Comparison of methods to enumerate bacteria in dental unit water lines

Millipore HPC samplers are simple, self-contained test devices that can be used by personnel in dental offices who do not have microbiologic training to easily and economically monitor dental unit water quality without labora tory support. This study evaluated the correlation of HPC samplers to R2A a gar for enumerating planktonic bacteria in dental unit treatment water. Eig ht different dental units were sampled. Five replicates were performed for each media at each dilution. The Pearson correlation coefficient between th e R2A agar and HPC sampler is 0.89. These data suggest HPC samplers correla te with conventional laboratory-based R2A culture techniques for determinin g dental unit water line contamination.