Study for developing new caries removal device with air-abrasive technique.

结果表明，在3kgf/cm~2左右的气压下，用直径约100μm的空气研磨技术可以选择性去除龋牙本质，但去除龋齿组织需要较长的时间。为了提高去龋效率，考察了空气压力和/或颗粒大小的几种条件。虽然在较大气压和/或大颗粒条件下去除龋齿组织的时间较短，但在这种情况下，患者在临床使用时会感到疼痛。通常空气磨损采用干法(颗粒被压缩空气加速)，我们尝试使用湿法(颗粒由压缩空气和水一起加速)。虽然众所周知，干法的去龋效果优于湿法，但在本研究中，湿法的去龋率优于干法。当使用干燥技术时，人们认为干燥的龋齿本质变得坚硬。湿法还有其他优点，即减少散落的颗粒，减少切割面的热量，减轻患者的痛苦。结果表明，桃子粉湿式研磨技术具有较好的临床应用价值。结果表明，桃子粉湿法磨削去龋牙表面树脂粘接强度与常规旋转切割装置无明显差异。从现在开始，临床手术的改进将开始。

It was revealed that air abrasive technique with particle (size about 100μm) which was made of the peach seed shell selectively removed caries dentin under air pressure of about 3kgf/cm^2. (GRANT-IN-AID FOR SCIENTIFIC RESERCH (B)) However, it takes a long time to remove caries tissue completely. To improve the efficacy of caries removal, several conditions of air pressure and/or particle size were examined. Though the removal time of caries tissue became short when larger air pressure was supplied and/or large particle was used, under those conditions patients feel pain in clinical use. Usually air abrasion uses dry technique (particles are accelerated by compressed air), we tried to use wet technique (particles are accelerated by compressed air together with water). Though, it is well known that the cutting effect of dry technique is superior to that of wet technique, in this study it was elucidated that caries removal efficacy of wet technique was superior to that of dry technique. It is considered that dried carious dentin became hard when dry technique was used. The wet technique has additional advantages, namely reducing scattered particles reducing the heat of cutting surface and reducing patients' pain. It was ascertained that wet air abrasion technique with peach seed powder is clinically useful in this study. It was confirmed that there was no significant difference between adhesion strength of resin bonding system to the surface of caries removed tooth using wet air abrasion technique with peach seed powder and that of using the conventional rotary cutting device. From now the improvement of the clinical operation will be started.