Effect Of Thickness Of Cancellous Bone And Cortical Bone On Stress Distribution In Vicinity Of An Implant

To investigate the stress distribution surrounding an implant under different thickness of cancellous bond and cortical bone,and to analyze the effects of thickness ratio and total thickness on the reliability of an implant.Method By using the commercial finite element method software Abaqus,a simplified three-dimensional model of a jawbone consisting of a cancellous bone,a cortical bone,an implant,and a ceramic crown was constructed,and then the computation was performed.Under the condition that the system was loaded by lateral and normal stresses,the effects of thickness ratio and total thickness of cancellous bone and cortical bone on the stress distribution surrounding the implant were studied,where the thickness ratios were 3:1,2:1,1:1,1:2,1:3 and the total thickness were 0.5,1.0,2.0,3.0,4.0 mm,respectively.Results The maximum stresses on the cortical bone,the cancellous bone as well as the implant were all found to decrease with the increasing of the total thickness of cortical and cancellous bones,with a higher decreasing rate in the range between 0.5～2.0mm and a lower decreasing rate between 2.0～4.0mm.More importantly,the maximum value of stress in the cortical bone within the neck region of the implant was observed to increase dramatically via reducing the total thickness below 2mm,while it was increased in significantly when the total thickness was above 2.0mm.Conclusion The thickness ratio and the total thickness of cancellous bone and cortical bone have strong effects on the stress distribution surrounding the implant;In dental implantation surgery,the total thickness of cancellous bone and cortical bone should be at least2mm,and therefore 2 mm is an optimal value.