How can aerosols be reduced during air polishing and ultrasonic scaling?

Based on the indexed literature, several complementary strategies can reduce aerosol and droplet contamination during ultrasonic scaling (evidence on air polishing specifically is limited in these passages).

For evacuation, combining high-volume evacuation (HVE) with an intraoral suction device produces significant reductions in colony-forming units (CFUs) compared with either device used alone during oral prophylaxis procedures ^[1]. Extraoral suction (EOS) devices positioned close to the patient's mouth are also effective, with one chairside EOS system achieving statistically significant CFU reductions at the patient's chest area where aerosol concentration is highest ^[2]. A separate RCT found that an EOS performed comparably to HVE and was superior to a saliva ejector alone at the operator's and patient's chest surfaces ^[3]. Positioning an extraoral high-volume evacuator (eHVE) within 10 cm of the mouth renders bacterial contamination from aerosols negligible; moving it to 20 cm allows more detectable contamination to reach the dentist's and patient's chest areas ^[4].

Preprocedural mouth rinsing adds a further layer of protection: povidone-iodine 0.5% reduced viable bacterial counts by 31–38% and essential oil rinse by 22–33% compared with water, particularly useful when the evacuator cannot be held very close to the mouth ^[4]. Meta-analysis confirms that ultrasonic scalers significantly increase airborne bacteria up to 2 m away, and that LVE, HVE, or combinations of devices can all reduce this contamination, though no single suction type showed a statistically significant advantage over another in that meta-analysis ^[5]. In summary, the most evidence-supported approach is combining close-proximity extraoral or intraoral evacuation with preprocedural antiseptic rinsing ^[4][1][3].