NUMERICAL COMPARISON OF TRANSGINGIVAL AND SUBGINGIVAL DENTAL IMPLANTS IN REGARD TO THEIR STRESS DISTRIBUTIONS

Abstract

Most modern dental implants differentiate in regard to the fixation of the abutment into two main categories - the external or internal hexagon or octagon. We performed mechanical tests according to the ČSN EN ISO 14801 standard on a dental implant variant using the external hex. We found that failure of all implant specimens occured below the screw head. To improve the current geometry, we performed numerical analysis of an alternative variant (internal hex) and compared it with analysis of the current geometry (external hex). It was found that the stress distribution of the variant with internal hex is preferable to the old variant. Although extreme values of shear stress in the corresponding plane of loading are higher, they do not concentrate below the screw head, where the screw itself is thinner and more prone to breaking. Therefore, it seems that the new variant of the dental implant is stronger, which is still to be proven by mechanical tests.

Keywords

• external hexagon
• fem
• implant-abutment interface
• internal hexagon
• stress.