Summary of findings 1. Comparison 1. High‐volume evacuation (HVE) compared to no HVE for reducing the level of contamination in aerosols.
| High‐volume evacuation (HVE) compared to no HVE for reducing the level of contamination in aerosols | ||||||
| Population: people undergoing aerosol generating procedures Setting: closed dental operatory Intervention: high‐volume evacuation (HVE) Comparison: no HVE | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with no HVE | Risk with HVE | |||||
| Rate of infection of dental staff or patients | Not reported | |||||
| Reduction in volume of contaminated aerosols in the operative environment | Not reported | |||||
|
Reduction in level of contamination in aerosols (CFU/mm³) during ultrasonic scaling and air polishing at less than 1 foot from oral cavity |
The mean CFU level ranged from 13.50 to 107.13 | MD 47.41 CFU lower (92.76 lower to 2.06 lower) | ‐ | 122 (3 RCTs)a b c | ⊕⊝⊝⊝ VERY LOW 1 | 2 CCTs found an imprecise result that crossed the line of no effect (−50.19, 95% CI −109.71 to 9.33). |
|
Reduction in level of contamination in aerosols (CFU/mm³) during ultrasonic scaling and air polishing at more than 1 foot from oral cavity |
The mean CFU level was 12.50 | MD 1 CFU lower (2.56 lower to 0.56 higher) | ‐ | 80 (1 RCT)c | ⊕⊝⊝⊝ VERY LOW 2 | 1 CCT found a reduction in contamination with HVE at the same distance (MD −13.56, 95% CI −23.18 to −3.94, 30 participants). |
| *The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CFU: colony‐forming units; CI: confidence interval; MD: mean difference; RCT: randomized controlled trial | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect Moderate certainty: we are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low certainty: our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low certainty: we have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect | ||||||
aKing 1997, bMuzzin 1999cDesarda 2014
1. Downgraded 1 level for unclear risk of bias in at least 2 domains, 2 levels for inconsistency due to substantial heterogeneity and 2 levels for imprecision due to wide confidence intervals
2. Downgraded 1 level for unclear risk of selection bias and reporting bias and 2 levels for imprecision due to wide confidence intervals