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Effects on periradicular periodontal tissues of root canal irradiation with Er:YAG laser in rats
Yuichi Kimura1, Kazuo Yonaga, Masao Murakoshi
1Department of Endodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515, Japan. yukimura@senzoku.showa-u.ac.jp
Objective:
The effects of Er:YAG laser irradiation on the periodontal region during root canal preparation were evaluated using rats histopathologically.
Background Data:
The effects on periodontal tissues along the root surface and apical area during root canal preparation using Er:YAG laser irradiation in vivo are not clear.
Methods:
One hundred mesial root canals of mandibular first molars in rats were divided into four groups. In three of these groups, root canals were irradiated using an Er:YAG laser at 2 Hz and 34, 68, and 102 mJ/pulse for 30 sec. Non-irradiated canals served as controls. The effects of laser irradiation on the periodontal tissues along the root surface and apical area were evaluated at 0, 2 days, 1, 2, and 4 weeks after irradiation under light microscopy.
Results:
At 4 weeks after treatment, no inflammation or resorption was observed in any cases in the control or 34 mJ/pulse-irradiated groups. However, moderate to severe inflammation with resorption of root surface was observed in four of five cases (80%) in the 102 mJ/pulse-irradiated group, which was significantly different from the control (p < 0.01).
Conclusions:
These results suggest that the effects on periodontal tissues during root canal preparation by Er:YAG laser irradiation after pulpectomy are minimal, if appropriate parameters are selected, and this is a potential therapy for human root canals of teeth.
