Evaluation of Denture Cleansers against Candida albicans, Part II

Abstract

Candida albicans is known to cause denture stomatitis. In this study, the effects of four kinds of commercial denture cleansers (DC A, B, C and D) on C. albicans were evaluated under the various conditions. Yeast-lytic enzymes were contained only in DC A. Proteases were contained in DC A, B and C, and alkaline-oxidants were contained in DC B, C and D.
Candida-lytic activity was demonstrated only in DC A from the results of the reduction of optical density of yeast suspension, the microscopical observation and the degradation of β-1, 3-glucan.
Strong fungicidal effects were found in DC B and C. The fungicidal effect in DC D was slightly lower than that in DC B and C, and the effect in DC A, which contained no oxidants, was the lowest. However, it was found that a small amount of Candida cells was alive, even in the solution of DC B, C and A when the residual cleansers were removed and then inoculated on the culture plate.
Resin plates adhering Candida cells were soaked in the cleansers, and then the remaining cells were counted under the microscope. The removal of the adhering cells by DC A, B and C were significantly greater than that by the control. But DC D did not show any significant differences from the control and the other cleansers.
DC A exhibited the highest protease activity at pH 7. At the own pH of cleansers, however, DC C exhibited higher activity than DC A. The protease activity in DC B was lower than that in DC A and C. DC D exhibited no protease activity, but it generated the largest quantity of hydrogen peroxide. No hydrogen peroxide was generated from DC A.