Antifungal Effect of Zataria multiflora Essence on Experimentally Contaminated Acryl Resin Plates With Candida albicans

BACKGROUND Adherence and colonization of Candida species particularly C. albicans on denture surfaces, forms a microbial biofilm, which may result denture stomatitis in complete denture users. OBJECTIVES The purpose of the present study was to evaluate the antifungal effect Zataria multiflora essence in removing of Candida albicans biofilms on experimentally contaminated resin acryl plates. MATERIALS AND METHODS In the present experimental study, 160 resin acrylic plates (10 × 10 × 1 mm) were contaminated by immersion in 1 × 10(3) C. albicans suspension for 24 hours to prepare experimental Candida biofilms. The total number of Candida cells, which adhered to 20 randomly selected acryl resin plates was determined as the Candia load before cleaning. The remaining 140 plates were divided to seven groups of 20 and immersed in five concentrations of Zataria multiflora essence from 50 to 3.125 mg/mL as test, 100000 IU nystatin as the positive and sterile physiologic serum as the negative control. The remaining Candida cells on each acryl plate were also enumerated and data were analyzed using the SPSS 16 software with Kruskal-Wallis and Wilcoxon tests. RESULTS Zataria essence at concentrations of 50 and 25 mg/mL removed 100% of attached Candida cells similar to nystatine (MFC), while weaker Zataria essence solutions cleaned 88%, 60.5% and 44.7% of attached Candida cells. Kruskal-wallis test showed a statistically significant difference between all test groups (P = 0.0001). In this study 12.5 mg/mL concentration of Zataria multiflora was considered as the minimum inhibitory concentration (MIC90). CONCLUSIONS Zataria essence, at concentrations of 50 and 25 mg/mL, effectively removed Candida cells that had adhered to the denture surface, similar to the level of removal observed for 100000 IU nystatin.