6. Comparison 8. Air cleaning system (ACS) compared to no ACS for reduction in the level of contamination in aerosols.
| Air cleaning system (ACS) compared to no ACS for reduction in the level of contamination in aerosols | ||||||
| Population: people undergoing aerosol generating procedures Setting: closed dental operatory and open clinical area Intervention: air cleaning system (ACS) Comparison: no ACS | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of sites (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with no ACS | Risk with air cleaning system (ACS) | |||||
| 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 during cavity preparation |
The mean CFU level was 105.10 | MD 66.70 CFU lower (120.15 lower to 13.25 lower) | ‐ | 4 (1 CCT)a | ⊕⊝⊝⊝ VERY LOW 1 | |
|
Reduction in level of contamination in aerosols during ultrasonic scaling |
The mean CFU level was 70.9 | MD 32.40 CFU lower (51.55 lower to 13.25 lower) | ‐ | 4 (1 CCT)a | ⊕⊝⊝⊝ VERY LOW 1 | |
| *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 | ||||||
1. Begins at 'low' as non‐randomised evidence. Downgraded 1 level for unclear risk of detection bias and reporting bias and 2 levels for imprecision due to small sample size reported in a single study