Abstract ObjectivesThis study aimed to develop a risk prediction scale for COVID-19, based on an analysis of the dynamic behavior of aerosols generated during dental procedures.Materials and methodsThe dispersion of aerosols during dental procedures performed in six dental clinics was evaluated using standardized photographs. The digital images were processed to analyze the stained area and the dimensions of the drops. A logistic regression model was built with the following variables: ventilation, the distance from the mouth, the instrument used, the area in the mouth to be treated, and the location within the perimeter area.ResultsThe variables that were associated with a higher risk of exposure in the prediction scale were a distance of less than 78 cm; improper ventilation; the use of a high-speed handpiece; the location of the patient, operator, and assistant; and, to a lesser degree, the intervention of the anterior region of the mouth. The sizes of a large percentage of aerosolized particles ranged from 1 to 5 µm. The maximum settlement range from the mouth of the phantom head was 320 cm, with a high-risk cut-off distance of 78 cm.ConclusionsContamination by disseminating aerosols represents a significant risk for the dental team. Thus, it is advisable to improve ventilation, use extreme biosecurity measures and all the cleaning and disinfection measures.Clinical relevanceThe need to implement new clinical care strategies was evident. The scale is useful for predicting the risk of exposure to the contagion of COVID-19 in the dental office.