Determinants of the Durability of Resin-Dentin Bonds

描述：如果树脂复合材料是银填充物（牙科汞合金）的一种经济有效的替代品，树脂和牙本质之间的粘合剂粘合必须得到改善，以增加其耐久性。为了使树脂粘附在牙本质上，用酸蚀法除去矿物相。我们假设持久的树脂-牙本质结合需要稳定的树脂完全取代失去的矿物体积。这样的树脂吸收需要胶原原纤维基质被水拉伸。疏水性树脂在用作树脂复合材料的基质时表现出更稳定的性能。然而，如果疏水单体应用于饱和水的牙本质，它们会发生相变，不能穿透基质。亲水单体更成功，但这些键随着时间的推移被水解而恶化。我们最近的研究表明，大多数商业粘合剂会导致水饱和的胶原基质坍塌，这主要是由于它们的溶剂具有Hoy的溶解度参数，h -键力（hbb）太低，无法阻止胶原原纤维之间的肽间h -键，这种键是在单体渗透过程中溶剂取代水时发生的。我们认为这些纤维间空间的大小是至关重要的，因为它们既是单体浸润的扩散通道，也是胶原原纤维的保护性树脂涂层。如果纤维间隙塌陷，几乎没有树脂来保护原纤维。我们对溶剂和单体的hbb值进行了排序。乙醇已被证明可以最大限度地减少基质坍塌，同时作为粘合剂单体的优良溶剂。我们制定了一系列基于其hbb值具有一系列疏水性/亲水性的粘合剂共单体，以测试疏水性树脂比目前的亲水性树脂提供更持久的树脂牙本质键的假设。提出的研究提供了一个系统的实验序列，从一系列疏水性到亲水性树脂中选择单体/溶剂组合，最大限度地减少基质的坍塌，最大化胶原纤维之间的树脂吸收，优化树脂牙本质结合强度，同时最大限度地减少树脂密封牙本质对水的渗透性。我们希望尽量减少吸水性，并最大限度地提高树脂-牙本质键的长期耐久性。这将为设计更耐用的树脂-牙本质结合提供重要的新见解，可以证明树脂基后牙复合材料的放置是合理的。

DESCRIPTION: If resin composites are to provide a cost-effective alternative to silver fillings (dental amalgams), the adhesive bond between resins and dentin must be improved to increase its durability. To achieve adhesion of resins to dentin, the mineral phase is removed by acid etching. We posit that durable resin-dentin bonds require that stable resins fully replace the lost mineral volume. Such resin uptake requires extension of the collagen fibril matrix by water. Hydrophobic resins have been shown to be more stable when used as matrices for resin composites. Nevertheless, if hydrophobic monomers are applied to water-saturated dentin, they undergo phase changes and cannot penetrate the matrix. Hydrophilic monomers are more successful, but these bonds deteriorate over time by hydrolysis. Our recent work demonstrated that most of commercial adhesives cause a collapse of the water-saturated collagen matrix, that is largely due to their solvents having Hoy's solubility parameters for H-bonding forces (HHB) that are too low to prevent interpeptide H-bonding between collagen fibrils that occurs as the solvents replace water during monomer infiltration. We believe that the size of these interfibrillar spaces is critical because they serve both as diffusion channels for monomer infiltration and provide a protective resin coating for collagen fibrils. If the interfibrillar spaces collapse, there is little resin to protect the fibrils. We have ranked solvents and monomers for their HHB values. Ethanol has been shown to minimize matrix collapse, while acting as an excellent solvent for adhesive monomers. We have formulated a series of adhesive co-monomers that have a range of hydrophobicities/ hydrophilicities based on their HHB values, to test the hypothesis that hydrophobic resins provide more durable resin dentin bonds than current hydrophilic resins. The proposed studies provide a systematic sequence of experiments to select monomer/solvent combinations from a range of hydrophobic to hydrophilic resins, that minimize collapse of the matrix, maximize resin uptake between collagen fibrils, optimize resin dentin bond strength, while minimizing the permeability of resin-sealed dentin to water. We expect to minimize water sorption and maximize the long-term durability of resin-dentin bonds. This should provide important new insight into designing more durable resin-dentin bonds that can justify the placement of resin-based posterior composites.