Klont B, ten Cate J M
Department of Cariology and Endodontology, Academic Center for Dentistry Amsterdam (ACTA), The Netherlands.
Caries Res. 1991;25(1):46-50. doi: 10.1159/000261341.
The susceptibility of the organic matrix from permanent bovine incisor roots to proteolytic breakdown after in vitro lesion formation was investigated. Root surfaces were exposed to 0.1 M acetic acid, pH 4.0, to produce erosive lesions or to 0.1 M lactic acid, 0.2 mM methane hydroxy diphosphonate, pH 5.0, to produce subsurface lesions. After demineralization, the roots were treated with a bacterial collagenase. The quantity of enzyme-degradable collagen in the root tissue was found to be proportional to the calcium released during demineralization, until a plateau value was reached at calcium concentrations in solution of 3.3 mM at pH 4.0 and 2.7 mM at pH 5.0. The degradability of collagen was found to be substantially less in subsurface lesions than in erosive lesions. The presence of cementum-free areas did not affect the results. These findings suggest that the mineral component of the roots is composed of several fractions which differ in their solubility properties in weak acids.
研究了体外形成病变后，恒河牛切牙根的有机基质对蛋白水解降解的敏感性。牙根表面暴露于pH 4.0的0.1 M乙酸中以产生侵蚀性病变，或暴露于pH 5.0的0.1 M乳酸、0.2 mM甲氧基二膦酸中以产生亚表面病变。脱矿后，用细菌胶原酶处理牙根。发现根组织中可被酶降解的胶原蛋白量与脱矿过程中释放的钙成正比，直到在pH 4.0时溶液中钙浓度达到3.3 mM和pH 5.0时达到2.7 mM时达到平台值。发现亚表面病变中胶原蛋白的可降解性明显低于侵蚀性病变。无牙骨质区域的存在不影响结果。这些发现表明，牙根的矿物质成分由几个部分组成，它们在弱酸中的溶解特性不同。
