorly understood. This study aimed to develop and validate a computational model of a natural first premolar and a dental implant with matching crown morphology, and quantify their mechanical response to loading at the occlusal surface. MATERIALS AND METHODS A finite-element model of the stomatognathic system comprising the mandible, first premolar and periodontal ligament (PDL) was developed based on a natural human tooth, and a model of a dental implant of identical occlusal geometry was also created. Occlusal loading was simulated using point forces applied at seven landmarks on each crown. Model predictions were validated using strain gauge measurements acquired during loading of matched physical models of the tooth and implant assemblies. RESULTS For the natural tooth, the maximum vonMises stress (6.4 MPa) and maximal principal strains at the mandible (1.8 mε, −1.7 mε) were lower than those observed at the prosthetic tooth (12.5 MPa, 3.2 mε, and −4.4 mε, respectively). As occlusal load was applied more bucally relative to the tooth central axis, stress and strain magnitudes increased. CONCLUSION Occlusal loading of the natural tooth results in lower stress-strain magnitudes in the underlying alveolar bone than those associated with a dental implant of matched occlusal anatomy. The PDL may function to mitigate axial and bending stress intensities resulting from off-centered occlusal loads. The findings may be useful in dental implant design, restoration material selection, and surgical planning.
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Affiliation(s)
- Dale Robinson
- Department of Biomedical Engineering, University of Melbourne, Victoria, Australia
| | - Luis Aguilar
- Department of Biomedical Engineering, University of Melbourne, Victoria, Australia
| | - Andrea Gatti
- Department of Biomedical Engineering, University of Melbourne, Victoria, Australia
| | - Jaafar Abduo
- Melbourne Dental Shool, University of Melbourne, Victoria, Australia
| | - Peter Vee Sin Lee
- Department of Biomedical Engineering, University of Melbourne, Victoria, Australia
| | - David Ackland
- Department of Biomedical Engineering, University of Melbourne, Victoria, Australia
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Sánchez Lasheras F, Gracia Rodríguez J, Mauvezín-Quevedo M, Martín-Fernández E, Bobes-Bascarán J, de Llanos-Lanchares H, Álvarez-Arenal Á. Does the transversal screw design increase the risk of mechanical complications in dental implants? A finite elements analysis. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3205. [PMID: 30916467 DOI: 10.1002/cnm.3205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/18/2019] [Accepted: 03/21/2019] [Indexed: 06/09/2023]
Abstract
The transversal screw was introduced in order to overcome some disadvantages of the transocclusal screw. However, its mechanical risk has not been studied sufficiently. The main purpose of this research was to assess and compare stress distribution in the screws and abutment of a single-crown implant with transversal and transocclusal screw models. Two 3D models were assembled to analyse a single-implant-supported prosthesis with transversal and transocclusal screws embedded in the jawbone. The crown was subjected to a static load of value 300 N with different levels of inclination. The transversal screw model, with an axial load of 15°, was the one with lowest stress values in all its components. However, the stress was greater with more inclined loads when compared with the transocclusal model. The prosthetic transversal screw showed much less stress than the rest of the components for any load inclination. The transversal screw design is the option with the lowest risk of mechanical complications, both in the prosthetic screw and in the abutment screw, when applying forces of lower inclination. The more oblique forces favoured a better biomechanical environment in the abutment and its screw in the transocclusal screw model.
