BIOPSY AND ANALYSIS OF 5 TO 10 YEAR OLD COMPOSITES

牙科手术临床研究计划在大学 北卡罗来纳州拥有最大的牙科信息数据库， 复合研究患者。 在过去10年中，15个项目 进行了。 现在很多孩子的年龄都在5到10岁之间 很快就需要更换。 这提供了一个独特的 有机会删除、恢复和分析完全 具有临床评价数据的特征和悠久历史。 的 本提案的目的是使用（a）临床评价磨损数据，（B） 来自活组织检查的显微结构和显微化学数据，以及（c）已发表的 性能值，以检验当前复合材料磨损理论的有效性。 将从预先选定的患者中采集活检标本，以（1）解释 高磨损率与低磨损率患者之间的差异，（2） 评估特定的口内定位因素，例如前与后， 磨牙与前磨牙，1类与2类，以及咬合接触面积与 非接触区域，和（3）评估早期和早期之间磨损率的差异 1至3年的使用期和长时间使用后的磨损率 服务5至10年。 然后将活检组织切成两半并抛光，以提供样本用于 SEM显微结构分析和FTIR显微化学分析。 SEM 微裂缝、孔隙和裂缝的测量将用于评估 目前的机械磨损理论。 化学成分的FTIR分析 和转化程度将被用来评估当前的化学品 退化理论 这两种情况下的信息都将收集在两个 表面和内部区域进行比较。 来自临床评价、实验室分析和已发表文献的信息 性能将进行统计学检查，以确定磨损与 因果关系。

The Operative Dentistry Clinical Research Program at the University of North Carolina maintains the largest database of information on dental composite research patients. During the past 10 years, 15 projects have been conducted. Many of the restorations are now in the 5 to 10 year old category and will require replacement shortly. This provides a unique opportunity to remove, recover, and analyze restorations that are fully characterized and have a long history of clinical evaluation data. The objective of this proposal is to use (a) clinical evaluation wear data, (b) microstructural and microchemical data from biopsies, and (c) published property values to test the validity of current composite wear theories. Biopsies will be collected from pre-selected patients to (1) explain differences between patients with high wear rates vs low wear rates, (2) evaluate specific intraoral location factors such as anterior vs posterior, molar vs premolar, class 1 vs class 2, and occlusal contact areas vs non-contact areas, and (3) evaluate differences in wear rates between early periods of service at 1 to 3 years and wear rates after long periods of service from 5 to 10 years. Biopsies will then be sectioned in half and polished to provide samples for both SEM microstructural analyses and FTIR microchemical analyses. SEM measurements of microfractures, pores, and cracks will be used to assess current mechanical wear theories. FTIR analyses of chemical composition and degree of conversion will be used to evaluate current chemical degradation theories. Information in both cases will be collected on both superficial and interior zones for comparison. Information from clinical evaluations, laboratory analyses, and published properties will be statistically examined for correlations of wear with causal relationships.