Mechanical performance of titanium alloy dental implants with continuously gradient porous structures

Abstract

In the field of dental prosthodontics, gradient porous structures have significant advantages over non-gradient porous structures in terms of stress shielding mitigation and achieving effective force transmission. This study innovatively constructs four types of continuous gradient porous structures: Diamond, Body Centered Cubic, Face Centered Cubic, and Kelvin Cell. Based on the Gibson Ashby theoretical model, the design parameters corresponding to the desired porosity of each structure were designed. Forty porous structures with continuous gradient variations and eight non-gradient porous structures corresponding to the mean values of two linear gradient porosities were constructed according to different gradient directions and continuous gradient intervals. Using selective laser sintering to fabricate continuous gradient structures and characterize their structural and mechanical properties. The results demonstrate that structures with a broader gradient range exhibit superior mechanical performance. The mechanical properties of Kelvin Cell are better in radial gradient porosity; The mechanical properties of Body-Centered Cubic are better in axial gradient porosity. Compared to the non-gradient structure, both gradient-oriented configurations demonstrate the capability to achieve graded stress distribution. This characteristic facilitates efficient load transfer to the alveolar bone, thereby effectively mitigating stress shielding phenomena. Furthermore, the study revealed that highly symmetric structures perform better in the radial gradient direction, while layered topological structures have greater advantages in the axial gradient direction. The findings of this study provide a theoretical basis for optimizing the mechanical properties of titanium alloy dental implants with continuous gradient porous structures, and also offer technical references for the geometric design of dental implants.