Hoji T
Department of Endodontics, Asahi University School of Dentistry.
Gifu Shika Gakkai Zasshi. 1990 Dec;17(2):534-46.
The use of soft lasers in dental therapy has increased dramatically in recent years. However, there is a dearth of reports in the literature of controlled in vivo and in vitro studies of soft laser effectiveness with respect to dentinal pain. The purpose of this study was to assess the analgesic effects of soft laser treatment by the following five studies: (1) Clinical evaluation of soft laser irradiation of hypersensitive dentin. (2) Morphological study of dentinal surfaces following soft laser irradiation. (3) Study of the effect of soft laser irradiation on dentinal fluid movement. (4) Study of the effect of soft laser irradiation on the jaw opening reflex (JOR) in rats. (5) Study of thermal changes on the internal wall of pulp chamber with soft laser irradiation. After soft laser treatment of 3 min to hypersensitive dentin, patients experiences diminished sensitivity in 46 of 55 teeth (83.6%). In model experiment with extracted human teeth, the energy levels of this laser were too low to produce any morphological changes on the surface of exposed dentin, and dentinal fluid movements induced by air blasts for 15 sec to exposed dentin were not affected by laser irradiation to the dentin for 3 min. Moreover, there was an immediate 0.7 degree C increase in the temperature of the internal wall of the pulp chamber by laser irradiation to the tooth surface. In experimental rats, the digastric EMG induced by 1.3 x T (T: threshold value producing the JOR) was reduced by 3 min soft laser irradiation to teeth or Ho-ku points, but not at 2.0 x T. These results suggest that soft lasers have an analgesic effect, but the latter is affected by the degree of stimuli-elicited pain, and may be due in addition to descending inhibition in the central nervous system.
近年来，软激光在牙科治疗中的应用急剧增加。然而，关于软激光对牙本质疼痛有效性的体内和体外对照研究的文献报道却很少。本研究的目的是通过以下五项研究评估软激光治疗的镇痛效果：（1）对过敏牙本质进行软激光照射的临床评估。（2）软激光照射后牙本质表面的形态学研究。（3）软激光照射对牙本质液流动影响的研究。（4）软激光照射对大鼠张口反射（JOR）影响的研究。（5）软激光照射对牙髓腔内壁热变化的研究。对过敏牙本质进行3分钟的软激光治疗后，55颗牙齿中有46颗（83.6%）患者的牙齿敏感度降低。在拔除的人牙模型实验中，该激光的能量水平过低，无法在暴露的牙本质表面产生任何形态学变化，并且对暴露的牙本质进行15秒吹气诱导的牙本质液流动不受对牙本质进行3分钟激光照射的影响。此外，对牙齿表面进行激光照射会使牙髓腔内壁温度立即升高0.7摄氏度。在实验大鼠中，对牙齿或合谷穴进行3分钟的软激光照射可使由1.3×T（T：产生JOR的阈值）诱发的二腹肌肌电图降低，但在2.0×T时则不会。这些结果表明，软激光具有镇痛作用，但后者受刺激引发疼痛程度的影响，并且可能还归因于中枢神经系统的下行抑制。
