Quantitative microbial monitoring in a dental office

The aim of this study was to evaluate the environmental pollution before an d after dental procedures (during one year) in a dental office in which a s ystem of air filtration was effective and suitable procedures of microbial controls were routinely applied for instruments and small surfaces. The air contamination was evaluated during one year by the 'plate' method (Air Mic robial Index, AMI) in each room of the dental office following a bimonthly monitoring program. Nutrient agar plates were exposed, in monitored areas f or 1 h for each control time and incubated at 37 degreesC for 2 days. The n umber of viable cells was expressed as colony forming units per plate per h our (CFU/plate/h). During the observation year, the quantitative analysis of the microbiologic al levels in the operative areas was always within acceptable values. In fa ct, a range from 4-18 CFU/plate/h was found as the mean of AMI in each cont rolled room. In particular, the aerosol pollution following dental procedur es did not significantly modify AMI values compared with AMI values recorde d before dental procedures. Data presented here demonstrate that the combined use of effective infectio n control procedures and a system of air filtration can be efficacious in r educing airborne environmental contamination in a dental office and emphasi se the use of an inexpensive method such as AMI to verify the environmental bacterial pollution.