RESTORATIVE MATERIAL WEAR FACTORS

聚合物基修复材料的分解通常是由于 导致磨损的化学和物理应力的组合。 目前， 临床磨损行为最可靠的预测因素是精心设计的 临床研究 尽管在某些情况下可以将 这些研究的结果与体外试验，这种相关性不 始终为预测磨损提供可靠的科学依据。 认为疲劳诱发磨损是机械加工中的一个重要现象， 一些修复材料的降解，特别是“微填充” 复合材料，当用于应力轴承的情况下。 这是相对 被忽视的修复材料研究领域。 本研究将采用几种新的方法， 在了解疲劳引起的磨损的聚合物材料中使用， 修复牙科 一系列类似于目前用作基体的树脂材料 用于牙科复合材料的树脂将由工业承包商制备。 一些样品将填充少量的硅烷化胶态二氧化硅， 如在实践中控制基质材料的粘度所做的那样。 所有 样品的特征在于固化度和Tg。 针- 盘上磨损测试将利用适当的触针几何形状， 亚表面疲劳磨损 动态拉伸和剪切疲劳测试将 按照相关ASTM规范进行。 利用这些特性， 测量，有限元建模技术将用于模拟销上， 盘磨损行为。 最后，疲劳断裂表面、磨损表面和 磨损碎片将采用经典和分形几何 方法.

The breakdown of polymer-based restorative materials is often due to a combination of chemical and physical stresses that cause wear. Presently, the most reliable predictor of clinical wear behavior is the well-planned clinical study. Although it is possible in some cases to correlate the results of such studies with an in-vitro test, such correlations do not always provide a sound scientific basis for predicting wear. It is believed that fatigue induced wear is an important phenomenon in the degradation of some restorative materials, particularly the "microfilled" composites, when used in a stress-bearing situation. This is relatively neglected area of restorative materials research. Several novel approaches will be employed in this study in order to arrive at an understanding of fatigue-induced wear of polymer materials used in restorative dentistry. A series of resin materials similar to those presently used as matrix resins for dental composites will be prepared by an industrial contractor. Some samples will be filled with low amounts of silanated colloidal silica, as is done in practice to control the viscosity of matrix materials. All samples will be characterized with respect to degree of cure and Tg. Pin- on-disc wear testing will utilize an appropriate stylus geometry to induce subsurface fatigue wear. Dynamic tensile and shear fatigue testing will be done following relevant ASTM specifications. Employing the properties thus measured, finite element modeling techniques will be used to mimic pin-on- disc wear behavior. Finally, fatigue fracture surfaces, wear surfaces, and wear debris will be characterized using classical and fractal geometric methods.