MULTI-SCALE FINITE ELEMENT ANALYSIS ON BIOMECHANICAL RESPONSE OF FUNCTIONALLY GRADED DENTAL IMPLANT

This paper proposes a multi-scale finite element method to investigate the biomechanical response of functionally graded dental implant / mandible system. Macroscopically, the proposed dental implant / mandible model consists of a functionally graded biomaterial (FGB) dental implant, a mandible and a dental implant / mandible interface. The mandible was considered to construct with cancellous bone and cortical bone with a graded change in mechanical property between these two bones. The FGB dental implant was modeled to be composed of titanium (Ti) and hydroxyapatite (HA) also with a gradient change in composition between both ends of the implant. The interface was assumed to be at an unhealed state during the initial stage of implantation and later grow to have properties equal to those of healthy cancellous bone after healing. A finite element software package ABAQUS incorporated with a user-defined material subroutine, was used to perform the analysis. Microscopically, the microarchitecture of cancellous bone is modeled by using a face-centered-cubic (FCC) finite element (FE) unit cell model. By using this micro-cell FE model, the time-dependent compressive strength of the implant / mandible interface can be predicted. Macroscopically, the proposed method can also be applied to predict the load bearing capability and stress distribution of the implant / mandible interface.