The relationship between oral hygiene and oral colonization with Candida species in healthy adult subjects*

Abstract

Poor oral hygiene has been frequently suggested as a predisposing factor for oral candidal colonization, but the convincing evidence is lacking. To assess and compare oral candidal colonization, both quantitatively and qualitatively, in groups of healthy dentate subjects with different levels of oral hygiene as determined by the plaque index (PI) and gingival index (GI) scores. The concentrated oral rinse technique was used to isolate Candida species from 149 healthy dentate subjects. Candida species were cultured on Sabouraud's dextrose agar plates and identified by germ-tube test and the automated Vitek(R) system biochemical yeast card. According to the PI and GI scores, subjects were divided into different groups of oral hygiene level. Candida species were isolated from 86 (57.7%) subjects. The prevalence of candidal carriage increased significantly as a function of age (P = 0.023), but was comparable between males and females (58.7% and 56.7% respectively; P = 0.87). Oral candidal carriage rate and density were not affected by the levels of dental plaque or gingival condition. The prevalence of oral candididal carriage was significantly higher in the subjects who were not using dental floss compared with those who were using dental floss (P = 0.032). Oral hygiene status, as determined by the PI and the GI scores per se, does not affect oral candidal colonization in healthy dentate subjects.