Histopathological changes in dental pulp irradiated by Er:YAG laser: a preliminary report on laser pulpotomy.
OBJECTIVE
The effects of Er:YAG laser irradiation on the pulp tissue during a pulpotomy procedure were evaluated histopathologically.


BACKGROUND
The effects on pulp tissue during laser pulpotomy using Er:YAG laser irradiation are not clear.


METHODS
Sixty 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 15 sec. Non-irradiated canals served as controls. The effects of laser irradiation on the remaining pulp tissue and periodontal tissues were evaluated at 0 days, 2 days, and 1 week after irradiation under light microscopy.


RESULTS
At 1 week 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 was observed in 9 of 10 cases (90%) in the 68 and 102 mJ/pulse-irradiated groups.


CONCLUSIONS
These results suggest that effects on pulp tissues during a pulpotomy procedure by Er:YAG laser irradiation are minimal, if appropriate parameters are selected, and this is a potential therapy for pulpotomy of human teeth.
Kimura
Yuichi
Y
Department of Endodontics, Showa University School of Dentistry, Tokyo, Japan. yukimura@senzoku.showa-u.ac.jp
Yonaga
Kazuo
K
Yokoyama
Keiko
K
Watanabe
Haruji
H
Wang
Xiaogu
X
Matsumoto
Koukichi
K
D000818:Animals; D003782:Dental Pulp / Q000473:pathology* / Q000528:radiation effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar