The Effect of Adding Thymus Vulgaris and Cinnamomum Verum Essential Oils in Self- Cured Acrylic Blocks on Adhesion of Candida Albicans

Oral candidiasis is the most common opportunistic infection of the oral mucosa with Candida spp. Candida species form a biofilm in patients who need orthodontics with removable plaque, and this structure can lead to Candidemia. It is important to find effective plant compounds, which have fewerside effects and are natural, to prevent biofilm formation. The aim of the present study was to determine the effect of adding Thymus vulgaris and Cinnamomum verum essential oils to self- cure acrylic blocks on Candida albicans colonization.

In this experimental study, the antifungal activity of essential oils of Thymus vulgaris, Cinnamomum verum and nystatin against of Candida albicans ATCC10231 was evaluated in order to determine MIC according to CLSI-M27S4 guidelines. Powder and monomer were poured into tablet molds to make self-cure acrylic plaques. A total of 144 self- cure acrylic plaques were divided into 24 groups of 6 in petri dish. Three groups contained powder and monomer, three groups contained nystatin drug, and 18 groups contained different concentrations of essential oils of Thymus vulgaris and Cinnamomum verum. Then, the samples were incubated in artificial saliva enriched, with Candida albicans at 37°C and the effects of essential oils of Thymus vulgaris and Cinnamomum verum on the binding of Candida albicans were reported by the cfu/ml count method. Statistical analysis of data was done using Stata-15 software. ANOVA and Tukey's test were used to confirm the results.

The evaluating the sensitivity of Candida albicans ATCC10231 to essential oils of Thymus vulgaris, Cinnamomum verum and Nystatin were obtained as MIC= 120µg/ml, MIC= 340µg/ml and MIC= 1µg/ml, respectively. The attachment of yeast cells to self- cure acrylic blocks for Cinnamomum verum essential oil was significant in MIC= 340 µg/ml (p= 0.02), MIC= 680 µg/ml (p= 0.01) and nystatin 1 µg/ml (p= 0.00) compared to the negative control group. However, this amount was not statistically significant for Thymus vulgaris essential oil        (p= 0.14).

Adding essential oil of Cinnamomum verum to acrylic resin prosthesis can be effective in controlling the proliferation of Candida albicans on the surface of the prosthesis. However, its effects on the physical properties of acrylic resin dentures need further studies.