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A 3D finite element analysis of glass fiber reinforcement designs on the stress of an implant-supported overdenture. J Prosthet Dent 2019; 121:865.e1-865.e7. [DOI: 10.1016/j.prosdent.2019.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 11/24/2022]
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Chatterjee S, Sarkar S, Kalidindi SR, Basu B. Periprosthetic biomechanical response towards dental implants, with functional gradation, for single/multiple dental loss. J Mech Behav Biomed Mater 2019; 94:249-258. [PMID: 30928669 DOI: 10.1016/j.jmbbm.2019.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 02/28/2019] [Accepted: 03/02/2019] [Indexed: 01/23/2023]
Abstract
The differences in shape and stiffness of the dental implants with respect to the natural teeth (especially, dental roots) cause a significant alteration of the periprosthetic biomechanical response, which typically leads to bone resorption and ultimately implant loosening. In order to avoid such clinical complications, the implant stiffness needs to be appropriately adapted. In this study, hollow channels were virtually introduced within the designed implant screws for reduction of the overall stiffness of the prototype. In particular, two opposing radial gradients of increasing hollow channel diameters, i.e., outside to inside (Channel 1) and inside to outside (Channel 2) were considered. Two clinical situations of edentulism were addressed in this finite element-based study, and these include a) loss of the first molar, and b) loss of all the three molars. Consequently, two implantation approaches were simulated for multiple teeth loss - individual implantation and implant supported dental bridge. The effects of implant length, approach and channel distribution on the biomechanical response were evaluated in terms of the von Mises stress within the interfacial periprosthetic bone, under normal masticatory loading. The results of our FE analysis clearly reveal significant variation in periprosthetic bone stress between the different implant designs and approaches. An implant screw length of 11 mm with the Channel 2 configuration was found to provide the best biomechanical response. This study also revealed that the implant supported dental bridge approach, which requires lower bone invasion, results in favorable biomechanical response in case of consecutive multiple dental loss.
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Affiliation(s)
- Subhomoy Chatterjee
- Materials Research Centre, Indian Institute of Science, Bengaluru 560012, Karnataka, India; Translational Center on Biomaterials for Orthopaedic and Dental Applications, Indian Institute of Science, Bengaluru 560012, Karnataka, India.
| | - Sulagna Sarkar
- Materials Research Centre, Indian Institute of Science, Bengaluru 560012, Karnataka, India; Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700032, West Bengal, India.
| | - Surya R Kalidindi
- Materials Research Centre, Indian Institute of Science, Bengaluru 560012, Karnataka, India; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332, USA.
| | - Bikramjit Basu
- Materials Research Centre, Indian Institute of Science, Bengaluru 560012, Karnataka, India; Translational Center on Biomaterials for Orthopaedic and Dental Applications, Indian Institute of Science, Bengaluru 560012, Karnataka, India; Centre for BioSystems and Engineering, Indian Institute of Science, Bengaluru 560012, Karnataka, India.
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Brune A, Stiesch M, Eisenburger M, Greuling A. The effect of different occlusal contact situations on peri-implant bone stress - A contact finite element analysis of indirect axial loading. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 99:367-373. [PMID: 30889710 DOI: 10.1016/j.msec.2019.01.104] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 01/21/2019] [Accepted: 01/23/2019] [Indexed: 11/17/2022]
Abstract
Implant restoration is one of the basic treatments in dentistry today, yet implant loss from occlusal overload is still a problem. Complex biomechanical problems such as occlusal overload are often analyzed by means of the finite element method. This numerical method makes it possible to analyze in detail the influence that different loading situations have upon implants and tissues, which is a key element in optimizing these dental procedures. This study was designed to investigate the stress distribution in peri-implant bone of a single-tooth implant crown using the finite element method. The load was applied indirectly via an occluding tooth through a three and five contact setup into the implant crown. The friction coefficient values between the crown and antagonist were varied between 0.1 and 1.0. Additionally, three crowns with cusp inclinations of 20°, 30° and 40° were modeled. Non-linear contact computations indicated that an increase in friction changed the direction and magnitude of contact forces, which also led to reduced stresses in the bone. Furthermore, the stress magnitudes were higher when cusps of a greater inclination were used. The intensity of stress alterations was strongly dependent on the distribution and number of contacts, and the contact force vector. In maximum intercuspation, a resulting axial load due to well-distributed contacts prevented high stresses in bone even with high cusp inclinations and low friction. Therefore for long-term clinical success, particular attention should be paid to occlusal adjustment so as to prevent oblique loading onto dental implant restorations.
