Application of Nd: YAG laser in periodontal treatment

Abstract

A low power Nd: YAG laser. with a flexible fine optical fiber has been developed for dental use. To investigte the possibility of application in periodontal treatment, the following studies were made.
The purpose of the first study was to determine which laser energy setting resulted in the best condition. Periodontally-involved extracted teeth with subgingival calculus were used. The tested energy settings were 1.5W, 2.0W, 2.5W and 3.0W. Results obtained were as follows: The efficiency at 1.5W irradiation was significantly lower than that at 2.0W, 2.5W and 3.0W. There was no significant difference in efficiency among 2.0W, 2.5W and 3.0W irradiation.
The purpose of the second study was to reveal the effect of laser irradiation on inactivation of endotoxin artificially adsorbed by the healthy cementum and whether the inactivation of endotoxin spread or not by laser irradiation. After collagenase treatment, the healthy cementum was soaked in endotoxin solution. Energy settings were 30mJ for 2sec, 30mJ for 4sec, 50mJ for 2sec and 50mJ for 4sec. The results showed that endotoxin was inactivated at the irradiated spot at an energy setting of more than 30mJ for 2sec. Inactivation of endotoxin was also observed surrounding the spot.
The purpose of the third study was to investigate the clinical effectiveness of laser irradiation in the periodontal pocket. 16 pairs of periodontal pockets with a probing depth were more than 5mm were selected for the study. One irradiated by laser and the other served as controll. Energy setting was from 1.75W to 2.25W at 20pps. The results showed that gingival crevicular fluid and probing depth were significantly redused in the experimental group. And pus discharge disappeared significantly in the experimental site.
These results may confirm that laser treatment is effective in the treatment of periodontal disease.