Three-dimensional Finite Element Study Of Joint Crown Implant Restoration In Different Occlusal Modes

Objective: to explore and analyze the effects of different occlusal contact modes on the internal stress distribution of restoration,implant,restoration abutment,retention screw,bone tissue,binder and restoration in three kinds of occlusal relationship of maxillary central incisor implant.Methods: The conical beam CT images of a patient with implant restoration of maxillary central incisor were extracted from the database,and the maxillary model was established by Mimics software.After the jaw model was imported into Solidworks software,the combined crown restoration model of maxillary central incisor was constructed.The main results are as follows:(1)the stress distribution of the internal structure and bone tissue of the implant restoration under different loading modes was simulated and analyzed by ANSYS software.(2)input Ti-6Al-4V fatigue curve into ANSYS software to simulate the cycle times of retention screws at each loading point in the implant restoration.(3)in ANSYS software,the numerical simulation program of bone remodeling was designed by using the secondary development platform of the software,and the internal structure and density distribution of the three-dimensional model of alveolar bone in the upper middle incisor were simulated and reconstructed.Results:(1)the peak value of equivalent stress can be reduced when the loading point is near in the normal and edge to edge bite,and the peak value of equivalent stress is the lowest in the deep overbite and distal loading.(2)the loading point of normal and edge to edge bite can prolong the cycle times of implant retention screws,and the cycle times of deep overbite and distal loading is the longest.(3)different bite relationships affect the distribution of bone density around the implant.Conclusion: This study shows that(1)the stress peak can be reduced when the bite contact point is located proximal of the joint crown implant restoration.(2)the bite contact mode suitable for normal occlusion cannot be used for deep overbite,which may affect the service life of the retention screw.(3)different bite relationships can change the bone density around the implant.