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Affiliation(s)
- Annike Brune
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
| | - Meike Stiesch
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
| | - Michael Eisenburger
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
| | - Andreas Greuling
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
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Mendoza-Azpur G, Jaime FS, Angeles R, Danesh-Sani SA, Mendoza-Delgadillo G, Khouly I. Biomechanical Effect of Masticatory Forces in Tenting Screws Used for Vertical Ridge Augmentation. J ORAL IMPLANTOL 2018; 45:165-170. [PMID: 30280962 DOI: 10.1563/aaid-joi-d-18-00139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Gerardo Mendoza-Azpur
- 1 Department of Periodontology, School of Dentistry, Cientifica del Sur University Lima, Peru
| | - Fernando Songhurst Jaime
- 2 Department of Implant Dentistry, School of Dentistry, Cientifica del Sur University Lima, Peru
| | - Romy Angeles
- 3 Department of Prostodontic, School of Dentistry, Cientifica del Sur University Lima, Peru
| | - Seyed Amir Danesh-Sani
- 4 Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, NY
| | | | - Ismael Khouly
- 6 Department of Oral and Maxillofacial Surgery, New York University College of Dentistry, New York, NY; Periodontology & Implant Dentistry, Bluestone Center for Clinical Research, New York University College of Dentistry, New York, NY
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Zarei M, Jahangirnezhad M, Yousefimanesh H, Robati M, Robati H. A comparative study on the stress distribution around dental implants in three arch form models for replacing six implants using finite element analysis. J Indian Soc Periodontol 2018; 22:127-132. [PMID: 29769767 PMCID: PMC5939020 DOI: 10.4103/jisp.jisp_141_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background Dental implant is a method to replacement of missing teeth. It is important for replacing the missed anterior teeth. In vitro method is a safe method for evaluation of stress distribution. Finite element analysis as an in vitro method evaluated stress distribution around replacement of six maxillary anterior teeth implants in three models of maxillary arch. Materials and Methods In this in vitro study, using ABAQUS software (Simulia Corporation, Vélizy-Villacoublay, France), implant simulation was performed for reconstruction of six maxillary anterior teeth in three models. Two implants were placed on both sides of the canine tooth region (A model); two implants on both sides of the canine tooth region and another on one side of the central incisor region (B model); and two implants on both sides of the canine tooth region and two implants in the central incisor area (C model). All implants evaluated in three arch forms (tapered, ovoid, and square). Data were analyzed by finite analysis software. Results Von Mises stress by increasing of implant number was reduced. In a comparison of A model in each maxillary arch, the stress created in the cortical and cancellous bones in the square arch was less than ovoid and tapered arches. The stress created in implants and cortical and cancellous bones in C model was less than A and B models. Conclusions The C model (four-implant) reduced the stress distribution in cortical and cancellous bones, but this pattern must be evaluated according to arch form and cost benefit of patients.
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Affiliation(s)
- Maryam Zarei
- Department of Periodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mahmoud Jahangirnezhad
- Department of Periodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Hojatollah Yousefimanesh
- Department of Periodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Maryam Robati
- Department of Oral Medicine, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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DOGRU SUZANCANSEL, CANSIZ EROL, ARSLAN YUNUSZIYA. A REVIEW OF FINITE ELEMENT APPLICATIONS IN ORAL AND MAXILLOFACIAL BIOMECHANICS. J MECH MED BIOL 2018. [DOI: 10.1142/s0219519418300028] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Finite element method (FEM) is preferred to carry out mechanical analyses for many complex biomechanical structures. For most of the biomechanical models such as oral and maxillofacial structures or patient-specific dental instruments, including nonlinearities, complicated geometries, complex material properties, or loading/boundary conditions, it is not possible to accomplish an analytical solution. The FEM is the most widely used numerical approach for such cases and found a wide range of application fields for investigating the biomechanical characteristics of oral and maxillofacial structures that are exposed to external forces or torques. The numerical results such as stress or strain distributions obtained from finite element analysis (FEA) enable dental researchers to evaluate the bone tissues subjected to the implant or prosthesis fixation from the viewpoint of (i) mechanical strength, (ii) material properties, (iii) geometry and dimensions, (iv) structural properties, (v) loading or boundary conditions, and (vi) quantity of implants or prostheses. This review paper evaluates the process of the FEA of the oral and maxillofacial structures step by step as followings: (i) a general perspective on the techniques for creating oral and maxillofacial models, (ii) definitions of material properties assigned to oral and maxillofacial tissues and related dental materials, (iii) definitions of contact types between tissue and dental instruments, (iv) details on loading and boundary conditions, and (v) meshing process.
