Laser Raman Micro-spectroscope Observation for the Analysis of Resin-dentin Interdiffusion Zone

目前认为，树脂复合材料与牙齿基材的粘结依赖于粘结树脂渗透到多孔区，建立对酸蚀表面的微机械保持。如果粘合树脂不能穿透脱矿的牙齿基材，那么这一层内的多孔层将暴露在口腔液体中，容易降解。本研究的目的是探讨自酸蚀底漆的使用时间对树脂对牙本质的渗透性和牙本质粘结强度的影响。制成粘接试件后，切开粘接界面。然后用粒度为1.0μm的金刚石浆料对切片表面进行抛光。沿着垂直于牙齿/树脂界面的一条线连续记录了拉曼光谱。样机工作台在计算机控制的X-Y精密工作台上以0.2μm的步长移动。记录了牙齿和固化粘接树脂样品的附加光谱，以供参考。计算了牙釉质/树脂粘结区中羟基磷灰石(960 cm-1，P-O)、粘结剂(640 cm-1，芳香环)和烷基(1450 cm-1，C-H)的相对含量。拉曼光谱显示，脱矿牙本质宽度随处理时间延长而增加。各组分的渐变模式不同。此外，牙齿/树脂界面代表粘结剂从树脂侧到牙齿侧的逐渐过渡。结果表明，酸蚀牙釉质中的树脂渗入不均匀，不同粘接系统的树脂渗入程度不同。

Adhesion of resin composites to tooth substrate is currently believed to rely on the infiltration of bonding resin into the porous zone, establishing micro-mechanical retention to etched surface. If adhesive resin does not penetrate the demineralized tooth substrate, then the porous layer within this layer will be exposed to oral fluids and vulnerable to degradation. The purpose of this study was to investigate the effect of self-etching primer application duration on resin penetration into dentin and dentin bond strength. After making bonded specimens, sectioned through the bonded interface. The sectioned surfaces were then polished with diamond pastes down to 1.0 μm particle size. Raman spectra were successively recorded along a line perpendicular to the tooth/resin interface. The sample stage was moved in steps of 0.2 μm on a computer controlled X-Y precision table. Additional spectra from samples of tooth and cured bonding resins were recorded for reference. The relative amounts of the hydroxyapatite (960cm-1,P-O), bonding agent (640cm-1,aromatic ring), and alkyl group (1450cm-1,C-H) in the enamel/resin bonding area were calculated. From the Raman spectroscopy, the widths of demineralized dentin increased with prolonged treatment time. The patterns of gradual transition of components were different among the groups. Furthermore, the tooth/resin interface represents a gradual transition of bonding agent from resin side to tooth side. From the results of this study, nonuniform resin infiltration into the etched enamel was detected and the degree of resin infiltration was different among the bonding systems used.