The SARS‐1, 2009 H1N1 MERS, Ebola and Zika outbreaks were instrumental in drawing attention to medical aerosols as sources of infection to health‐care personnel. Two broad categories of AGMP have been documented in the literature: those that induce the patient to express the contents of the lower respiratory tract by stimulating cough reflex (sputum induction), and those that mechanically disrupt the contents of the respiratory tract. The latter procedures typically include intubation/extubation, cardiopulmonary resuscitation, bronchoscopy, noninvasive ventilation, tracheotomy, airway suctioning, manual ventilation, and administering oxygen or nebulized medication. All these procedures are conducted on patients who are typically experiencing active disease, and therefore, the aerosols and droplets generated from sites with active pathogen colonization could potentially contain high numbers of respiratory pathogens. However, even though MAGP have been the subject of at least 400 different studies, questions still remain regarding the amount of aerosols generated, the size and concentration of medically aerosolized particles, and whether such aerosols could transmit viable pathogens to HCP or to other patients. For instance, the review by Davies et al. and by O'Neil et al. suggests that although the potential for aerosol production exists with AGMP, there is little evidence that these procedures actually do create aerosols.

During dental procedures, the “wet environment” created by saliva and water coolant combined with high‐speed instrumentation generates a large spray which disperses in many forms as dictated by the physics of aerosol creation (see section on characteristics of aerosols, above). Thus, the spray can initially take the form of spatter, droplets, droplet‐nuclei, a true aerosol, or some combination thereof; and continue to evolve based on room temperature, humidity, airflow dynamics, electrostatic forces etc. The term “dental aerosol”, therefore, is somewhat of a misnomer, because it does not encompass the various airborne particles that can be created during an AGDP. To avoid confusion, we will use the word spray unless the study specifically measured aerosols.

There are four main sources of dental sprays: air‐water syringes, ultrasonic instruments, high‐speed turbines, and lasers. There is no literature on sprays from air‐water syringes, so we will examine the evidence from the rest of instruments below.