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Affiliation(s)
- SUZAN CANSEL DOGRU
- Department of Mechanical Engineering, Faculty of Engineering, Istanbul University, Avcilar, Istanbul 34320, Turkey
| | - EROL CANSIZ
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Istanbul University, Capa, Istanbul 34093, Turkey
| | - YUNUS ZIYA ARSLAN
- Department of Mechanical Engineering, Faculty of Engineering, Istanbul University, Avcilar, Istanbul 34320, Turkey
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Cinel S, Celik E, Sagirkaya E, Sahin O. Experimental evaluation of stress distribution with narrow diameter implants: A finite element analysis. J Prosthet Dent 2018. [DOI: 10.1016/j.prosdent.2017.04.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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de Carvalho EB, Herbst PE, Faria ACL, Ribeiro RF, Costa PP, Tiossi R. Strain transfer behavior of different planning options for mandibular single-molar replacement. J Prosthet Dent 2018; 119:250-256. [DOI: 10.1016/j.prosdent.2017.03.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/25/2017] [Accepted: 03/27/2017] [Indexed: 10/19/2022]
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Kanneganti KC, Vinnakota DN, Pottem SR, Pulagam M. Comparative effect of implant-abutment connections, abutment angulations, and screw lengths on preloaded abutment screw using three-dimensional finite element analysis: An in vitro study. J Indian Prosthodont Soc 2018; 18:161-167. [PMID: 29692570 PMCID: PMC5903180 DOI: 10.4103/jips.jips_219_17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 02/26/2018] [Indexed: 11/25/2022] Open
Abstract
Purpose: The purpose of this study is to compare the effect of implant-abutment connections, abutment angulations, and screw lengths on screw loosening (SL) of preloaded abutment using three dimensional (3D) finite element analysis. Materials and Methods: 3D models of implants (conical connection with hex/trilobed connections), abutments (straight/angulated), abutment screws (short/long), and crown and bone were designed using software Parametric Technology Corporation Creo and assembled to form 8 simulations. After discretization, the contact stresses developed for 150 N vertical and 100 N oblique load applications were analyzed, using ABAQUS. By assessing damage initiation and shortest fatigue load on screw threads, the SL for 2.5, 5, and 10 lakh cyclic loads were estimated, using fe-safe program. The obtained values were compared for influence of connection design, abutment angulation, and screw length. Results: In straight abutment models, conical connection showed more damage (14.3%–72.3%) when compared to trilobe (10.1%–65.73%) at 2.5, 5, and 10 lakh cycles for both vertical and oblique loads, whereas in angulated abutments, trilobe (16.1%–76.9%) demonstrated more damage compared to conical (13.5%–70%). Irrespective of the connection type and abutment angulation, short screws showed more percentage of damage compared to long screws. Conclusions: The present study suggests selecting appropriate implant-abutment connection based on the abutment angulation, as well as preferring long screws with more number of threads for effective preload retention by the screws.
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Affiliation(s)
| | - Dileep Nag Vinnakota
- Department of Prosthodontics, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India
| | - Srinivas Rao Pottem
- Department of Prosthodontics, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India
| | - Mahesh Pulagam
- Department of Prosthodontics, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India
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Singh I, Nair KC, Shetty J. Effect of joining the sectioned implant-supported prosthesis on the peri-implant strain generated in simulated mandibular model. J Indian Prosthodont Soc 2017; 17:388-394. [PMID: 29249883 PMCID: PMC5730916 DOI: 10.4103/jips.jips_144_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 09/25/2017] [Indexed: 11/05/2022] Open
Abstract
Aim: The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering. Materials and Methods: A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. University of California, Los Angeles, abutment was attached to the implant fixture. Eight strain gauges were attached to the acrylic resin model. Six similar models were made. Implant-supported screw-retained fixed prosthesis was fabricated in nickel-chromium alloy. A load of 400 N was applied on the prosthesis using universal testing machine. Resultant strain was measured in each strain gauge. All the prostheses were sectioned at the area between 36 and 33, 33 and 43, and 43 and 46 using 35 micrometer carborundum disc, and strain was measured in each strain gauge after applying a load of 400 N on the prosthesis. Specimens were joined by arc welding, soldering, and laser welding. After joining, a load of 400 N was applied on each prosthesis and the resultant strain was measured in each strain gauge. Results: Highest mean strain values were recorded before sectioning of the prostheses (889.9 microstrains). Lowest mean strain values were recorded after sectioning the prosthesis and before reuniting it (225.0 microstrains). Conclusions: Sectioning and reuniting the long-span implant prosthesis was found to be a significant factor in influencing the peri-implant strain.
