Currently, the mitigation of aerosols and minimizing of aerosol-generating procedures within the dental office are a priority. The Centers for Disease Control (CDC) Guidance for Dental Settings (updated Dec 4, 2020) focus on administrative controls and work practices such as four-handed dentistry, high evacuation suction, and dental dams to minimize droplet splatter and aerosols. (1) But while CDC Guidelines continue to evolve during the COVID-19 pandemic, the infection control risks of aerosols and splatter in dentistry is not new topic.
An aerosol is a suspension of fine solid particles or liquid droplets in air. Aerosols created by the use of powered dental equipment, specifically high- and low-speed handpieces, ultrasonic scalers, or prophy handpieces, can contain infectious particles such as bacteria, fungi, and viruses that can pose a risk to the dental team and patient. (2) The source of potentially infectious material include the dental treatment site and dental unit water lines. (3)
Dental aerosols are defined as particles less than 50 micrometers in diameter. In a 2004 article from the Journal of the American Dental Association titled ‘Aerosols and Splatter in Dentistry’ Drs. Harrell and Moliari stated, “Particles of this size are small enough to stay airborne for an extended period before they settle on environmental surfaces or enter the respiratory tract. The smaller particles of an aerosol (0.5 to 10 μm in diameter) have the potential to penetrate and lodge in the smaller passages of the lungs and are thought to carry the greatest potential for transmitting infections.” (3)
By contrast, splatter is defined as airborne particles larger than 50 μm in diameter. Drs. Harrell and Molinari continue, “[Splatter] particles or droplets are ejected forcibly from the operating site and arc in a trajectory similar to that of a bullet until they contact a surface or fall to the floor. These particles are too large to become suspended in the air and are airborne only briefly.” (3) However some splatter droplets can still pose a risk. As the liquid within the droplets evaporates the overall size becomes small enough that the particles can now become airborne. Aerosol particles created by evaporation of splatter is called droplet nuclei.
In an article by Dr. Bentley and colleagues published in the Journal of the American Dental Association in May 1994 titled, ‘Evaluating Splatter and Aerosol Contamination During Dental Procedures’ it states, “This study demonstrates that contamination from spatter and aerosol dissemination remains a significant hazard to dental personnel when high-speed dental equipment is used.” (4) The authors recommended preventive strategies such as universal barrier precautions (masks, gloves, and eye protection), use of the rubber dam, antimicrobial rinses, preoperative tooth brushing, and high evacuation suction. In addition to the measures recommended by Dr. Bentley, the article by Drs. Harrell and Molinari article from 2004 added an additional layer of defense – a high efficiency particulate air filter (HEPA).
The simplest way to prevent aerosol generation in the dental office is to use equipment that does not generate aerosols. For dental hygienists, during the COVID-19 pandemic this has meant little to no use of ultrasonic scaling equipment, a greater reliance on hand scaling, and an increased risk of hand and wrist fatigue. In addition, it is well-known that not every patient needs coronal polishing, but if a patient presents with extrinsic stain can we really not address it?
In a recent study published in the Journal of Dental Research from December 2020 titled ‘Mechanisms of Atomization from Rotary Dental Instruments and Its Mitigation,’ the authors conclude that handpieces used at slower speed and without spray water coolant “can be used without atomization or the ejection of high-velocity droplets.”
A potential solution for the safe use of dental prophy handpieces exists when using a unit with a slower maximum speed but sufficient torque to adequately remove extrinsic stain. Based on input from dental professionals, Premier Dental Products Company recently introduced the AeroPro Cordless Prophy Handpiece System. The AeroPro system was engineered to provide clinicians with greater mobility, choice, and control; further helping to prevent symptoms of hand and wrist fatigue and to provide a better and safe polishing experience for both the dental team and patient.
Compatible with most disposable prophy angles, AeroPro allows the angle to be easily rotated 360° for improved intraoral access. From Premier’s website, AeroPro is “ergonomic and lightweight with a well-balanced design, featuring a textured grip to help reduce pinch strength and hand fatigue.” (5) It is controlled using a single button, allowing the operator to easily access the most appropriate prophy cup speed for the procedure. AeroPro’s speeds range from 500-2800 revolutions per minute while still delivering sufficient torque to deliver excellent clinical performance.
AeroPro is equipped with ChargeSMART™ Battery Technology. This innovative induction charging system powers AeroPro’s battery quickly and safely and ensures a long-lasting charge that lasts through a busy workday.
And finally, AeroPro is CDC-compliant with a convenient infection prevention protocol. The motor component is isolated by a custom-fit disposable polyurethane barrier and covered by a durable, metal outer sheath. After use the metal sheath is removed, rinsed, and autoclaved, while the motor component is disinfected.
About the author
Jason H. Goodchild, DMD, is the Director of Clinical Affairs at Premier Dental Products Company and is involved in developing innovative new products and educating dentists to improve clinical practice. He is also Associate Clinical Professor in the Department of Diagnostic Sciences at Creighton University School of Dentistry, and Adjunct Assistant Professor in the Department of Diagnostic Sciences at the Rutgers School of Dental Medicine. Dr. Goodchild maintains a private general dental practice in Havertown, PA.
References:
- Centers for Disease Control. Guidance for Dental Settings – Interim Infection Prevention and Control Guidance for Dental Settings During the Coronavirus Disease 2019 (COVID-19) Pandemic. December 4, 2020. Accessed February 21, 2021.
- Council on Dental Materials and Devices, Council on Dental Therapeutics. Infection Control in the Dental Office. J Am Dent Assoc 1978;97(4):673-677. Accessed February 21, 2021.
- Harell SK, Molinari J. Aerosols and Splatter in Dentistry. J Am Dent Assoc 2004;135:429-437. Accessed February 21, 2021.
- Bentley CD, Burkhardt NW, Crawford JJ. Evaluating Splatter and Aerosol Contamination During Dental Procedures. J Am Dent Assoc 1994;125:579-584. Accessed February 21 ,2021.
- AeroPro Cordlesss Handpiece. Premier Dental Products Company. Accessed February 21, 2021.
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