Evaluating aerosol and splatter following dental procedures: Addressing new challenges for oral health care and rehabilitation

Abstract

Background Dental procedures often produce aerosol and splatter which have the potential to transmit pathogens such as SARS‐CoV‐2. The existing literature is limited. Objective(s) To develop a robust, reliable and valid methodology to evaluate distribution and persistence of dental aerosol and splatter, including the evaluation of clinical procedures. Methods Fluorescein was introduced into the irrigation reservoirs of a high‐speed air‐turbine, ultrasonic scaler and 3‐in‐1 spray, and procedures were performed on a mannequin in triplicate. Filter papers were placed in the immediate environment. The impact of dental suction and assistant presence were also evaluated. Samples were analysed using photographic image analysis, and spectrofluorometric analysis. Descriptive statistics were calculated and Pearson’s correlation for comparison of analytic methods. Results All procedures were aerosol and splatter generating. Contamination was highest closest to the source, remaining high to 1–1.5 m. Contamination was detectable at the maximum distance measured (4 m) for high‐speed air‐turbine with maximum relative fluorescence units (RFU) being: 46,091 at 0.5 m, 3,541 at 1.0 m, and 1,695 at 4 m. There was uneven spatial distribution with highest levels of contamination opposite the operator. Very low levels of contamination (≤0.1% of original) were detected at 30 and 60 minutes post procedure. Suction reduced contamination by 67–75% at 0.5–1.5 m. Mannequin and operator were heavily contaminated. The two analytic methods showed good correlation ( r =0.930, n =244, p <0.001). Conclusion Dental procedures have potential to deposit aerosol and splatter at some distance from the source, being effectively cleared by 30 minutes in our setting.

Evaluating aerosol and splatter during orthodontic debonding: implications for the COVID-19 pandemic

“…Our group has recently developed and described a reliable and valid methodology of evaluating splatter and settled aerosol created following dental procedures using a tracer dye with digital image and spectrofluorometric analysis. 39 As part of these investigations, we have demonstrated that the use of a 3-in-1 spray (with air and water) produces significant contamination and should be regarded as an AGP, with a 30 second wash causing visual contamination up to one metre. The aim of the present study was to evaluate splatter and settled aerosol contamination following orthodontic debonding, including removal of composite using a slow speed handpiece with assistant-held dental suction.…”

“…The methods used in this study have previously been described in detail elsewhere. 39 In summary, an eight-metre diameter rig was used to support grade 1 qualitative cotton-cellulose filter papers (Whatman; Cytiva, MA, USA) spaced at 0.5 m intervals on eight, four metre rods arranged at 45-degree intervals around a dental training mannequin (Model 4820, A-dec; OR, USA). Filter papers were also placed on the forearms, chest, upper leg, and head of the operator and assistant, as well as on their masks and full-face visors.…”

“…A positive control condition – high-speed air-turbine crown preparation of the upper right central incisor with water coolant – was carried out under the same conditions as the orthodontic debonding procedure including assistant-held dental suction. This procedure was used as a positive control as it has been previously shown to produce widespread splatter and settled aerosol contamination 39 and therefore represents a “worst case” AGP for comparison.…”

Characterization and mitigation of aerosols and splatters from ultrasonic scalers

“…There is a serious deficiency in the literature regarding the risks posed by aerosols and splatter from aerosol-generating procedures (AGPs) in dental settings and the efficacy of various aerosol mitigation techniques. A number of studies have collected aerosols and splatters directly onto a collecting surface for subsequent analysis, which include fluorescent [13][14][15][16][17] or non-fluorescent [18][19][20] based chromatic indicators and microbiological methods using culture media [21][22][23][24] . These studies are limited by their inefficient collection of small size aerosols (<~50 µm) which do not provide a comprehensive characterization over the entire size spectrum.…”

Virus transmission by ultrasonic scaler and its prevention by antiviral agent

“…Similar to a recent study on atomization from rotary dental instruments (Sergis et al 2020), the generalization of our findings into the wide variety of clinical settings is difficult due to variability of USS devices and their operating parameters, including power setting tip selection and irrigant flow rate. Even larger differences may be found between dental procedures (Allison et al 2021).…”