Evaluation and Comparison of the Effectiveness of Physical Methods of Disinfection on Heat-Polymerized Polymethyl Methacrylate – An In-vitro Study

Introduction: The common relationship of Candida and the ample proof that acrylic resin dentures are related to denture stomatitis in the oral cavity, which can range from simple mucosal lesions to a fatal systemic form. The current study aims to assess and compare the efficacy of microwave irradiation and UV radiation in the disinfection of Candida albicans infection in heat-polymerized polymethyl methacrylate.

Materials and Methods: A total of 90 specimens were prepared with heat-polymerized acrylic resin, out of which 30 were used for Microwave irradiation, and 30 were used for UV irradiation, and 30 were used for positive control. There were three groups: Group A (Positive Control group); Group B (Microwave irradiation); Group C (UV radiation). After preparing the samples they were chemically sterilized, then infected with C. Albicans, and again Group B is disinfected with Microwave irradiation, Group C is disinfected by UV light and Group A is kept as Positive control without disinfection. Turbidity was measured for each group after re-infection of every specimen in CFU/ml.

Results: In the present study, the CFU/ml of Candida albicans in the control group was 2.97x107±0.6 x 107 (P= .000), for microwave irradiation, the mean value was 5.3±11.1 (P= .000), and for UV radiation, the mean value was 19.3±22.9 (P= .003).

Conclusion: According to the results of the current study, microwave irradiation (6 minutes at 650W) is more effective than UV radiation (10 minutes each side at 254nm wavelength) of Candida albicans infection on the heat-polymerized acrylic resin in laboratory conditions.