Carvalho R M, Yoshiyama M, Horner J A, Pashley D H
Depto. Dentistica, FOB USP, Bauru, SP, Brazil.
Am J Dent. 1995 Oct;8(5):253-8.
This study investigated the hypothesis that the new resin-reinforced, light-cured ionomer cement (GIC) can develop mechanical retention by forming a hybrid layer in acid-etched dentin.
Dentin discs were obtained from extracted human third molars and sanded with 320 SiC abrasive paper. One third of the surface was acid etched with 10% maleic acid for 15 seconds, washed and gently air-dried for 5 seconds. ProBond primer from the VariGlass (VG) GIC kit was applied onto the acid-etched surface (A) and another third of the unetched surface (B) for 30 seconds. One third of the surface was not treated (C). VG GIC was then applied onto the ++entire surface of the disc. After 24 hours the discs were fractured along their diameters. One half of the fractured disc was highly polished at the interface and treated with 6N HCl for 30 seconds while the other half of the fractured specimen was left untreated. Both halves were viewed by SEM. In another part of the study, a micro-tensile bond strength (MTBS) test was carried out to compare the acid-etched group vs. the nonetched group.
SEM pictures revealed a well defined demineralized, resin-infiltrated zone approximately 3 micrometers in thickness for group (A) for both fractured and polished surface. Dentin surfaces that only received primer (B) showed an irregular zone 0.5 micrometers thick. Such a resin-infiltrated layer was resistant to HCl treatment. A gap was observed between the GIC and dentin in group (C). Polished interfaces appeared to be highly infiltrated. However, fractured interfaces revealed considerable porosity within the demineralized-infiltrated zone. MTBS results were (X +/- SD, MPa): 28.9 +/- 5.8 for the etched group and 24.5 +/- 4.9 for the nonetched group. This difference was statistically significant.
本研究探讨了一种假设，即新型树脂增强型光固化玻璃离子水门汀（GIC）可通过在酸蚀牙本质中形成混合层来实现机械固位。
从拔除的人类第三磨牙获取牙本质片，并用320号碳化硅砂纸打磨。将表面的三分之一用10%马来酸酸蚀15秒，冲洗并轻轻吹干5秒。将VariGlass（VG）GIC套装中的ProBond底漆涂覆在酸蚀表面（A）以及未酸蚀表面的另外三分之一（B）上30秒。表面的三分之一未作处理（C）。然后将VG GIC涂覆在牙本质片的整个表面。24小时后，沿牙本质片直径将其折断。将折断牙本质片的一半在界面处高度抛光，并用6N盐酸处理30秒，而另一半折断的标本不做处理。两半均用扫描电子显微镜观察。在该研究的另一部分，进行微拉伸粘结强度（MTBS）测试以比较酸蚀组和未酸蚀组。
扫描电子显微镜图片显示，对于折断和抛光表面的（A）组，有一个定义明确的脱矿质、树脂浸润区，厚度约为3微米。仅接受底漆处理的牙本质表面（B）显示出一个0.5微米厚的不规则区域。这样的树脂浸润层对盐酸处理具有抗性。在（C）组的GIC和牙本质之间观察到一个间隙。抛光的界面似乎有高度浸润。然而，折断的界面在脱矿质浸润区内显示出相当多的孔隙。MTBS结果为（X±标准差，MPa）：酸蚀组为28.9±5.8，未酸蚀组为24.5±4.9。这种差异具有统计学意义。
