| Co-Investigator(Kenkyū-buntansha) |
SATOH Shizuko Tohoku University, Graduate School of Dentistry, Research Associate, 大学院・歯学研究科, 助手 (60225274)
IIKUBO Masahiro Tohoku University, Graduate School of Dentistry, Research Associate, 大学院・歯学研究科, 助手 (80302157)
SUGAWARA Yumiko Tohoku University, Hospital, Research Associate, 病院・助手 (30235866)
ENDO Yasuo Tohoku University, Graduate School of Dentistry, Associate professor, 大学院・歯学研究科, 助教授 (50005039)
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| Research Abstract |
To establish the new method for diagnosing pulpitis by means of measure pulpal blood flow, we develop a new apparatus for measuring pulpal blood flow. First, we investigate the effect of an increase in laser power on the transmitted laser signals from vital and non-vital teeth, in the hope of achieving a better assessment of human pulp vitality with the transmitted laser-light flowmeter. The experiments were carried out on total of 61 vital teeth with no restoration (19 upper central incisors, 16 upper lateral incisors, 16 upper canines, and 10 first premolars) and 5 non-vital upper central incisors (the root canals of which were filled with gutta-percha) in 15 subjects aged 22-28 years. For use with transmitted laser light, the fibers within the probe of a conventional laser Doppler flowmeter (LDF) apparatus were used, one for transmitting light onto the labial surface, the other for receiving it at the palatal surface of the same tooth, as reported previously. Laser output power was
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set at the original 2 mW and also at 5, 7, and 10 mW. The number of vital teeth displaying a blood flow (BF) signal at each laser power setting was : 1) 12/19 central incisors at 2 mW, 19/19 at 5, 7, and 10m W, 2) 19/19 lateral incisors at 2, 5, 7, and 10 mW, 3) 0/16 canines at 2 mW, but eight, twelve, and fourteen at 5, 7, and 10 mW, 4) 0/10 first premolars at 2, 5, 7, and 10 mW. Thus, an increase in laser power increased BF detection from the thicker teeth (but not from premolars). In addition, clearer BF signals synchronized with heart rate, and greater passive BF changes secondary to blood pressure. (BP) changes were observed at higher laser settings. In non-vital teeth, no signals synchronized with heart rate or BP changes were observed, indicating that no blood flow signal of non-pulpal origin was ever monitored with this ballistic light even when the laser power was increased. These results indicate that high-powered transmitted laser light could be a useful tool both for monitoring pulpal blood flow and for the assessment of tooth-pulp vitality. Less
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