Effects of femtosecond laser treatment on surface characteristics and flexural strength of zirconia

To evaluate the effects of femtosecond laser treated microgrooved surface on microscopic topography, phase transformation, and three-points flexural strength of zirconia, and to provide reference for surface microstructure optimization of zirconia implant. According to different surface treatment methods, 57 computer aided design/computer aided manufacture (CAD/CAM) zirconia bars (20.0 mm×4.0 mm×1.4 mm) were evenly divided into three groups: sintered group, no treatment after sintering, taken as control; sandblasted group, sandblasted with 110 μm aluminium oxide (Al O ) after sintering; microgrooved group, femtosecond laser fabricated microgrooves with 50 μm width, 30 μm depth, and 100 μm pitch. Surface microscopic topography was observed with scanning electron microscope (SEM) and 3D laser microscope. Further, surface roughness in each group and microgroove size were measured. Crystal phase was analyzed with X-ray diffraction. Specimens were subjected to three- points flexural strength test, and Weibull dist