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Affiliation(s)
- Ipsha Singh
- KLES's Institute of Dental Sciences, Bengaluru, Karnataka, India
| | | | - Jayakar Shetty
- AECS Maaruti Dental College, Bengaluru, Karnataka, India
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Peixoto HE, Camati PR, Faot F, Sotto-Maior BS, Martinez EF, Peruzzo DC. Rehabilitation of the atrophic mandible with short implants in different positions: A finite elements study. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 80:122-128. [PMID: 28866146 DOI: 10.1016/j.msec.2017.03.310] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 03/07/2017] [Accepted: 03/12/2017] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The aim of this study was to analyze whether the use of inclined short implants without lower transcortical involvement (test model - SI), thus preserving the mandibular lower cortical bone, could optimize stress distribution. MATERIALS AND METHODS Six identical atrophic mandible models were created featuring 8mm of height at the symphysis. Two study factors were evaluated: implant length and angulation. Implant length was represented either by short implants (7mm) with preservation of the mandibular lower cortical bone or standard implants (9mm) with a bicortical approach and 3 possible implant positioning configurations: 4 distally-inclined implants at 45° (experimental model), all-on-four, 4 vertical implants. All tridimensional (3D) models were analyzed using the Finite Element Method (FEM) and the Ansys Workbench software. RESULTS The maximum stress on the bone at the cervical region of the implants in the experimental model was 132MPa and transcortical involvement with implant inclination yielded higher values (171MPa). Regarding von Mises stress on the retaining screw of the prosthesis, 61MPa was recorded for the experimental model while upright implants had the highest values (223MPa). At the acrylic base, 4MPa was recorded for the experimental model whereas models with upright implants showed the highest stress values (11MPa). CONCLUSION Rehabilitation of severely resorbed mandibles with 4 short implants placed distally at 45°, without lower transcortical involvement, were biomechanically more favorable, generating lower stress peaks, than the models with short implants on an all-on-four, or on an upright configuration, with or without lower transcortical involvement.
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Affiliation(s)
- Hugo E Peixoto
- São Leopoldo Mandic Dental Institute and Research Center, Campinas, SP, Brazil
| | | | - Fernanda Faot
- Federal University of Pelotas, Department of Restorative Dentistry, Pelotas, RS, Brazil
| | - Bruno S Sotto-Maior
- Federal University of Juiz de Fora, Department of Restorative Dentistry, Juiz de Fora, MG, Brazil; Brazil and São Leopoldo Mandic Dental Institute and Research Center, Campinas, SP, Brazil
| | | | - Daiane C Peruzzo
- São Leopoldo Mandic Dental Institute and Research Center, Campinas, SP, Brazil.
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dos Santos Marsico V, Lehmann RB, de Assis Claro CA, Amaral M, Vitti RP, Neves ACC, da Silva Concilio LR. Three-dimensional finite element analysis of occlusal splint and implant connection on stress distribution in implant–supported fixed dental prosthesis and peri-implantal bone. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 80:141-148. [DOI: 10.1016/j.msec.2017.05.071] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 05/02/2017] [Accepted: 05/13/2017] [Indexed: 10/19/2022]
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Occlusal loading during biting from an experimental and simulation point of view. Dent Mater 2017; 34:58-68. [PMID: 29017762 DOI: 10.1016/j.dental.2017.09.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 09/15/2017] [Indexed: 11/20/2022]
Abstract
OBJECTIVES Occlusal loading during clenching and biting is achieved by the action of the masticatory system, and forms the basis for the evaluation of the functional performance of prosthodontic and maxillofacial components. This review provides an overview of (i) current bite force measurement techniques and their limitations and (ii) the use of computational modelling to predict bite force. A brief simulation study highlighting the challenges of current computational dental models is also presented. METHODS Appropriate studies were used to highlight the development and current bite force measurement methodologies and state-of-the-art simulation for computing bite forces using biomechanical models. RESULTS While a number of strategies have been developed to measure occlusal forces in three-dimensions, the use of strain-gauges, piezo-electric sensors and pressure sheets remain the most widespread. In addition to experimental-based measurement techniques, bite force may be also estimated using computational models of the masticatory system. Simulations of different bite force models clearly show that the use of three-dimensional force measurements enriches the evaluation of masticatory functional performance. SIGNIFICANCE Hence, combining computational modelling with three-dimensional force measurement techniques can significantly improve the evaluation of masticatory system and the functional performance of prosthodontic components.
