Nd:YAG laser irradiation of the human dental pulp: implications as a predictor of pulp hemodynamics.
OBJECTIVE
The aim of study this was to evaluate in vivo the pulpal blood flow rate, pulpal responsiveness, systemic blood pressure, and pulse rate during Nd:YAG laser irradiation of an isolated tooth.


METHODS
Thirteen volunteers from the Tsurumi Dental University faculty participated in this study after giving their consent to the Nd:YAG laser irradiation test protocol. Gingivobuccal areas adjacent to mandibular canines were used for clinical evaluation. Each area was coated with India ink and treated with a Nd:YAG laser for 30 sec at 120-mJ pulses at 10 pulses/sec. Pulpal blood flow was measured by a laser Doppler flowmeter during Nd:YAG laser irradiation of the tooth. All pulp responses were measured by an electric pulp tester before and after Nd:YAG laser irradiation. In addition, the systemic blood pressure and pulse rate were monitored throughout the laser irradiation procedure.


RESULTS
For all subjects involved in this study, the pulpal blood flow rate increased during laser irradiation. Threshold values of the electric pulp tests increased in six cases and decreased in six cases. One case showed no change. After 1 month, the threshold values for each subject had returned to previously recorded values. Neither systemic blood pressure nor pulse rate was affected during Nd:YAG laser irradiation. Pulpal blood flow was strongly influenced immediately after Nd:YAG laser irradiation, seen as an increase in the flow rate.


CONCLUSIONS
The results of this study suggest that effects of the Nd:YAG laser irradiation are similar to those of low power laser for the improvement of local blood flow.
Yamaguchi
H
H
Department of Periodontics and Endodontics, Tsurumi University, School of Dental Medicine, Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan. GZI05343@nifty.ne.jp
Kobayashi
K
K
Sato
Y
Y
Osada
R
R
Sakuraba
E
E
Nomura
T
T
Arai
T
T
Nakamura
J
J
Cox
C F
CF
D000328:Adult; D001783:Blood Flow Velocity / Q000528:radiation effects*; D001794:Blood Pressure / Q000528:radiation effects*; D003782:Dental Pulp / Q000098:blood supply* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005881:Gingiva / Q000098:blood supply / Q000528:radiation effects; D006801:Humans; D007834:Lasers; D008297:Male; D011674:Pulse