Determinants of the Durability of Resin-Dentin Bonds

描述：如果树脂复合体要提供一种成本效益高的替代银填充物(牙科汞合金)的方法，就必须改善树脂与牙本质之间的粘结，以提高其耐久性。为了实现树脂与牙本质的粘接，通过酸蚀去除矿物相。我们假设，耐用的树脂-牙本质粘结剂需要稳定的树脂完全取代丢失的矿物质体积。这样的树脂吸收需要用水延长胶原原纤维基质。疏水树脂在用作树脂复合材料的基质时更稳定。然而，如果将疏水单体应用于水饱和的牙本质，它们会发生相变，不能穿透基质。亲水性单体更成功，但随着时间的推移，这些键会因水解而恶化。我们最近的工作表明，大多数商用胶粘剂会导致水饱和的胶原基质崩解，这在很大程度上是因为它们的溶剂具有Hoy的氢键力(HHB)的溶解度参数，太低，无法阻止在单体渗透过程中溶剂取代水时发生的胶原纤维之间的肽间氢键。我们认为这些纤维间隙的大小是至关重要的，因为它们既是单体渗透的扩散通道，又为胶原纤维提供了一层保护树脂涂层。如果纤维间隙塌陷，几乎没有树脂来保护纤维。我们对溶剂和单体的HHb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秀溶剂。我们配制了一系列基于HHB值的具有一系列疏水性/亲水性的粘合剂共单体，以测试疏水树脂比目前的亲水树脂提供更持久的树脂牙本质结合这一假设。建议的研究提供了一系列系统的实验，从疏水性到亲水性树脂中选择单体/溶剂组合，以最大限度地减少基质的坍塌，最大限度地增加胶原纤维之间的树脂吸收，优化树脂牙本质粘结强度，同时最大限度地减少树脂密封牙本质对水的渗透性。我们希望最大限度地减少吸水率，最大限度地提高树脂-牙本质粘结剂的长期耐用性。这将为设计更耐用的树脂-牙本质粘结剂提供重要的新见解，从而证明树脂基后牙复合体的放置是合理的。

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.