Three-dimensional Finite Element Analysis Of The Influence Of Implant Number And Segmental Design On The Stress Distribution Of Implant-supported Fixed Partial Denture Of Maxillary Anterior Teeth

Objective:Three-dimensional finite element method was used to analyze and explore the influence of the number of implants and the segmental design on the stress distribution of implant-supported partial denture which provide a reference for the clinical design of implant restoration in the continuous loss of maxillary anterior teeth.Methods:We can get volunteer image data from an adult volunteer.Through Mimics 17.0,the model of the maxillary bone and prosthesis was established,UG NX10.0 was used to draw Straumann implant and assembled implant with the maxillary bone and prosthesis,Then we obtained five group model,respectively are M1,M2,M3,M4 and M5.It is divided into two groups through different combinations,set the material parameters and the apply the load in ANSYS.Group A:M1,M2,M3 and M4 were loaded 45°,128N on the left maxillary central incisor,lateral incisor and canine incisor,respectively.The stress neographs were calculated to analyze the influence of the number of implants on the stress distribution of the maxillary anterior implant-supported partial denture.Group B:M3 and M5 were loaded 45°,300N(150N for each left and right central incisor)on the incisor edge of maxillary central incisor and 2mm above the incisor edge,respectively.The stress neographs were calculated to analyze the influence of segmental design supported by four implants on the stress distribution of the maxillary anterior implant-supported partial denture.Results:1.Three-dimensional models of maxillary bone,upper prosthesis and implant were established.2.Cortical bone stress in the model was mainly concentrated on the buccal side of the implant neck.The stress distribution of cortical bone around the implant was significantly correlated with the number of implants under the loading of central incisor and lateral incisor.The more of implants,the maximum stress were smaller and the stress were more dispersed.When canine were loaded,the maximum stress of cortical bone did not change significantly with the number of implants.3.No matter what kind of way of loading,the implant the maximal displacement were decreased with increasing the number of implants.When incisor were loaded,The maximum displacement of M1(90.4μm)significantly more than M2(45.7 μm),M3(40.9μm)and M4(39.9 μm);When canine was loaded,the maximum displacement decreased with the increase of the number of implants,but it was not significant.Different loading sites also affect the maximum displacement of the implant.In all models,when the incisor was loaded the maximum displacement of the M1 was maximum,While the maximum displacement of the other models was maximum when the lateral incisor was loaded.4.In the restoration of implant-supported partial denture by four implants,the one-section fixed partial denture can more effectively disperse the bone stress than the two-section fixed partial denture.In the same model,the maximum stress when loading on the incisal ridge edge is significantly greater than that loading on the 2 mm from incisal ridge.Conclusion:1.It is not feasible that the fixed partial denture of maxillary anterior teeth 13-23 only implant two implants on the bilateral canine area,and there is a risk of implant fracture and bone resorption;The stress distribution of the maxillary anterior fixed partial denture supported by 6 implants was the best,followed by 4 implants and 3 implants.2.In the fixed partial denture of maxillary anterior teeth supported by four implants,the one-section fixed partial denture is more beneficial to the distribution of stress compared with two-section fixed partial denture.3.In the fixed partial denture of maxillary anterior teeth,the stress distribution of the implant and its surrounding tissues was significantly different at different loading sites.