WEAR DETERMINATION BY USE OF SHADOW-MOIRE

根据ADA后部验收程序 复合材料，咬合磨损不应超过250亩 在五年的临床服务期间。要确定这一点 磨损量，无论是与标准相比还是高度 使用了复杂而昂贵的技术。缺点是 这些技术要么太不准确，要么 太复杂了，不能被普遍接受。为了方便 精确的临床磨损测定，至少在几个月内 咬合面上任何一点的微米，一条阴影云纹 建议对技术进行评估，并与 计算机化地图绘制。 这个项目的第一个目标是找到合适的栅格 尺寸为了准确，但同时又易于阅读 阴影-莫尔条纹图案。条纹将被记录在 照相材料和放大。通过使用数字转换器，x-，y-， 和z坐标将被确定为在 牙齿表面的照片。通过使用可用的软件 对于坐标变换，这些点将定向 相对于参考平面，该参考平面由这些值确定 三个参照点。然后这些信息将被处理 使用可用的软件来生成计算机图形，在该软件上 变量，如参照平面和曲面之间的体积 可以确定修复的范围。 在最初的技术开发部分之后，研究将 是为了确定尖点等因素如何 坡度、尖点长度、相机扭曲和由以下因素引起的扭曲 放大过程会影响阴影的精度 云纹技术。这些决定将在 已加工的具有已知几何形状的金属齿模。

According to the ADA acceptance program for posterior composite materials, occlusal wear should not exceed 250 mu during a five year period of clinical service. To determine this amount of wear, either comparison with standards or highly sophisticated and expensive techniques are used. The drawbacks with these techniques are that they are either too inaccurate or too complex to become generally accepted. In order to facilitate precise clinical wear determinations, at least within a few microns at any point on the occlusal surface, a shadow-moire technique is suggested to be evaluated and used together with computerized mapping. The first objective with this project is to find the right grating sizes in order to get precise but at the same time easy to read shadow-moire fringe patterns. The fringes will be recorded on photographic material and enlarged. By use of a digitizer, x-, y-, and z-coordinates will be determined for different points on the photograph of the tooth surface. By use of an available software for coordinate transformation, these points will be oriented relative to a reference plane which is determined from the values of three reference points. This information will then be treated with available software to produce computer graphics, on which variables such as volume between refernce plane and the surface of the restoration can be determined. Following the initial technique developmental section, studies will be conducted in order to determine how factors such as cusp slopes, cusp lengths, camera distortion, and distortion caused by the enlargement process influence the accuracy of the shadow moire technique. These determinations will be conducted on machined metal tooth dies with known geometry.