Evaluation of microbiological and physical parameters of water from dental clinics in a brazilian university

Abstract

Introduction and objective: Contamination of the water used in health care units can induce adverse individual and collective consequences. The objective of this study was to evaluate the water quality in dental clinics of a dentistry program of a university in Brazil, calculating the total coliforms, thermotolerant coliforms, heterotrophic bacteria and pH. Materials and methods: In each clinic, water samples were collected for analysis at different points: external cistern, clinic faucet, dental chair tank and triple syringe. After sample collection, analysis was performed: the presence of total coliforms and thermotolerant coliforms was determined by chromogenic substrate technique, the presence or absence of Escherichia coli by fluorescence in ultraviolet light, the count of heterotrophic bacteria through the number of colonies and the determination of pH. Results: In all studied sites, the presence of total coliforms, Escherichia coli and thermotolerant coliforms was observed in at least 26% of the samples. In relation to CFU / ml, all mean values were much higher than the maximum established by legislation (500 CFU / ml). It was verified a statistically significant difference was found in the external cistern and tap when compared to the chair tank and triple syringe (p < 0.05). All pH samples were within the standards. Conclusion: The global analysis showed that 100% of the samples were inadequate, which classified the water potability as nonstandard in regard to the current Brazilian legislation.