STEREOGRAMMETRIC ANALYSIS OF WEAR OF COMPOSITE

根据后方复合材料的ADA验收程序， 牙合磨损量在五年内不应超过250 临床服务。为了确定这个磨损量，无论是与 建议使用手写笔绘制表面的标准或轮廓图。 这些技术的局限性在于，它们要么使用糟糕的 定义的参考平面或表示不同状态的样本 磨损件必须安装在相同的位置。此外，这两种方法 缺乏将局部磨损变化与微观形态联系起来的能力 改变。 改进的磨损测量方法要求：1)建立 固定参考平面，2)对样品定位不敏感，3) 局部磨损的量化，以及4)局部分析的能力 微形态变化。 该项目的第一个目标是开发一种能够 在扫描电子显微镜照片上进行立体摄影测量和 将这些测量结果传送到能够产生3-D图像的微型计算机 被调查的表面的图样。将选择固定的解剖地标 用于确定参考平面。因此，本地变化在 被调查的表面和参考平面之间的距离可以是 识别和量化。当定位到这样的本地更改时， 这一区域的形态可以从扫描电子显微镜照片中确定。这个 第二个目标是将所提出的技术与基于 关于与标准的可视比较。五名牙医将估计深度 与标准相比，切割成金属表面的凹槽的数量。跟随 在这一估计中，将使用扫描电子显微镜立体摄影测量方法 确定这些凹槽的深度。这两项研究的结果 将对测定结果和扫描电子显微镜的可靠性进行比较 立体摄影测量方法将在潜在的研究中进行评估 复合树脂磨损。

According to the ADA acceptance program for posterior composite materials, occlusal wear should not exceed 250 Mum during a five year period of clinical service. To determine this amount of wear, either comparison with standards or profile mapping of the surface with a stylus are suggested. The limitations of these techniques are that they either use a poorly defined reference plane or that the samples representing different states of wear must be mounted in identical positions. In addition, both methods lack the ability to relate local wear changes to micro-morphological changes. Improved methods of wear measurement require: 1) the establishment of a fixed reference plane, 2) an insensitivity to specimen positioning, 3) the quantitation of localized wear, and 4) the capability to analyze local micro-morphological changes. The first objective of this project is to develop a system capable of performing stereophotogrammetric measurements on SEM photographs and transfer these measurements to a microcomputer capable of producing 3-D plots of the investigated surface. Fixed anatomic landmarks will be chosen for the determination of a reference plane. Thus, local changes in the distance between the investigated surface and the reference plane can be identified and quantified. When such a local change has been located, the morphology of this region can be determined from the SEM photographs. The second objective is to compare the proposed technique with a method based on visual comparison with standards. Five dentists will estimate the depth of grooves cut into metal surfaces by comparison with standards. Following this estimation, the SEM stereophotogrammetric method will be used to determine the depth of these grooves. The results of these two determinations will be compared and the reliability of the SEM stereophotogrammetric method will be evaluated for potential studies of composite resin wear.