The effect of neodymium:yttrium-aluminum-garnet laser treatment at different power settings and distances on hydroxyapatite-coated dental implants: A scanning electron microscope study

Abstract

Aim: The purpose of this study was to evaluate the surface changes caused by a single pass of pulsed neodymium:yttrium-aluminum-garnet (Nd:YAG) laser on hydroxyapatite (HA)-coated dental implant surfaces, and to report on the effect of varying the distance from the laser fiber tip to the implant surface on laser induced implant surface changes. Materials and methods: Nine HA-coated tapered screw vent implants (Zimmer Dental, Carlsbad, CA) were used in this study. The laser used was the Periolase^TM MVP-7^TM, which is a pulsed Nd:YAG (1062nm) laser. The effect of the laser was evaluated a distance of 3 mm and 10 mm away from implant surfaces at 3 different power settings (0.8 W, 2.0 W, and 3.0 W), which yielded 6 treatment groups: Group 1 (0.8 W at 3mm); Group 2 (0.8 W at 10mm): Group 3 (2.0 W at 3mm); Group 4 (2.0 W at 10mm); Group 5 (3.0 W at 3mm); and Group 6 (3.0 W at 10mm). The implants were examined for the area of surface damage using scanning electron microscopy (SEM). Measurements on SEM images were made at 350x magnification. Data were submitted to an analysis of variance with repeated measures. Results: The mean areas of surface damage were as follows: Group 1 891 μm2 ±129; Group 2 684μm2 ±227; Group 3 2825μm2 ±730; Group 4 2300μm2 ±590; Group 5 5225μm2 ±409; and Group 6 2397μm2 ±370. At 3 mm distance, the mean area of surface damage increased significantly with each higher level of energy. At 10mm distance, the mean area of surface damage increased significantly at 2.0 W and 3.0 W, when compared to 0.8 W; however, no difference was found between 2.0 W and 3.0 W. No obliteration of HA surface was noted. Conclusion: Within the limitations of this study, the surface effects of a single pass of Nd:YAG laser on HA-coated implants appear to be proportional to the laser power output and inversely proportional to the distance from the object being irradiated.