Using optimization approach to design dental implant in three types of bone quality - A finite element analysis.

Abstract

Background/purpose: The use of finite element (FE) analysis in implant biomechanics offers many advantages over other approaches in simulating the complexity of clinical situations. The aim of this study was to perform an optimization analysis of dental implants with different thread designs in three types of bone quality.

Materials and methods: The three-dimensional FE model of a mandibular bone block with a screw-shaped dental implant and superstructure was simulated. In the optimization analysis, the design variables included the thread pitch and the thread depth of the implant. The objective was to minimize the displacement of the implant to the target value. Three FE models with different bone qualities (D2: better bone quality; D3: ordinary bone quality; D4: poor bone quality) were created.

Results: The FE results showed that the displacement of the implant and the stress of the cortical bone increased, while the Young's modulus of the cancellous bone decreased. In the D2 bone, changing the thread pitch and thread depth had little effect on cortical stress and implant displacement. However, in D3 and D4 bone, increasing thread depth reduced cortical stress by 40 % and implant displacement by at least 9 %.

Conclusion: Adjusted thread depth for D3 and D4 bone would reduce crestal bone stress and increase implant stability, but only a little alteration on crestal bone stress and implant stability for D2 bone.