生物改性是改善龋影响牙本质粘接的新方法，现有改性物生物相容性欠佳或使牙本质着色，限制了应用。申请人在前期工作发现，改性物没食子儿茶素没食子酸酯（EGCG）安全无着色性，能显著提高龋影响牙本质的粘接强度和显微硬度，并增强胶原耐酶解能力等。然而，其具体作用机理仍需深入探讨。因此，我们提出“EGCG生物改性改善龋影响牙本质粘接效果”的设想并研究其作用机理。本项目拟借助离体牙粘接模型，采用力学测试、显微镜检测、红外光谱分析以及液相芯片技术等验证EGCG改善龋影响牙本质粘接的作用，并进一步探讨改性对龋影响牙本质胶原、主要蛋白酶活性、继发龋发生以及再矿化的影响，明确EGCG生物改性改善龋影响牙本质粘接的作用和相关机制。研究结果有助于解决龋影响牙本质粘接效果不佳的问题，为今后研制新型功能性粘接材料和发展新粘接技术提供思路。

Dentin biomodification is an innovative approach to enhance and reinforce caries-affected dentin (CAD) bonding. Toxicity and dentin discoloration of present biomodification agents, however, affected their applications. Previously we have discovered and confirmed that epigallocatechin-3-gallate (EGCG) could improve CAD bonding efficacy, micro-hardness of CAD matrix as well as its anti-enzymatic degradation ability. However, the biomodification effects of EGCG on CAD bonding as well as the mechanism are not clearly understood. In this project, we aim to validate the effects of CAD biomodification using EGCG. The structure, molecule conformation of dentin collagen network as well as enzymatic resistance of CAD are analyzed; the consequent effects on remineralization of demineralized CAD, surface topography and micro-hardness are determined; the role of major proteinases inhibition effect and the occurrence of secondary caries of EGCG on CAD are also examined. This study will validate a novel biomodification approach to enhance bonding on CAD and revealed its mechanism, and is helpful to provide new direction for the development of new generation bonding agents.