How deep into a periodontal pocket can subgingival air polishing reach?

The indexed literature does not provide a precise, universally agreed millimetre depth of penetration for subgingival air polishing across all tip designs, but several passages offer relevant clinical data. Early work using a conventional air-polishing device with glycine powder directed into the pocket showed sufficient biofilm removal in pockets of 3–5 mm, with adequate results observed in pockets ≤3 mm when the beam was pointed apically ^[1]. A triangular-shaped nozzle with sideways orientations for water and the air-powder beam was subsequently introduced specifically to reach deeper periodontal pockets and reduce the risk of emphysema ^[1]. The clinical trials included in this body of literature treated pockets ranging from 3 mm up to 9 mm with subgingival air polishing, suggesting devices are used across this range in practice ^[1][2][3].

It is worth noting that effectiveness appears to diminish with increasing pocket depth. One study found that air polishing alone in untreated pockets ≥6 mm produced short-term CAL gain comparable to conventional scaling and root planing, but the sequential two-step combination did not further enhance long-term outcomes ^[4]. Another trial found no significant advantage of adding subgingival air polishing over ultrasonic instrumentation alone for pockets of 7–9 mm ^[2]. Tip geometry matters considerably, as conical and sideways-oriented nozzles were developed precisely to improve access to deeper sites ^[1]. Long-term data on repeated subgingival use across all pocket depths remain limited ^[1].