the effect of thymus vulgaris essential oil and chlorhexidine on candida albicans accumulated on removable orthodontic appliance: a clinical trial

Statement of the problem: orthodontic removable appliances can facilitate the accumulation of certain microorganisms and microbial plaque on tooth surfaces and appliance components. since long-term use of chemical agents is not recommended, an alternative option would be medicinal plants for disinfection of the oral cavity. purpose: the aim of this study was to assess the efficacy of thymus vulgaris (t. vulgaris) essential oil to decrease the count of candida albicans (c. albicans) accumulated on removal orthodontic appliances materials and method: in this 2-arm parallel controlled clinical trial, forty-four patients whose removable orthodontic appliances were contaminated with c. albicans were randomly divided into two groups by electronic random sampling. in the first group, t. vulgaris essential oil spray and in the second group, 0.2% chlorhexidine (chx) spray was applied to the appliances. thereafter, the c. albicans colony count was measured at baseline (t0) and at 2 (t1) and 5 (t2) days after the intervention. microbial samples were collected by a sterile swab from 3 spots on the internal surface of orthodontic appliances. the friedman test was used for within-group comparisons and the mann whitney test was employed to compare the efficacy of t. vulgaris essential oil with chx. results: the results of this study revealed that continuous use of 2%t. vulgaris essential oil or 0.2% chx significantly decreased the colony count of c. albicans on removable orthodontic appliances; howevere, no significant difference was noted in the efficacy of 2% t. vulgaris essential oil and 0.2% chx in decreasing the c. albicans colony count. conclusion: t. vulgaris essential oil and chx have favorable antimicrobial activity against c. albicans. moreover, 2% t. vulgaris essential oil can be considered as an alternative to 0.2% chx to eliminate fungal contamination of orthodontic appliances.