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Abstract
PURPOSE Occlusal overload may cause implant biomechanical failures, marginal bone loss, or even complete loss of osseointegration. Thus, it is important for clinicians to understand the role of occlusion in implant long-term stability. This systematic review updates the understanding of occlusion on dental implants, the impact on the surrounding peri-implant tissues, and the effects of occlusal overload on implants. Additionally, recommendations of occlusal scheme for implant prostheses and designs were formulated. MATERIALS AND METHODS Two reviewers completed a literature search using the PubMed database and a manual search of relevant journals. Relevant articles from January 1950 to September 20, 2015 published in the English language were considered. RESULTS Recommendations for implant occlusion are lacking in the literature. Despite this, implant occlusion should be carefully addressed. CONCLUSION Recommendations for occlusal schemes for single implants or fixed partial denture supported by implants include a mutually protected occlusion with anterior guidance and evenly distributed contacts with wide freedom in centric relation. Suggestions to reduce occlusal overload include reducing cantilevers, increasing the number of implants, increasing contact points, monitoring for parafunctional habits, narrowing the occlusal table, decreasing cuspal inclines, and using progressive loading in patients with poor bone quality. Protecting the implant and surrounding peri-implant bone requires an understanding of how occlusion plays a role in influencing long-term implant stability.
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ABU HASAN MD, SHIAKOLAS PANOSS. COMPARATIVE STRESS ANALYSIS OF LINGUALIZED AND CONVENTIONAL BALANCED OCCLUSION SCHEMES IN A FULL-ARCH FIXED IMPLANT PROSTHESIS USING FINITE ELEMENT ANALYSIS. J MECH MED BIOL 2017. [DOI: 10.1142/s0219519417500749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study compares the biomechanical behavior of a mandibular full-arch fixed implant prosthesis with four implants under lingualized and conventional balanced occlusion schemes. The acrylic resin denture was supported by four titanium cylindrical implants and connected via a titanium prosthetic rectangular bar. Orthotropic material was used for the cortical and cancellous bones. The applied loadings were vertical and bilateral: 100[Formula: see text]N on first molar and 50[Formula: see text]N on first and second premolars each. For the lingualized balanced occlusion, the loadings were applied in central fossae of the posterior teeth, whereas for the conventional balanced occlusion the loadings were applied in central fossae and buccal cusps. The maximum von-Mises stresses for the lingualized and conventional balanced schemes were 301[Formula: see text]MPa and 25[Formula: see text]MPa, respectively, and were located at the neck of the posterior implants. In the denture teeth, the highest stress was located at the beginning of the cantilever extension. In the cortical bone, according to Tsai–Wu criterion, the failure index for the lingualized balanced occlusion was 1.10 and for the conventional balanced occlusion was 0.83. Thus, the conventional balanced occlusion demonstrated more favorable stress distribution in the implants and the cortical bone than the lingualized balanced occlusion.
