ABSTRACT
Water delivered through dental unit waterline system(DUWS) is often reported contaminated with microbesdislodged from biofilm that forms within the tubingof a dental chair unit (DCU). ADM: The study aimedat evaluating the sanitary level of DCU water froma teaching dental clinic. Materials: The presence ofpathogenic bacteria which include total coliforms, faecalcoliforms, E. coli, faecal streptococci and P. aeruginosawere determined using conventional microbiologicalmethods while PCR technique was used to identify othermicrobial contaminants. Result: pH of DCU water wasfound slightly acidic at pH 5.4-5.5 and the temperaturewas 23°C. Pathogenic contaminants were absent butthe DCU water was highly loaded with Sphingomonasrhizogenes (17.9%), Sphingomonas dokdonesis(79.5%), Sphingomonas mucosissima (1.1%) andMethylobacterium radiotolerans (1.5%). The high load ofmicrobes that exceeded 200 cfu/ml was of great concernas it failed to meet recommendation set by the AmericanDental Association