Nordbö H, Eriksen H M, Rölla G, Attramadal A, Solheim H
Scand J Dent Res. 1982 Apr;90(2):117-23. doi: 10.1111/j.1600-0722.1982.tb01533.x.
Extrinsic discoloration of teeth following a large consumption of tannin-containing beverages or a prolonged use of chlorhexidine mouthrinses is a well known observation. Tannins as well as chlorhexidine are denaturing agents. Based on preliminary studies revealing the presence of iron in chlorhexidine discolored pellicle material, the ability of iron to stain the integument after pretreatment with the two denaturants was studied in a human model. The denaturing effect of an acidic environment was also included. Enamel slabs fixed to acrylic appliances were carried in the oral cavity and alternately exposed to the test solutions in different sequences in vitro. Pretreatment with chlorhexidine or tannic acid led to marked discoloration upon iron application during 5-d tests, whereas the compounds individually had no such effect. A large content of the metal was found in the stained material. Stannous fluoride appeared to reduce the formation of the pigments, and strong oxidation completely bleached the established color. Possible mechanisms underlying the phenomena observed are discussed.
大量饮用含单宁的饮料或长期使用氯己定漱口水后牙齿出现外部变色是一个众所周知的现象。单宁和氯己定都是变性剂。基于初步研究揭示氯己定变色的牙菌斑物质中存在铁，在人体模型中研究了铁在用这两种变性剂预处理后对体表染色的能力。还包括酸性环境的变性作用。固定在丙烯酸装置上的牙釉质板被置于口腔中，并在体外以不同顺序交替暴露于测试溶液中。在5天的测试中，用氯己定或单宁酸预处理后再施加铁会导致明显变色，而这些化合物单独使用时没有这种效果。在染色物质中发现大量金属。氟化亚锡似乎能减少色素的形成，强烈氧化能完全漂白已形成的颜色。文中讨论了观察到的这些现象背后可能的机制。
