Interventions to Reduce Aerosolized Microbes in Dental Practice: A Systematic Review with Network Meta-analysis of Randomized Controlled Trials

J Dent Res. 2020 Oct;99(11):1228-1238. doi: 10.1177/0022034520943574. Epub 2020 Jul 13.


The aim of this systematic review and network meta-analysis was to identify and rank the effectiveness of different interventions used in dental practice to reduce microbial load in aerosolized compounds. Seven electronic databases were searched to April 6, 2020, for randomized controlled trials (RCTs) or nonrandomized prospective studies in the field. Study selection, data extraction, and risk-of-bias assessment were performed for all included studies, while the outcome of interest pertained to differences in bacterial load quantification through the use of different interventions prior to aerosol-generating procedures in dental practices. Random effects frequentist network meta-analysis was performed, with mean difference (MD) and 95% CI as the effect measure. Confidence in the documented evidence was assessed through the newly fueled CINeMA framework (Confidence in Network Meta-analysis) based on the GRADE approach (Grading of Recommendations, Assessment, Development and Evaluation). Twenty-nine clinical trials were deemed eligible, 21 RCTs and 8 nonrandomized studies, while 11 RCTs contributed to the network meta-analysis, comprising 10 competing interventions. Tempered chlorhexidine (CHX) 0.2% as compared with nonactive control mouth rinse, prior to routine ultrasonic scaling, was most effective toward reduced postprocedural bacterial load with an MD of -0.92 (95% CI, -1.54 to -0.29) in log10 bacterial CFUs (colony-forming units). For CHX 0.2%, an MD of -0.74 (95% CI, -1.07 to -0.40) was observed as compared with control. Tempered CHX 0.2% presented the highest probabilities of being ranked the most effective treatment (31.2%). Level of confidence varied from very low to moderate across all formulated comparisons. These findings summarize the current state of research evidence in the field of aerosolized bacteria in dentistry. Instigated by the era of SARS-CoV-2 pandemic, the stipulation of a broader evaluation of the aerosolized microbes, including viruses, potentially coupled with disinfectant-based prevention schemes should be prioritized.

Keywords: SARS-CoV-2; aerosol; bacteria; debonding; mouth rinse; ultrasonic scaling.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Aerosols*
  • Bacterial Load
  • Betacoronavirus
  • COVID-19
  • Coronavirus Infections / prevention & control*
  • Dentistry / methods*
  • Disinfectants*
  • Humans
  • Network Meta-Analysis
  • Pandemics / prevention & control*
  • Pneumonia, Viral / prevention & control*
  • Prospective Studies
  • Randomized Controlled Trials as Topic
  • SARS-CoV-2
  • Viral Load


  • Aerosols
  • Disinfectants