Dental periodontal procedures: a systematic review of contamination (splatter, droplets and aerosol) in relation to COVID-19

Abstract

Introduction The emergence of the SARS-CoV-2 virus and subsequent COVID-19 pandemic has had a significant effect on the delivery of routine dentistry; and in particular, periodontal care across the world. This systematic review examines the literature relating to splatter, droplet settle and aerosol for periodontal procedures and forms part of a wider body of research to understand the risk of contamination in relation to periodontal care procedures relevant to COVID-19. Methods A search of the literature was carried out using key terms and MeSH words relating to the review questions. Sources included Medline (OVID), Embase (OVID), Cochrane Central Register of Controlled Trials, Scopus, Web of Science and LILACS, ClinicalTrials.Gov. Studies meeting inclusion criteria were screened in duplicate and data extraction was carried out using a template. All studies were assessed for methodological quality and sensitivity. Narrative synthesis was undertaken. Results Fifty studies were included in the review with procedures including ultrasonic scaling (n = 44), air polishing (n = 4), prophylaxis (n = 2) and hand scaling (n = 3). Outcomes included bacterial (colony-forming units e.g. on settle plates) or blood contamination (e.g. visible splatter) and non bacterial, non blood (e.g. chemiluminescence or coloured dyes) contamination. All studies found contamination at all sites although the contamination associated with hand scaling was very low. Contamination was identified in all of the studies even where suction was used at baseline. Higher power settings created greater contamination. Distribution of contamination varied in relation to operator position and was found on the operator, patient and assistant with higher levels around the head of the operator and the mouth and chest of the patient. Settle was identified 30 min after treatments had finished but returned to background levels when measured at or after an hour. The evidence was generally low to medium quality and likely to underestimate contamination. Conclusion Ultrasonic scaling, air polishing and prophylaxis procedures produce contamination (splatter, droplets and aerosol) in the presence of suction, with a small amount of evidence showing droplets taking between 30 min and 1 h to settle. Consideration should be given to infection control, areas of cleaning particularly around the patient and appropriate personal protective equipment, with particular attention to respiratory, facial and body protection for these procedures. In addition, the use of lower power settings should be considered to reduce the amount and spread of contamination.

Aerosol exposure of staff during dental treatments: a model study

“…Droplets are larger than aerosols and tend to settle faster [ 7 ]. The size of aerosols is not conclusively defined and, depending on the publication, usually varies from less than 5 µm to less than 50 µm in diameter [ 8 ]. While larger droplets carry a greater virus load and tend to deposit in the upper airway, smaller aerosols penetrate deep into the lungs [ 9 ].…”

Aerosol generated by dental procedures: A scoping review

“…The results highlight the need to use additional PPEs, with special attention to respiratory, facial and body protection, for the dentist, assistant, and patient. 11,80 The use of high-volume suction is also nec-essary to reduce the spread of aerosols and spatter. 18,27,42,52 Since the contaminated area is not restricted to the proximity of the dental chair, it is essential to control the number of people in the dental office and the waiting room, reducing the risk of cross-infection.…”

“…79,81 Cleaning areas, particularly around the patient, should be done as an infection control measure. 80 An effective form of biodecontamination was presented through the vaporization of hydrogen peroxide in the entire clinical environment, respecting the standardized protocol for its application. 82 Other measures that can reduce the possibility of contamination are the use of exhaust fans inside the dental office to allow air renewal; the periodic cleaning of air conditioning units and surfaces; and the change of physical barriers after each patient.…”

Application of recommended preventive measures against COVID-19 could help mitigate the risk of SARS-CoV-2 infection during dental practice: Results from a follow-up survey of French dentists

“…This is consistent with the results of our first study. Not only periodontologists seem to be highly exposed to airborne droplets [ 26 , 27 ], but they also spend time on clinical interviews or examinations during which they could be infected especially if they did not wear specific PPE mask or wear it incorrectly [ 28 ]. This assumption could be extended to practice limited to pediatric dentistry, which was associated with increased odds of COVID-19 in the univariate analysis.…”