SARS-Cov-19, the virus that causes COVID-19, is transmitted via aerosols, droplets and contact. As such, the COVID-19 pandemic has placed a renewed emphasis on the importance of infection control in the dental environment, where aerosol generation is an unavoidable consequence of numerous procedures.
As we focus on ways to minimize the risk of airborne transmission in the dental office, we discuss the value of pre-procedural mouth rinses in reducing viral and bacterial loads in aerosols.
Many dental procedures are known to generate aerosols and spatter. Aerosols, in particular, are generated during use of ultrasonic scalers, high-speed handpieces and three-in-one air/water syringes. Heavier spatter particles settle quickly near the generation site, while smaller aerosolized particles remain airborne for extended periods of time (up to several hours) and travel further.
Measuring 50 micrometers (microns) or less in size, dental aerosols contain microorganisms present in saliva and the oral cavity. In addition to common oral bacteria, these aerosols may contain other microorganisms including:
- Legionella pneumophilia, the bacteria that causes Legionnaire’s disease.
- The herpes simplex virus.
- Mycobacterium tuberculosis
- The influenza virus
Aerosols are a potential mode of transmission for microorganisms in the dental operatory, and remain in the air long enough to be present when team members and other patients are potentially present. During the COVID-19 pandemic the dental operatory is considered a high-risk environment due to SARS-CoV-2.
Pre-procedural rinsing and aerosols
The CDC noted in 2003 in the Guidelines for Infection Control in Dental Health-Care Settings — 2003 that pre-procedural rinsing with an antimicrobial product can reduce the microbial load in aerosols and spatter. A 2019 systematic review published in the Journal of the American Dental Association (JADA) concluded that pre-procedural rinsing prior to a dental procedure reduces the bacterial load in aerosols originating from the oral cavity, which may reduce bacterial disease transmission.
Pre-procedural rinsing is an off-label use of mouthrinses. The active ingredient in the product may be one of the following common antimicrobial agents:
- Chlorhexidine gluconate, as found in Colgate Periogard and Colgate Savacol.
- Cetylpyridinium chloride, as found in Colgate Plax and Colgate Total.
- Hydrogen peroxide, as found in Colgate Peroxyl.
- Essential oils.
The CDC guidance for dental settings states that pre-procedural rinsing may reduce microbial levels in treatment-generated aerosols. It is worth noting that the CDC also states that there is no published evidence supporting the efficacy of pre-procedural mouthrinse in reducing SARS-CoV-2 viral loads or transmission specifically. An article published in the International Journal of Oral Science recommended that, because the virus is vulnerable to oxidation, pre-procedural mouth rinse containing 1% hydrogen peroxide or 0.2% povidone be used. Given that these are both oxidative agents, this is indeed plausible.