This is the first study in Jordan to determine the degree of bacterial contamination of water outlets from high-speed drill and air/water syringe waterlines in dental clinics. Total heterotrophic bacterial counts (HPC), in addition to Pseudomonas aeruginosa, and Legionella pneuomophila as opportunistic pathogens were investigated in the source water, high-speed drill and air/water syringe waterlines. Heterotrophic bacterial counts (HPCs) exceeded 500 CFU/ml in 26% of the water sources supplying the units. Pseudomonas aeruginosa was detected in 12% of the source water sample supplying the...