Laser Nitriding Treatment of Titanium Prostheses

Abstract

I investigated nitride Ti plating by yttrium aluminum garnet (YAG) laser irradiation in nitrogen atmosphere. Ti nitriding treatment of dental prosthesis by ion-plating and furnace heating has been used to improve esthetics and the biocompatibility. The disadvantages of these surface treatments is that they have a thin nitrided layer, long plating time and unlimited treatment area. Using X-ray defractometer tests, surface roughness, Vicker's hardness, wear resistance and the three point-bending test, laser nitrided specimens were compared to those obtained by ion-plating and furnace heating. All treatments resulted in the appearance of a gold color to the naked eye. X-ray defractometer tests revealed Ti and TiN peaks for laser nitriding and ion-plating, while furnace heating produced Ti₂N peaks. The surface of laser nitrided Ti specimens was rougher than that of pure Ti processed by sand-blasting. The laser nitriding technique was better than the others in terms of Vicker's hardness and wear resistance. The three point-bending test created cracks in all specimens.