The clinical application and the establishment of restoration technique with Er : YAG laser

为了建立Er: YAG激光在牙科修复中的应用，进行了以下检查。本研究采用Erwin （ERWI HOYA Co.）和MORITA Co.)的Er YAG激光器，在实验试验机上进行了切削试验，测定了激光辐照功率、脉冲、辐照距离和角度的变化，考察了这些因素与切削效率的关系。在大多数实验条件下，激光去除牙齿物质的体积与功率成正比。在150omj功率lOpps下，激光对牙本质的切割效率约为空气涡轮切割装置的1/3，对牙釉质的切割效率约为空气涡轮切割装置的1/2。在与表面的90 ~ 30度范围内，照射角度对切割效率没有变化。激光表面未观察到任何因牙齿物质发热而引起的形态变化和裂纹。接下来，我们开发了一种实验性的凿形接触尖端（ECSC tip），用于铸造金属镶嵌体的空腔制备。具有明确的辐照能量分布特性。研究了实验尖端在镶嵌腔制备中的应用。在龋洞准备中，可以获得平坦的牙本质壁。提出利用实验尖端制备嵌体腔是可行的。在临床病例研究中，我们使用激光对200多名到我校附属医院就诊的患者进行了复合树脂修复体的腔体制备。结果非常好，在大多数情况下，激光在治疗期间和治疗后都没有给患者造成疼痛或不适。综上所述，在提高切割效率和缩短制腔时间成为可能后，有望在普通牙科诊所建立Er: YAG激光无痛治疗。

The following examinations were carried out for the purpose of the establishment of application for use to a restorative dentistry with Er : YAG laser. An Erwin (ERWI HOYA Co. and MORITA Co.) Er YAG laser used in this study The tooth cutting efficiency was determined with experimental test machine for cutting tests Changing the power, pulse, irradiation distance and angle with the laser irradiation, , it measured to examine about relation between these factors and cutting efficiency. The volume of removal of tooth substance with the laser was proportioned for the most experimental conditions with the power. At l5OmJ power lOpps the tooth cutting efficiency with the laser was 1/3 in dentin and about 1/2 in enamel that of air turbine cutting device. No changes generated from the angle of irradiation to cutting efficiency in a range from 90 to 30 degrees to surface. Any morphological change and a crack by the fever of a tooth substance were not observed lased surface. Next, we developed an experimental chisel shaped contact tip (ECSC TIP) for use in cavity preparation for cast metal inlays. It has specified irradiation energy distribution characteristic. The usefulness of the experimental tip in inlay cavity preparation was examined.. It was possible to obtain a flat dentin wall inthe cavity preparation. It is suggested that inlay cavity preparation is possible using the experimental tip. In clinical case study, we used the laser with over 200 patients who visited the hospital affiliated with our university for cavity preparation of the composite resin restorations. The results were excellent, and the laser did not cause a pain or discomfort to the patient during and after the treatment in most of the cases. Aforementioned these results, it expected that painless treatment by Er : YAG laser application will be established in general dental clinics after it becomes possible to improve the cutting efficiency and shorten the time for cavity preparation.