ABSTRACT
Objective To discuss the effects of implants of different thread face angles on the primary stability of immediately loaded implant using the 3-dimensional finite element analysis with the models of the immediately loaded implants. Methods Using the commercial code of Pro/E software, Hypermesh software, and ABAQUS software we created 3-dimensional finite element models. The micromotions of the finite element models with different screw face angles (V-shape, buttress, square-shape and inverse buttress) were computed with the ABAQUS software. Results Concerning different thread face angles, the micromotion of buttress implant was the minimum and the micromotion of inverse buttress implant was the maximum with vertically loading; the micromotion of inverse buttress implant was the minimum and the micromotion of buttress implant was the maximum with horizontal loading. Conclusions Different screw-types have great influence on vertical interfacial micromotions but little influence on horizontal interfacial micromotions. There are two angles which are formed by top /bottom edge and the implants. The larger are the angles, the smaller are the vertical interfacial micromotions, but the weaker of the strength. Thus in designing the screw-type implants, we should consider the angles of thread faces and the strength.