Grytten J, Tollefsen T, Afseth J
Department of Microbiology, Dental Faculty, University of Oslo, Norway.
Acta Odontol Scand. 1987 Dec;45(6):429-33. doi: 10.3109/00016358709096368.
Zn++ in combination with hexetidine exerts a synergistic plaque inhibition. Studies in our laboratory on the mechanism of this effect suggested that Cu++ and hexetidine may have a similar combination effect. This hypothesis was tested in vivo on a human test panel in a double-blind crossover study. The amount of Cu++ retained by plaque bacteria in vitro was also evaluated. Seven volunteers rinsed with the solutions for 1 min twice daily for 5 days. The test solutions were H2O, 1.0 mM CuSO4, 2.0 mM hexetidine, and the last two in combination. During the test period no oral hygiene was allowed, and sucrose-containing chewing gum was used to enhance plaque formation. The plaque index scores after rinsing with the combination were significantly (p less than 0.05) lower than those of the other solutions. The effect of hexetidine on Cu++ retention in plaque bacteria was evaluated in plaque samples (n = 3) grown anaerobically overnight in PPLO medium. The bacteria were washed five times, digested in concentrated HNO3, and Cu++ determined by atomic absorption. The presence of hexetidine resulted in a significantly greater amount of Cu++ retained by bacteria at all CuSO4 concentrations. It is suggested that the nonpolar nature of the hexetidine molecule enables Cu++ bound to hexetidine to pass into the bacterial cell. Within the cell, Cu++ can interfere with bacterial metabolism, giving a reduction in plaque growth.
锌离子（Zn++）与己脒定联合使用时具有协同抑制牙菌斑的作用。我们实验室对这种作用机制的研究表明，铜离子（Cu++）和己脒定可能有类似的联合作用。在一项双盲交叉研究中，对一组人类受试者进行了体内试验以验证这一假设。同时还评估了体外牙菌斑细菌对铜离子的摄取量。7名志愿者每天用溶液漱口2次，每次1分钟，持续5天。测试溶液分别为水、1.0 mM硫酸铜、2.0 mM己脒定以及后两者的混合溶液。在测试期间，不允许进行口腔卫生清洁，并使用含蔗糖的口香糖来促进牙菌斑形成。用混合溶液漱口后的牙菌斑指数得分显著低于其他溶液（p<0.05）。在PPLO培养基中厌氧培养过夜的牙菌斑样本（n = 3）中评估了己脒定对牙菌斑细菌摄取铜离子的影响。细菌洗涤5次后，用浓硝酸消化，通过原子吸收法测定铜离子含量。在所有硫酸铜浓度下，己脒定的存在都会使细菌摄取的铜离子量显著增加。这表明己脒定分子的非极性性质使得与己脒定结合的铜离子能够进入细菌细胞。在细胞内，铜离子会干扰细菌代谢，从而减少牙菌斑的生长。
