Hebling J, Pashley D H, Tjäderhane L, Tay F R
Department of Orthodontics and Pediatric Dentistry, Araraquara Dental School, University of São Paulo State,São Paulo, Brazil.
J Dent Res. 2005 Aug;84(8):741-6. doi: 10.1177/154405910508400811.
The recent paradigm that endogenous collagenolytic and gelatinolytic activities derived from acid-etched dentin result in degradation of hybrid layers requires in vivo validation. This study tested the null hypothesis that there is no difference between the degradation of dentin bonded with an etch-and-rinse adhesive and that in conjunction with chlorhexidine, an MMP inhibitor, applied after phosphoric-acid-etching. Contralateral pairs of bonded Class I restorations in primary molars of clinical subjects were retrieved after a six-month period of intra-oral functioning and processed for transmission electron microscopy. Hybrid layers from the chlorhexidine-treated teeth exhibited normal structural integrity of the collagen network. Conversely, abnormal hybrid layers were seen in the control teeth, with progressive disintegration of the fibrillar network, to the extent that it was beyond detection by collagen staining. Self-destruction of collagen matrices occurs rapidly in resin-infiltrated dentin in vivo and may be arrested with the use of chlorhexidine as an MMP inhibitor.
近期的一种观点认为，酸蚀牙本质产生的内源性胶原溶解和明胶溶解活性会导致混合层降解，这需要进行体内验证。本研究检验了一个零假设，即使用酸蚀冲洗粘合剂粘结的牙本质与磷酸酸蚀后使用MMP抑制剂氯己定联合处理的牙本质在降解方面没有差异。在临床受试者的第一恒磨牙中，对粘结的I类修复体的对侧牙进行为期六个月的口腔内功能测试后取出，并进行透射电子显微镜检查。经氯己定处理的牙齿的混合层显示出胶原网络的正常结构完整性。相反，在对照牙齿中观察到异常的混合层，纤维状网络逐渐解体，以至于无法通过胶原染色检测到。胶原基质在体内树脂浸润的牙本质中会迅速发生自毁，使用氯己定作为MMP抑制剂可能会阻止这种情况发生。
