Li He, Li Tianbo, Li Xiuying, Zhang Zhimin, Li Penglian, Li Zhenling
Department of Hospital of Stomatology, Jilin University Changchun, China.
Int J Clin Exp Med. 2015 Jul 15;8(7):10793-803. eCollection 2015.
Matrix metalloproteinases (MMPs) have been studied extensively, and MMP inhibitors have been used as dental pretreatment agents prior to dentin bonding because they reduce collagen fiber degradation and improve bonding strength. However, morphologic characteristics of the collagen network after etching and of the post-adhesive dentin hybrid layers (DHL) after MMP inhibitors pretreatment have not been evaluated. Thus, we investigated demineralized dentin pretreated with chlorhexidine (CHX) and minocycline (MI) in an etch- and -rinse adhesive system with field emission scanning electron microscopy (FESEM) and immuno-gold labeling markers to observe the collagen network and DHL. FESEM revealed after CHX and MI, a demineralized dentin surface and improved collagen network formation, reduced collagen degradation, and distinct gold-labeling signals. Applying adhesive after either MMP inhibitor created a better dentin interface as evidenced by immuno-gold staining, better adhesive penetration, and higher DHL quality. With microtensile bond strength tests (µTBS) we estimated bonding strength using µTBS data. Immediate µTBS was enhanced with MMP inhibitor application to the bonding surface, and the CHX group was significantly different than non-treated etched surfaces, but no significant change was detected in the MI group. Surface micromorphology of the fractured dentin resin restoration showed that the CHX group had a better resin and dentin tube combination. Both MMP inhibitors created uniform resin coverage. Thus, morphologic results and µTBS data suggest that CHX and MI can inhibit MMP activity, improve immediate bonding strength, and enhance dentin bonding stability with an etch- and -rinse adhesive system.
基质金属蛋白酶（MMPs）已得到广泛研究，MMP抑制剂已被用作牙本质粘结前的牙科预处理剂，因为它们可减少胶原纤维降解并提高粘结强度。然而，蚀刻后胶原网络的形态特征以及MMP抑制剂预处理后粘结后牙本质混合层（DHL）的形态特征尚未得到评估。因此，我们使用场发射扫描电子显微镜（FESEM）和免疫金标记标记物，在酸蚀冲洗粘结系统中研究了用氯己定（CHX）和米诺环素（MI）预处理的脱矿牙本质，以观察胶原网络和DHL。FESEM显示，经CHX和MI处理后，脱矿牙本质表面、胶原网络形成改善、胶原降解减少且有明显的金标记信号。用任一种MMP抑制剂处理后再应用粘结剂，均可形成更好的牙本质界面，免疫金染色、更好的粘结剂渗透和更高质量的DHL均证明了这一点。通过微拉伸粘结强度测试（µTBS），我们利用µTBS数据估算粘结强度。在粘结表面应用MMP抑制剂可提高即时µTBS，CHX组与未处理的蚀刻表面有显著差异，但MI组未检测到显著变化。断裂的牙本质树脂修复体的表面微观形态显示，CHX组的树脂与牙本质小管结合更好。两种MMP抑制剂均产生均匀的树脂覆盖。因此，形态学结果和µTBS数据表明，CHX和MI可抑制MMP活性，提高即时粘结强度，并增强酸蚀冲洗粘结系统中牙本质粘结的稳定性。
