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

为了确定Er：YAG激光在牙科修复中的应用，进行了以下检查。An Erwin（ERWI HOYA Co. and MORITA Co.）本研究采用Er YAG激光器，在切削试验机上进行切削试验，通过改变激光功率、脉冲、照射距离和照射角度，测定切削效率，考察这些因素与切削效率的关系。在大多数实验条件下，用激光去除牙齿物质的体积与功率成比例。在150 mJ功率10 ps下，激光切割牙本质的效率约为空气涡轮机切割装置的1/3，切割牙釉质的效率约为空气涡轮机的1/2。在与表面成90度至30度的范围内，从照射角度到切割效率没有产生变化。激光表面未观察到任何形态学变化和牙体发热引起的裂纹。接下来，我们开发了一种实验性凿形接触尖端（ECSC TIP），用于铸造金属嵌体的腔体制备。它具有特定的辐照能量分布特性。对该实验头在嵌体窝洞制备中的有效性进行了检查。窝洞制备中可获得平整的牙本质壁。这表明，嵌体洞制备是可能的使用实验尖端。在临床病例研究中，我们对200多例来我院进行复合树脂充填体洞型预备的患者进行了激光治疗。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。上述结果表明，在提高切割效率和缩短洞制备时间成为可能后，预期Er：YAG激光应用的无痛治疗将在普通牙科诊所中建立。

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.