Properties of Titanium Dental Implant Models Made by Laser Processing

Abstract

This article discusses the influence of various process parameters on the characteristics of titanium dental implants made by laser-forming techniques involving both laser sintering and laser melting. The implant models have a porous surface structure to increase bone-osseointegration and a compact core to provide the required mechanical strength. Models in the shapes of rod and cone were built using a continuous wave (CW) laser yielding a threshold compressive force as high as 1000 N after a postsintering treatment in a vacuum furnace at 1200°C for 1.5 h. Using selective laser melting with the pulsed laser, the best parameters were found to be: scan speed of 6 mm/s, laser peak power of 1 kW, and hatching pitch of 0.4 mm yielding a tensile strength of 300 MPa and torsional fatigue strength of 100 MPa. To improve the surface wear resistance of the titanium models, laser gas nitriding using CW Nd:YAG laser was applied. The formed TiN layers had a sponge-like structure with a thickness varying from 30 to 60 μm. The hardness measured at ε20 μm from the surface varied from 1000 to 600 HV by changing the scan speed from 1 to 16 mm/s.