Detecting Legionella pneumophila in water systems: a comparison of various dental units.

The authors sampled 194 dental units over a 44-month period to detect the presence of Legionella pneumophila. They found L. pneumophila, usually in very low numbers, in 25 percent of the units over this time. However, higher counts were collected from 4 percent of the units, primarily from one model. The authors document colony counts collected from nine different models and those collected from air/water syringes vs. high-speed outlets, and they describe the effectiveness of disinfection.