A comparative finite element simulation of stress in dental implant–bone interface using isotropic and orthotropic material models in three mastication cycles

Although functionally graded biomaterials (FGBMs) have recently been employed in the dental implants, the role of mechanical complications in the FGBMs, i.e., isotropicity or orthotopicity, has not been well understood. This study, hence, was aimed at investigating the effects of a special type of FGBM implant in stress distribution of bone–implant interface using finite element method. Meanwhile, the effects of simplifications, such as presuming isotropic material model instead of an orthotropic one for a jaw bone, and applying a small deflection effect as a replacement for a large deflection effect in the stress–strain calculation were also examined. The results revealed that the FGBM implants can diminish the maximum stress in the implant–bone interface. In addition, although the amount of maximum strain in the bone and implant were low, considering a small deflection effect instead of a large deflection one showed to have a considerable influence in the stress and the displacement of the implant–bone system. The orthotropic bone also indicated a large amount of stress compared with the isotropic one which implies the importance of material models in simulating the stresses and displacements of the implant–bone system. These results have implications not only for understanding the stresses and displacements in the implant–bone interface, but also for providing a comprehensive information for the biomechanical experts to pay enough attention to the material models being employed in their numerical simulations.