BACKGROUND:Less is reported on the influence of cortical bone thickness on displacement and equivalent stress. OBJECTIVE:To analyze the influence of cortical bone thickness on the maximum displacement and equivalent stress at the implant-bone interface through a three-dimensional finite element method,thereby providing some suggestions for oral implantation. METHODS:In this experiment,we selected the cone-shaped CT image data of a patient who was scheduled for mandibular first molar implant restoration.First,we established a mandibular model in Mimics13 software,and then imported it into Solid works 2022 software.According to the related product information,we drew the cone-shaped implant(4.1 mm×10 mm)and the upper prosthesis model.Cortical bone models were obtained according to different cortical bone thicknesses(2.5,2.0,1.5,1.0 mm)and named D1,D2,D3,and D4,respectively.All the models were imported into ANSYS Workbench 2021 software and cross-combined.Finally,we applied vertical and oblique loads to the four groups of models,and analyzed the stress of the models in each group. RESULTS AND CONCLUSION:The peak equivalent stress is lowest in the cancellous bone and highest in the upper prosthesis,that is,at the abutment-implant junction.The peak stress increases with the decrease of cortical bone thickness.The peak stress of the abutment increases with the decrease of cortical bone thickness,and a similar explanation can also be applied to the other implant restoration components.The peak stress in bone tissue and implants increases with the increase of cortical bone thickness.In models D1,D2,D3,the peak stress in implants is higher than that in bone tissue,but the results are reversed in D4.