Carvalho Ricardo M, Chersoni Stefano, Frankenberger Roland, Pashley David H, Prati Carlo, Tay Franklin R
Department of Operative Dentistry, Bauru School of Dentistry, University of São Paulo, Brazil.
Biomaterials. 2005 Mar;26(9):1035-42. doi: 10.1016/j.biomaterials.2004.04.003.
This study provided morphological evidence that discrepancies between the depth of demineralisation and the depth of resin infiltration can occur in some mild self-etch adhesives. Sound dentine specimens derived from extracted human third molars were bonded with 5 one-step and 5 two-step self-etch adhesives. One millimeter thick slabs containing the resin-dentine interfaces were immersed in 50 wt% aqueous ammoniacal silver nitrate and processed for TEM examination. A zone of partially etched but uninfiltrated dentine was identified beneath the hybrid layers in the milder versions of both one-step and two-step self-etch adhesives. This zone was characterised by the occurrence of silver deposits along the interfibrillar spaces of mineralised collagen fibrils. The silver infiltrated interfibrillar spaces were clearly identified from the one-step self-etch adhesives Xeno III, iBond, Brush&Bond and the experimental adhesive, and were thinner and only occasionally observed in the two-step self-etch adhesives Clearfil SE Bond and Clearfil Protect Bond. The more aggressive one-step and two-step adhesives that exhibit more abrupt transitions from completely demineralised to mineralised dentin were devoid of these silver-infiltrated interfibrillar spaces beneath the hybrid layers. Incomplete resin infiltration observed in some self-etch adhesives may be caused by the reduced etching potential of the acidic monomers toward the base of hybrid layers, or the presence of acidic but non-polymerisable hydrolytic adhesive components, creating potential sites for the degradation of the bonded created by these self-etch adhesives.
本研究提供了形态学证据，表明在一些轻度自酸蚀粘结剂中，脱矿深度与树脂渗入深度之间可能存在差异。从拔除的人类第三磨牙获取的健康牙本质标本，用5种一步法和5种两步法自酸蚀粘结剂进行粘结。将含有树脂-牙本质界面的1毫米厚切片浸入50 wt%的氨性硝酸银水溶液中，并进行透射电镜检查。在一步法和两步法自酸蚀粘结剂的较温和版本的混合层下方，发现了一个部分蚀刻但未渗入的牙本质区域。该区域的特征是在矿化胶原纤维的纤维间空间出现银沉积。从一步法自酸蚀粘结剂Xeno III、iBond、Brush&Bond以及实验粘结剂中可以清楚地识别出银渗入的纤维间空间，而在两步法自酸蚀粘结剂Clearfil SE Bond和Clearfil Protect Bond中，这些空间较薄且只是偶尔观察到。表现出从完全脱矿牙本质到矿化牙本质更突然转变的更具侵蚀性的一步法和两步法粘结剂，在混合层下方没有这些银渗入的纤维间空间。在一些自酸蚀粘结剂中观察到的树脂渗入不完全，可能是由于酸性单体对混合层底部的蚀刻潜力降低，或者存在酸性但不可聚合的水解粘结剂成分，从而为这些自酸蚀粘结剂形成的粘结物降解创造了潜在位点。
