Multifunctional, Non-thermal Plasmas for Long-lasting Dental Adhesion

描述（由申请人提供）：本提案的科学目标是采用非热等离子体诱导的新表面/界面化学/功能，以实现坚固耐用的牙本质粘附，从而显著延长树脂基牙齿修复体的寿命。这项研究源于修复牙科长期面临的严峻挑战：基于复合树脂的牙科修复具有极高的失败率。过早失效的一个主要原因是复合树脂和底层牙本质之间缺乏紧密和持久的粘附。目前最先进的粘结技术不能形成紧密的树脂/牙本质粘合是由于三个主要因素。首先，树脂和牙本质胶原之间的粘合很差，这种粘合依赖于粘合树脂与暴露的胶原纤维的渗透和随后的缠结。微机械互锁机制本质上是有问题的，因为不充分的渗透、不完全的聚合和溶剂/水溶胀都阻止了紧密粘合的形成。其次，牙本质基质的稳定性和质量通常较差。当复合树脂附着的基础本身不稳定时，实现持久的修复不仅具有挑战性，而且是不可能的。第三，渗透树脂聚合物的强度和质量通常较差，主要是由于当前粘合剂在口腔环境下的不完全聚合。在这项提案中，将利用具有明智设计的化学物质的多功能非热等离子体来同时解决所有三个关键问题。这种新颖的多功能等离子体技术具有以下独特的特征/功能：1）对腔体区域进行消毒，消除残留的引起龋齿的微生物; 2）能够将氟化物直接递送到牙本质基质以抑制脱矿/细菌攻击，从而减少复发性龋齿并改善牙本质基质稳定性; 3）提供可控的等离子体化学以原位和按需定制表面能，以增强粘合剂渗透到暴露的胶原原纤维中; 4）参与树脂基体中的网络聚合和交联反应，从而提高树脂基体的单体/聚合物转化率和交联密度，从而产生更有粘性和抗降解的树脂基体; 5）通过增强的树脂保护来改善牙本质基质对生物降解的稳定性; 6）在粘合剂树脂和胶原纤维之间产生化学/共价键合，从而增强粘合剂/牙本质粘合强度。将利用各种表征技术来彻底阐明等离子体处理对牙本质和粘合剂表面/界面的影响。我们的目标不仅是确认设计原则和工程等离子体技术/化学品的工作，而且还要深入了解它们是如何以及为什么工作的。

DESCRIPTION (provided by applicant): The scientific objective of this proposal is to employ new surface/interface chemistries/functionalities induced by non-thermal plasmas for robust and durable dentin adhesion, thus significantly extending the longevity of resin-based tooth restorations. The proposed research stems from the critical challenge long facing restorative dentistry: dental restorations based on composite resins have a prohibitively high failure rate. One primary reason for the premature failure is the lack of a tight and long-lasting adhesion between the composite resin and the underline dentin. The inability of the current state-of-the-art bonding techniques to form a tight resin/dentin adhesion is due to three major factors. First, the bonding between resin and dentin collagen, which relies on the infiltration and subsequent entanglement of adhesive resins with exposed collagen fibrils, is poor. The micromechanical interlocking mechanism is intrinsically problematic as insufficient penetration, incomplete polymerization and solvent/water swelling all prohibit the formation of a tight adhesion. Second, the stability and quality of the dentin substrates is often poor. When the foundation to which composite resins adhere is itself shaky, achieving long-lasting restoration is not just challenging, but impossible. Third, the strength and quality of infiltrated resin polymers is usually poor due chiefly to the incomplete polymerization of current adhesives under oral environment. In this proposal, multifunctional non-thermal plasmas with judiciously engineered chemistries will be utilized to simultaneously address all three critical issues. Such a novel and multifunctional plasma technique has the following unique features/functions: 1) sterilize the area of cavity, eliminating residual caries-causing microorganisms; 2) enable direct fluoride delivery to dentin substrates to inhibit demineralization/bacterial attack, thus reduce recurrent caries and improve dentin substrate stability; 3) provide controllable plasma chemistries to tailor the surface energy in-situ and on-demand for enhanced adhesive penetration into exposed collagen fibrils; 4) participate in network polymerization and crosslinking reactions in resin matrix, consequently increase the monomer/polymer conversion and crosslinking density of the resin matrix and thus producing a more cohesive and degradation-resistant resin matrix; 5) improve the stability of the dentin substrates against biodegradation through enhanced resin protection; 6) yield a chemical/covalent bonding between adhesive resins and collagen fibrils, thus enhancing the adhesive/dentin bond strength. Various characterization techniques will be utilized to thoroughly elucidate the plasma treatment effects on the dentin and adhesive surface/interface. The goal is not only to confirm that the design principles and the engineered plasma technology/chemistries work, but also gain deep understanding into how and why they do.