低温等离子用于牙本质胶原纤维改性及“干粘接”的机制研究

In today’s dental practice, resin bonding is an increasingly common procedure, especially when aesthetic considerations are of priority. However, the longevity of dentin bonding has long been criticized. Dentin bonding is essentially a hybridization process in which dental substrate and adhesive resin interact with each other through an exchange process. Nowadays, dentin bonding is based on water “wet-bonding” philosophy. However, the excess water will induce suboptimal polymerization of dental adhesives, phase separation, and nanoleakage, which will influence the longevity of resin-dentin interfaces. Recently, several researches focused on topic of dentin “dry-bonding”. Our preliminary study has confirmed that dry-bonding based on cold plasma technique improved the penetration of the adhesive and increased immediate dentin bond strength. The aim of this study was to investigate whether cold plasma could be used for dry-bonding of dental adhesive, and improving the bond strength and durability. The effect and mechanism of cold plasma to improve dentin bonding would also be studied to determine the optimal treatment strategies.

现代牙科治疗中,树脂粘接的应用十分广泛,但是牙本质粘接却容易发生老化。牙本质粘接实质上是树脂粘接剂渗入并固化于脱矿的胶原纤维网从而形成混合层的过程,目前主要基于“湿粘接”的理念进行粘接。但是水的存在会影响树脂粘接剂的渗透和固化,导致胶原纤维暴露,后者又在含水环境下被蛋白酶水解,造成粘接老化。因此,消除水的不利影响对改善粘接效果和耐久性有重要意义。本课题组利用低温等离子对脱矿牙本质干燥后进行树脂粘接,已初步证实其可行性。“干粘接”的目的是消除胶原纤维网中水对树脂渗透的影响,降低胶原纤维暴露以及被蛋白酶水解的风险,减少树脂粘接剂吸水后发生的塑化和降解,改善粘接效果和耐久性。低温等离子的应用为牙本质“干粘接”提供了新途径。本课题将进一步深入研究基于低温等离子技术的牙本质“干粘接”的效果和机制,探索适合临床应用的参数,为最终实现牙本质“干粘接”提供理论和研究基础。

在现代口腔医学微创理念指引下，粘接修复的应用日益广泛。然而，当前基于“湿粘接”理念的牙本质粘接，由于界面混合层中的水会影响树脂粘接剂渗透和固化，导致胶原纤维暴露，后者又在含水环境中被蛋白酶水解，最终不可避免地发生粘接老化。本项目在国内外率先采用新型大气压冷等离子体处理脱矿后的牙本质粘接界面，研究评价了牙本质胶原纤维的三维形貌、亲水性及其对树脂粘接剂渗透的影响，并评价了即刻粘接强度和粘接老化性能。结果表明，新型大气压冷等离子体处理脱矿牙本质胶原纤维，可以良好保存胶原纤维舒展、立体的三维结构，可以显著增强牙本质胶原纤维的表面润湿性，最终粘接后形成更加致密、完整的混合层，并有效增加牙本质小管内的树脂突长度。大气压冷等离子体处理牙本质30秒可将即刻粘接强度提高1.6倍，并能显著提高粘接界面稳定性，老化粘接强度提高至2.4-3.9倍。本项目开创了一种牙本质粘接抗老化的有效方案，显著改善粘接效果。该方法相比于其它改善牙本质粘接性能和耐久性的方法更安全、简便，更适合临床应用，已达到国内外先进水平。本项目的研究成果将用于牙体缺损粘接修复领域，有望提高牙本质粘接修复的长期效果，减少牙体缺损修复再治疗的几率。