PULSED ND-YAG LASER APPLICATION TO ONE-VISIT TREATMENT OF INFECTED ROOT CANALS IN DOGS - A HISTOPATHOLOGICAL STUDY

Objective: In this study, the effects of pulsed Nd:YAG laser irradiati on during root canal treatment of infected teeth were investigated his topathologically in dogs. Summary Background Data: Effects of Nd:YAG l aser on infected root canal treatment have not been reported in vivo. Methods: One hundred thirty-five teeth with a single root, including i ncisors and premolars, in 15 healthy adult beagle-strain dogs were use d in this study, After inducing infection in the teeth, each root cana l was shaped with at least a # 40 K-file, then the canal was irradiate d using the following parameters: 1 W, 30 pps for 1 and 2 sec; 2W, 30 pps for 1 and 2 sec. Efficacy of debris removal and evaporation on the root canal walls at 2 weeks, and the degree of inflammation of the pe riapical region at 2, 4, and 8 weeks after laser irradiation were exam ined histopathologically by light microscopy, Results: Effective debri s removal was observed in all cases of the laser-treated groups. No ev aporation was observed except at the conditions of 2 W for 2 sec. Infl ammation of periapical region in the laser-treated groups was similar in the control group at 2 weeks, but was significantly less than that in the control group at 8 weeks (p < 0.05), Conclusion: These results suggest that pulsed Nd:YAG laser is useful for one-visit root canal tr eatment of infected teeth in dogs, if appropriate parameters are selec ted, and this is a potential therapy for human apical lesions of teeth .