Morphological and Mechanical Characterization of Porous Titanium for Dental Implants

Methods: Porous titanium is manufactured using a “3D print and sinter” technique. The final sintering temperature is varied in order to vary microstructure and mechanical properties. Morphological investigations are carried out via optical microscopy for surface imaging and microCT for internal imaging. Vicker's microindentation testing is used to determine the microhardness, compressive strength testing generates the yield strength and young's modulus. Additionally, the permeability of the implant is measured to assess the level of interaction with surrounding tissue.

Results: Porosity is in the region of 30 to 40% with interconnectivity levels ranging from 8 to 30%. Internal pore size distribution is small with an average pore size of approximately 60 microns. External pore size distribution is larger with the size of most pores ranging from 60 to 120 microns. Microhardness testing produced a large range of hardness values from approximately 100HV0.05 to in excess of 500HV0.05.

Conclusion: All sintering temperatures produced acceptable hardness values. Porosity, interconnectivity and average pore size reduced with increasing sintering temperature. Surface pore sizes are spread over a wider range than internal pore sizes and surface pores are generally larger than internal pores.

The Singapore Institute of Manufacturing Technology (SIMTech), as part of the Agency for Science, Technology and Research (A*Star) and the University of Sheffield are acknowledged for their support of the project.