Effects of Biofilm Activities and Dental Resin Composite Compositions on the Deve

描述（由申请人提供）：本项目的主要目标是更好地了解导致继发性龋齿发展的因素，并确定增加树脂复合修复体使用寿命的策略。由于继发性龋齿的修复置换占据了牙医实践的很大一部分。1999年，牙医在这个国家放置了8600万个复合材料，2006年放置了1.227亿。现在平均更换时间只有5.7年。大量修复的长期完整性的显著改善可以为美国人民节省（通过减少更换修复的成本）许多倍于支持这项工作所需的资金。成功地进行这一努力，使千百万人受益，具有重大意义。我们建议研究生物膜活性和牙树脂复合成分对继发性龋发生的影响。我们将使用一个生物反应器模型，利用口腔环境中的条件来了解微生物生物膜、唾液膜和循环载荷在继发性龋齿形成过程中的作用。虽然生物反应器模型建立了循环再矿化/脱矿攻击的条件，但我们将使用各种口腔模拟挑战和分析方法来评估它们对复合修复牙齿的影响。我们假设修复边缘缺陷的主要原因包括：树脂聚合收缩引起的界面应力，唾液酯酶，产酸微生物产生的生物膜，以及循环载荷和口腔热波动引起的变形。这些会导致随后的染色、继发性龋齿、骨折或其他问题。该项目的长期目标是鉴定和制备一种最佳交联复合树脂，可以修复缺陷牙齿并抵抗环境降解（目标1）；确定聚合收缩对牙-复合材料界面降解发展的影响（目标2）；了解唾液膜和微生物生物膜在复合修复体继发性龋齿的病因学中的作用（目标3）；并与氟化物疗法协同发展有益的生物膜，有可能延缓继发性龋齿的发生（目标4）。我们的目标是了解决定修复时间长度的物理、化学和生物因素。有了这一认识，我们将开发更稳定的树脂基复合材料和方法，以防止限制复合材料修复成功的衰变。

DESCRIPTION (provided by applicant): The primary objectives of this project are to better understand the factors that lead to the development of secondary caries and to identify strategies to increase the service life of resin composite restorations. Restoration replacements due to secondary caries occupies a large portion of the dentist's practices. In 1999, 86 million composites were placed by dentists in this country and 122.7 million in 2006. The average replacement time is now only 5.7 years. Significant improvements in the long-term integrity of so many restorations could save the American people (by reducing costs of replacing restorations) many times the amount of money required to support this work. There is tremendous significance in the successful pursuit of this endeavor to benefit so many millions of people. We propose to study the effects of biofilm activity and dental resin composite compositions on the development of secondary caries. We will use a bioreactor model that utilizes conditions found in the oral environment to understand the role of microbial biofilms, salivary pellicles, and cyclic loading in the processes of secondary caries formation. While the bioreactor model establishes the conditions for the cyclic remineralization/demineralization attacks, we will use a variety of oral-simulating challenges and analytical methods to assess their effects on composite-restored teeth. We hypothesize that major contributors to defects at restoration margins include: interfacial stresses from contractions induced by polymerization shrinkage of resins, salivary esterases, acidogenic microbe-generated biofilms, and deformations from cyclic loading and oral thermal fluctuations. These can lead to subsequent staining, secondary caries, fractures, or other problems. The long-term goals of this project are to identify and prepare an optimally cross-linking composite composition resin that can restore defective teeth and defy environmental degradation (Aim 1); determine the effects of polymerization shrinkage on the development of degradation at the tooth-composite interface (Aim 2); understand the roles of salivary pellicles and microbial biofilms in the etiology of secondary caries' association with composite restorations (Aim 3); and develop beneficial biofilms in synergy with fluoride therapies that have the potential of retarding the onset of secondary caries (Aim 4). Our goal is to understand the physical, chemical and biological factors that determine the length of time a restoration lasts. With this understanding, we will develop more stable resin-based composites and methods to prevent the decay that limits the success of composite restorations. PUBLIC HEALTH RELEVANCE: This project is focused on developing strategies to increase the service life of resin composite restorations. Our goal is to understand the physical, chemical and biological factors that determine the length of time a restoration lasts. With this understanding, we will develop more stable resin-based composites and methods to prevent the decay that limits the success of composite restorations.