Table 2.
Aerosol-suppressing equipment and corresponding air/water flow rates. Low-volume suction was used in all intervention groups. In this study, the air cleaning system flow rate was equivalent to approximately 24 air changes per hour
| Intervention | Equipment | Water flow (L min-1) | Air flow (L min-1) | Air changes per hour (in a 35 m3 surgery) |
|---|---|---|---|---|
| Low-volume suction | Plastcare USA, 4 mm slow-speed salivary ejector | 2.4 | 79 | - |
| High-volume suction (intraoral) | Dürr Universal Cannula III 16 mm, connected to Dürr Dental VSA 300S Dürr Dental UK, Kettering, UK | - | 297 | - |
| High-volume suction (extraoral) | Eighteeth VacStation,* Sifary Medical Technology, Jiangsu, China | - | 3,700 | 6 |
| Air cleaning system | Woodpecker Q7 Plasma Air Purifier,** Guilin Woodpecker Medical Instrument Co, Guilin, China | - | 14,167 | 24 |
|
Key: * = the VacStation contains two H13-grade HEPA filters (lower particle size limit 0.3 μm) with a post-filter UVC light sterilisation stage ** = the Q7 air cleaning system is a filterless instrument which operates on a high-voltage plasma purification process with integral ion chamber sterilisation stage; the lower particle size limit is reportedly 14.6 nm | ||||