Study on unpolymerized area in the surface layer of light activated composite resins

本研究的目的是确定表面区未聚合层的实际情况，并为其制定临床对策。因此，本文首先对表面未聚合层进行了研究，得到了以下结果。树脂固化后，修复的固化度随时间的延长而增加，但未聚合层仍留在修复体表面，这可能是修复体表面退化的原因。尝试了许多临床程序；使用基质、延长照射时间、在光单元末端使用白色尖端保护器等，这些技术以前被报道以提高修复体表面的固化程度。不幸的是，表面的固化程度显著提高，但不能防止涂层的出现。最好的方法是通过抛光和抛光工序来去除Pr…上的涂层更重要的时刻。因此，为了确定未聚合层的实际范围，必须通过诺普硬度测量作为参数来检测商品表面区域中相对合适的固化区域。因为，未聚合或固化不充分的区域可能出现在表层。从辐照表面以下区域到辐照方向的深度进行了诺氏硬度测量，得到了硬度-深度曲线。根据曲线上的峰值硬度，可以确定必须通过抛光去除的树脂产品的深度。结论如下：首先，光活化复合树脂应该在型腔中过度填充(约0.5 mm)。初始固化后，必须通过抛光或抛光程序去除多余的材料。因此，可以在修复体上暴露具有最佳表面纹理的表面。较少

The purpose of this study was to determine the actual situation of the unpolymerized layer in the surface area and make up some clinical counterplan for it. Therefore, Firstly, the study on the unpolymerized layer in the surface was conducted.The following results were obtained. After initial setting of the resin, the degree of cure for the restoration continues to increase with time, but the unpolymerized layer continuously remaines at the surface of restoration, that might be the cause of surface degradation. Many clinical procedures ; using a matrix, prolonged irradiation time, using a white tip protector on the light unit end, and so on , which techniques were previously reported to improve the degree of cure on the surface of the restoration, were attempted. Unfortunately, the degree of cure at the surface area was remarkably improved but the apperance of the layer could not be prevented. It is the best way that the removal of layer by finishing and polishing procedures, at the pr … More esent moment. Therefore, in order to determine the actual range of the unpolymerized layer, the relatively properly cured area in the surface region of the commercial products has to be detected by means of the Knoop hardness measurement as a parameter. Because, the area where is unpolymerized or inadequately cured might be appeared at the surface layer. The Knoop hardness measurements were carried out from the area just below the irradiation surface to the depths along the irradiation direction, to obtain the hardness vs. depth curve. From the peak hardness on the curve, it is possible to determine the depth of resin products which must be removed by polishing.The conclusions are as follows.At first, the light activated composite resin should be overfilled ( approximately 0.5 mm ) in the cavity. After initial setting, the excess material must be removed by finishing or polishing procedure. Consequently, it is possible to expose the surface having the best surface texture on the restoration. Less