Adental aerosol is anaerosol that is produced fromdental instrument,dental handpieces, three-way syringes, and other high-speed instruments. These aerosols may remain suspended in the clinical environment.[1] Dental aerosols can pose risks to theclinician, staff, and other patients. The heavierparticles (e.g., >50 μm) contained within the aerosols are likely to remain suspended in the air for relatively short period and settle quickly onto surfaces, however, the lighterparticles may remain suspended for longer periods and may travel some distance from the source.[2] These smaller particles are capable of becoming deposited in thelungs when inhaled and provide a route ofdiseases transmission.[3] Different dental instruments produce varying quantities of aerosol, and therefore are likely to pose differing risks of dispersing microbes from the mouth. Air turbine dental handpieces generally produce more aerosol, with electric micromotor handpieces producing less, although this depends on the configuration of water coolant used by the handpiece.[4][5]
Spatter and aerosols flushing out of dental hand piece
These dental aerosols arebioaerosols which may be contaminated withbacteria,fungi, andviruses from the oral cavity,skin, and thewater used in dental units.[6] Dental aerosols also havemicro-particles from dental burs, and silica particles which are one of the components ofdental filling materials likedental composite.[7] Depending upon the procedure and site, the aerosol composition may change from patient to patient. Apart frommicroorganisms, these aerosols may consist of particles fromsaliva, gingival crevicular fluid,blood,dental plaque,calculus, tooth debris, oronasal secretions, oil from dental handpieces, andmicro-particles from grinding of theteeth and dental materials.[8] They may also consist ofabrasive particles that are expelled duringair abrasion andpolishing methods.[3]
Dental aerosols contain a wide range of particles with the majority being less than 50 μm. The smaller particles with size between 0.5 and 10 μm are more likely to be inhaled and have the potential to transmitinfection.[3] Smaller particles are likely to remain suspended for longer periods of time, and may travel further from the source. Settling time of particles is described byStokes' law in part as a function of their aerodynamic diameter.
Thewater used in the dental units may be contaminated withLegionella, and the aerosols produced by dental handpieces may contribute to the spread of theLegionella in the environment; there is therefore a risk ofinhalation by thedentist, staff and patients.[9] The dental unit water lines (DUWLs) may also becontaminated with otherbacteria likeMycobacterium spp andPseudomonas aeruginosa.[10] Infection fromLegionella species causes infections likeLegionellosis and severalpneumonia like diseases.[11] However, still there is no strong evidence that suggests the dentists are at greater occupational risk fromLegionella.[9] Transmission oftuberculosis also occurs from thecough producing procedures on the patients withtuberculosis that involve production of aerosols.[12]Mycobacterium tuberculosis is transmitted in the form of droplet nuclei which are smaller than 5 μm which stay suspended in the environment for longer duration. The development of active tuberculosis in Dental Health Care Workers (DHCWs) is less likely than the rest of the other Health Care Workers (HCWs). There are lacking evidences to prove the active tuberculosis development resulting from this transmission in Dental health care Workers (DHCWs).[13]
Dentists have previously been described as one of the top of the working groups with high risk of exposure to SARS-CoV-2. Due to the close proximity of the dental health care workers to the patients, dental procedures involving aerosol production is not advisable in patients who tested positive for COVID-19 except for emergency dental treatment.[17] On 16 March 2020, theAmerican Dental Association (ADA) has advised dentists to postpone all elective procedures.[18]ADA also developed guidance specific to address dental services during theCOVID-19 pandemic.[19]
Elements like calcium, aluminium, silica and phosphorus can also be found in the dental aerosols produced during the procedures like debonding of orthodontic appliances.[20] These particles may range from 2 to 30 μm in diameter and there are chances of inhaling them.[21]
A number of methods have been proposed, and are widely used, to control dental aerosols and reduce risk of disease transmission. For example, dental aerosols can be controlled or reduced using dental suction,[22] rubber dam,[5] alternative handpieces,[2] and local exhaust ventilation (extra-oral suction).[23]
^King TB, Muzzin KB, Berry CW, Anders LM (January 1997). "The effectiveness of an aerosol reduction device for ultrasonic scalers".Journal of Periodontology.68 (1):45–9.doi:10.1902/jop.1997.68.1.45.PMID9029451.
^Petti S (June 2016). "Tuberculosis: Occupational risk among dental healthcare workers and risk for infection among dental patients. A meta-narrative review".Journal of Dentistry.49:1–8.doi:10.1016/j.jdent.2016.04.003.PMID27106547.
^Day CJ, Price R, Sandy JR, Ireland AJ (January 2008). "Inhalation of aerosols produced during the removal of fixed orthodontic appliances: a comparison of 4 enamel cleanup methods".American Journal of Orthodontics and Dentofacial Orthopedics.133 (1):11–7.doi:10.1016/j.ajodo.2006.01.049.PMID18174065.
^Ireland AJ, Moreno T, Price R (December 2003). "Airborne particles produced during enamel cleanup after removal of orthodontic appliances".American Journal of Orthodontics and Dentofacial Orthopedics.124 (6):683–6.doi:10.1016/s0889-5406(03)00623-1.PMID14666082.
