Effectiveness of antimicrobial mouthrinses on aerosols produced by an air polisher.

PURPOSE: The purpose of this examiner-blind investigation was to study the effect of two antimicrobial mouthrinses on the quantity and potential respiratory-penetrating ability of microorganisms generated by an air-abrasive polisher.

METHODS

Forty-five adult subjects were randomly assigned to one of three groups and asked to rinse for 30 seconds with 15 ml of either a 0.12% chlorhexidine rinse, an essential oil mouthrinse, or water prior to air polishing. Prior to treatment, microbes in ambient air were collected for five minutes using an Andersen air sampler. This device simulates the human respiratory system and collects airborne microbes by means of blood agar plates stacked in a cascade impact system. Bacteria found at stages two, four, and six--representing the pharynx, bronchi, and alveoli-were collected and counted in this study. During three minutes of air-abrasive instrumentation and two minutes immediately following, airborne microbes were again collected. Agar plates removed from the sampler were incubated for 24 hours at 37 degrees C. Colony-forming units per cubic foot of air (CFUs/ft(3)) were enumerated using a Lab Line colony counter. Data were analyzed using a two-factor repeated measure ANOVA and Dunn's multiple mean comparison techniques.

RESULTS

Results showed no significant effect of prerinsing among treatment groups. An increase in CFUs/ft(3) was found at each sequential stage of the air sampler, resulting in a statistically significant within-group effect (p< or =.05). Additionally, a significant interaction was found between prerinse treatment and respiratory stage (p< or =.05) .

CONCLUSION

While the air-abrasive polisher produced significant amounts of deeply penetrating bacterial aerosol, differences in CFUs/ft(3) generated following the antimicrobial prerinsing tested are of little clinical significance.