Abstract: Objective · To study the effect of Nd: YAG water-cooled laser on the titanium implant surface, and evaluate its safety in the treatment of peri-implantitis. Methods · Two different titanium sheets (mechanically polished and sandblasted and acid etched) were used and randomly divided into three groups: Nd: YAG laser treatment group (power 1.5 W, water 2 gas 3, fiber diameter 400 μm, non-contact mode), Er, Cr: YSGG laser treatment group (power 1.5 W, frequency 20 Hz, mode S, water 10%, gas 15%, optical fiber MZ6, non-contact mode) and blank control group. After laser treatment, the effect of laser irradiation on these surfaces was observed by scanning electron microscope (SEM). The amount of cell adhesion was observed by immunofluorescence, and real-time PCR was used to detect the expression of cell adhesion genes. Results · The SEM results of the laser treatment group showed no change in the surface morphology of the titanium sheet. There was no significant difference in the amount of cell adhesion and gene expression in each group of laser treatment on the surface of the titanium sheet (P>0.05), and laser treatment had no effect on it. Conclusion · Disinfection of implants by Nd: YAG water-cooled laser has no effect on the titanium implant surface and is safe for the treatment of peri-implantitis.

Key words: Nd: YAG water-cooled laser, implant surface, safety