EVALUATION OF PROTECTION HYPOTHESIS FOR COMPOSITE WEAR

复合材料磨损保护假设的评估

• 批准号: 3222344
• 负责人: Stephen C. Bayne
• 金额: $ 19.26万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-12-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3222344
• 关键词: biomaterial evaluation; composite resins; dental material wear; human subject; tooth filling

The Operative Dentistry department at the University of North Carolina is the largest clinical research center for posterior composites and maintains the largest database of information on composite research restorations (9 projects involving 26 materials). We have recently presented evidence that (a) the wear rate of posterior composites decreases exponentially with time, (b) its prevalence and severity by site is 1st molars> 2nd molars> 2nd premolars> 1st premolars, and (c) wide or complex restorations are much more susceptible. Wear occurs on restorations at occlusal contact areas but is predominantly at contact free ares. Our results support the following "protection" hypothesis. Contact free wear is produced intraorally by > 0.1 um abrasive particles in food that selectively abrade the resin matrix of composites. Wear is limited by protection from closely spaced filler particles and from cavity preparation walls. Local filler particle spacing controls microscopic wear protection while cavity preparation size and location control macroscopic wear protection. This hypothesis appears to explain published wear results from most studies and sources. The objective of this proposal is to test this hypothesis with clinical data on wear rates and patterns from different tooth surfaces (occlusal, ridges and grooves, facial and lingual, interproximal), different tooth classes (molars, premolar, incisors), different composite types (conventional, hybrid, microfills), and different intraoral times (0- 0.5, 0.5-5, and 5-10 years). Clinical data on wear rates and patterns will be compared to laboratory data from modified DeGee abrasion tests to simulate clinical wear. Filler particle distribution, sizes, and interparticle spacing will be characterized for composites. Long term wear rate data is available from previous studies. Initial wear rate behaviors will be studied by inserting three posterior composites. Wear patterns will be characterized from epoxy replicas with the SEM. Local wear rates will be determined at margins with the Leinfelder scale, M-L scale, and SEM measurements. Information from clinical evaluations, cast ratings, and replica analyses will be statistically analyzed to compare in vitro wear and test the "protection" wear theory.

北卡罗来纳州大学的牙科手术系 最大的后部复合材料临床研究中心， 最大的综合研究成果信息数据库（9 项目涉及26种材料）。 我们最近提出的证据表明， (a)后复合材料的磨损率呈指数下降， 时间，（B）其患病率和严重程度按部位是第一磨牙>第二磨牙> 第二前磨牙>第一前磨牙，和（c）宽或复杂的牙列多 更容易受影响 磨损发生在咬合接触区的牙列上 但主要在无接触战神。 我们的研究结果支持这一 “保护”假说。 产生无接触磨损 口腔内通过食物中> 0.1 μ m的研磨颗粒选择性地研磨 复合材料的树脂基体。 磨损受到保护， 间隔的填料颗粒和空腔制备壁。 局部填料 颗粒间距控制微观磨损保护， 制备尺寸和位置控制宏观磨损保护。 这 这一假设似乎可以解释大多数研究中发表的磨损结果， 源 本提案的目的是检验这一假设， 不同牙齿表面磨损率和模式的临床数据 （咬合面、牙槽嵴和牙槽沟、面和舌、邻间）， 不同的牙齿类别（臼齿，前臼齿，门牙），不同的复合材料 类型（常规、混合、微填充）和不同的口内时间（0- 0.5、0.5-5和5-10年）。 磨损率和模式的临床数据将 与改良DeGee磨损试验的实验室数据进行比较， 模拟临床佩戴。 填料颗粒分布、尺寸和 将表征复合材料的颗粒间间距。 长期磨损率数据可从既往研究中获得。 初始磨损 将通过插入三个后验复合来研究速率行为。 将使用SEM对环氧树脂复制品的磨损模式进行表征。 局部磨损率将在Leinfelder量表的边缘处确定， M-L标度和SEM测量。 来自临床评价的信息， 铸造评级和复制品分析将进行统计分析， 比较体外磨损和测试“保护”磨损理论。