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Affiliation(s)
- MD ABU HASAN
- Micro Manufacturing Medical Automation and Robotics Laboratory, Department of Mechanical Engineering, The University of Texas at Arlington, Arlington, TX 76010, USA
| | - PANOS S. SHIAKOLAS
- Micro Manufacturing Medical Automation and Robotics Laboratory, Department of Mechanical Engineering, The University of Texas at Arlington, Arlington, TX 76010, USA
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Fracture Resistance of Internal Conical and External Hexagon: Regular and Narrow Implant-Abutment Assemblies. IMPLANT DENT 2017; 25:510-4. [PMID: 27280738 DOI: 10.1097/id.0000000000000446] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim of this study was to compare the maximum load on the elastic limit of internal conical (IC) implants with regular external hexagon (REH) and narrow external hexagon (NEH) implants. MATERIALS AND METHODS Thirty cylindrical implants were divided in 3 groups (n = 10): REH (3.75 mm); NEH (3.3 mm); IC (3.5 mm). The implants were evaluated by means of cantilever bending loads using a mechanical testing machine. A strain qualitative analysis and the corresponding angles were analyzed. Using single factor analysis of variance with Tukey Test and Friedman Test (P < 0.05) the statistical analysis for data were performed. RESULTS REH (294.37 N) and IC (294.37 N) groups presented statistically greater Fle than NEH (189.16 N). Regarding to the strain, there were no significant differences among groups. However, there were a greater number of fissures and more fractures present on NEH group. CONCLUSION The IC implant with smaller diameter did not result in reduction of elastic limit when compared with the REH implants. Nevertheless, the reduction of 0.45 mm of the hexagonal connection implant's diameter has significantly diminished the elastic limit.
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Comparison Between Cortical Drill and Cortical Tap and Their Influence on Primary Stability of Macro-Thread Tapered Implant in Thin Crestal Cortical Bone and Low-Density Bone. IMPLANT DENT 2017; 26:711-717. [PMID: 28542042 DOI: 10.1097/id.0000000000000614] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the effect of different surgical techniques on primary stability, particularly in poor-quality bone with or without a crestal cortical bone. MATERIALS AND METHODS Three implant site preparation techniques-undersized drilling (UD), undersized drilling and coronal widening with a cortical drill (UD + CD), undersized drilling and coronal tapping with a cortical tap (UD + CT)-were compared in 2 different low-density polyurethane bone models either with or without the crestal cortical bone. Insertion torque values (ITVs) for each technique was recorded. RESULTS Statistically significant difference was observed for all 3 surgical techniques. In the presence of a crestal cortical bone, the peak ITV for UD was the highest, UD + CT the second, and UD + CD the lowest. All peak ITVs remained significantly lower in the absence of a crestal cortical bone. CONCLUSION Our findings suggested that UD + CTmay be the most effective implant surgical technique to achieve an ideal primary stability in low-density bone with a thin crestal cortical bone layer. Also, this technique may prevent compression necrosis of the dense cortical bone.
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Razaghi R, Biglari H, Karimi A. Dynamic finite element simulation of dental prostheses during chewing using muscle equivalent force and trajectory approaches. J Med Eng Technol 2017; 41:314-324. [PMID: 28351224 DOI: 10.1080/03091902.2017.1299231] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The long-term application of dental prostheses inside the bone has a narrow relation to its biomechanical performance. Chewing is the most complicated function of a dental implant as it implements different forces to the implant at various directions. Therefore, a suitable holistic modelling of the jaw bone, implant, food, muscles, and their forces would be deemed significant to figure out the durability as well as functionality of a dental implant while chewing. So far, two approaches have been proposed to employ the muscle forces into the Finite Element (FE) models, i.e. Muscle Equivalent Force (MEF) and trajectory. This study aimed at propounding a new three-dimensional dynamic FE model based on two muscle forces modelling approaches in order to investigate the stresses and deformations in the dental prosthesis as well as maxillary bone during the time of chewing a cornflakes bio. The results revealed that both contact and the maximum von Mises stress in the implant and bones for trajectory approach considerably exceed those of the MEF. The maximum stresses, moreover, are located around the neck of implant which should be both clinically and structurally strong enough to functionally maintain the bone-implant interface. In addition, a higher displacement due to compressive load is observed for the implant head in trajectory approach. The results suggest the benefits provided by trajectory approach since MEF approach would significantly underestimate the stresses and deformations in both the dental prosthesis and bones.
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Affiliation(s)
- Reza Razaghi
- a Mechanical Engineering Department , University of Tabriz , Tabriz , Iran
| | - Hasan Biglari
- a Mechanical Engineering Department , University of Tabriz , Tabriz , Iran
| | - Alireza Karimi
- b Research Department , Basir Eye Health Research Center , Tehran , Iran
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