comparison between spray of 0.525% sodium hypochlorite and 1% virkon in disinfectation of the type III dental stone casts contaminated with microbial strains (candida albicans, Basillus subtilis)

Abstract

There is a close contact between dental casts and impression materials as well as other items potentially contaminated by saliva and blood from a patientEs mouth. Consequently dental casts are one of the important items that lead to cross-contamination. To interrupt the cross-contamination cycle, several methods have been applied so far, more dominantly chemical disinfection procedures either by immersion or surface spray methods. Virkon is a unique powder product for the safe and rapid disinfection of surfaces and equipment in a wide variety of situations. It is dissolved in water for use, providing a safe working solution with a faint lemon odour. The objective of the present study is to evaluate the antimicrobial, fungocidal and sporocidal activities of virkon 1% and hypochlorite 0.525% on dental casts made of type III dental stone using spraying method . Bacillus subtillis and ?Candida albicans as test organisms were used to contaminate the dental casts intentionally. Material and methods Different concentrations of virkon and hypochlorite were prepared, using distilled water and then were sprayed on the surface of the dental casts contaminated with Bacillus subtilis and Candida albicans.Pour plate method was used to evaluate the antimicrobial afficacy of each solution. Microbicidal effect (ME) was calculated according to log of control colony count values minus. log of remaining colony count after antimicrobial procedure. Results: Virkon showed acceptable activity against Candida albicans in the concentrations ( 3%,2%,1%,0.5%,0.25,0%,0.125%) as well as contact times (2 & 5 minutes) used in this study, and can be considered as an effective fungicidal agent. However the results pertaining to the antimicrobial test of Virkon against sporogenes bacterium i.e. Bacillus subtilis were not satisfying in 1% concentration (used concentration) and even higher using our test procedure. However it could disinfect (ME=5.02) the stone cast. Conclusion: According to our results Virkon can be considered as a low level disinfectant and based on its low toxicity and good invironmental compatibility, may be advised as an antimicrobial agent for dental stone casts as non-critical items.