Pumice slurry as a crossinfection hazard in nonclinical (teaching) dental technology laboratories.

This research sought to compare the microbiological status of pumice slurry in clinical and nonclinical dental laboratories. Samples were inoculated onto selective and nonselective media. Resultant colonies were counted and identified to genus or species level. In the nonclinical laboratory, counts were constant at approximately 10(7) to 10(8) cfu/g. Pseudomonads, staphylococci and Bacillus spp comprised the major pumice contaminants in both laboratories. It was concluded that nonclinical laboratories are not immune from the presence of potentially pathogenic microorganisms in pumice slurry. Disinfection reduces contamination by oral microorganisms.