An in-vitro evaluation of microwave irradiation and denture cleansers on disinfection and destaining of denture base resin

PurposeDenture cleansing tablets have been used effectively against stains and Candida when soaked for longer time yet complete sterilization against broad range of bacteria is questionable. Microwave sterilization has been shown effective against bacteria and fungus both but not against stains. Our study aims to comparatively evaluate the efficacy of microwave irradiation and denture cleanser on the disinfection and destaining of stained denture.Materials and methodsNinety-nine acrylic sheets were stained with Acacia catechu and lime and sterilized in UV chamber. Three samples served as negative control and remaining 96 samples were divided in groups A, B, C and D according to contaminating microorganism; three bacteria and one fungus. According to time of irradiation, groups were subdivided into subgroups-1 (2 min), 2(4 min), 3(6 min) and 4 (denture cleanser for 8 h). Microwave irradiation was done either in presence of water or denture cleansing solution. Following procedure samples were scored for staining and then inoculated for 24 h. Then after broth were checked for OD. One sample from each subgroup was inoculated for cfu count.ResultsEffective disinfection for all stained samples achieved with microwave for 6 min in presence of water or denture cleansing solution. Denture cleanser for 8 h was more effective for Candida albicans. 100% stain removal was found with irradiation for 6 min in presence of denture cleanser.Conclusion6 min microwave irradiation in presence of denture cleansing solution could achieve complete sterilization even for spore and membrane forming bacteria. Simultaneously it completely destained all the samples.