Fatigue behavior of zirconia with microgrooved surfaces produced using femtosecond laser.

Abstract

Femtosecond laser is a promising surface treatment tool for zirconia implant. In this study, the fatigue behavior of zirconia specimens with microgrooved surfaces formed by femtosecond laser is reported. One hundred sixty CAD/CAM zirconia bars (20mm × 4mm × 1.4mm) were evenly divided into four groups with different surface: as sintered; sandblasted with 110μm Al2O3; femtosecond laser produced microgrooves having 50μm width, 30μm depth, and 100μm pitch; microgrooves having 30μm width, 20μm depth, and 60μm pitch. The femtosecond laser formed micro/nanostructured microgrooves with precise size on zirconia surfaces. XRD analysis indicated that microgrooved surface showed no obvious tetragonal-to-monoclinic phase transformation. The fatigue strength of sandblasted specimens (728MPa) was significantly higher than that of as sintered specimens (570MPa). However, the fatigue strength of specimens with microgrooved surface decreased to about 360-380MPa. The results suggest femtosecond laser is an effective technique to regulate the surface microtopography of zirconia, while further investigations are needed to improve its fatigue behavior.