OBJECTIVE To investigate the effectiveness of contamination control measures for oral microbial aerosols, this study tested and analyzed the role of air sterilizers, as well as air conditionings, dental suction systems and clinic water containing disinfection factors, in air purification in the oral spattering treatment environment.

METHODS A 10⁸ CFU/ml of Staphylococcus albicans bacterial suspension was selected and released slowly at a rate of 0.5 ml/min onto resin teeth of imitation head mold to simulate the oral saliva environment. A high-speed dental handpiece was used to prepare the lower anterior teeth for 20 min on the resin teeth. The study grouped the aerosol purification measures into separate and combined use, and the air was continuously sampled by an Anderson six-stage impact sampler at a rate of 28.3 L/min at a distance of 1.6 m from the spattering source for 5 min, at the 15th minute of the spattering operation and 15 minutes after stopping the spattering operation. The total number of colonies was calculated. The effect of each group was evaluated by the standard of 500 CFU/m³ for qualification.

RESULTS During the spattering operations, air sterilizers combined with the dental suction systems or clinic water containing disinfection factors could effectively reduce the air bacterial content (P < 0.05), the airborne bacteria could be reduced over 70%. There was no statistically significant difference of airborne bacteria between the natural ventilation group and the control group during and after the spattering operation. The other experimental groups showed a significant decrease in airborne bacteria concentrations after the spattering operation (P < 0.05), especially when dental suction systems or the combined application of clinic water containing disinfection factors with air sterilizers, the airborne bacteria could be reduced over 90%. The air conditioner did not have remarkable interference on the parification efficiency of the cabinet-type air sterilizer.

CONCLUSIONS Oral spattering operations can cause extensive microbial contamination in the treatment environment. Natural ventilation shows no significant contamination control effect in a short term. Dental suction system and clinic water containing disinfection factors play an important role in air pollution control as source control measures. Air sterilizers can play a continuous significant role in air purification.