Probing Depth
Also written as: PD — Probing Depth
The distance in millimetres from the gingival margin to the base of the gingival sulcus or periodontal pocket, measured with a calibrated periodontal probe.
Full Definition
Probing depth (PD) is a fundamental clinical measurement recorded during a periodontal assessment to quantify the depth of the space between the tooth and the surrounding gingival tissue. Values of 1–3 mm are typically considered healthy in adults; readings of 4 mm or more may indicate a periodontal pocket and disease activity. Editors must distinguish 'probing depth' from 'clinical attachment level' (CAL), which additionally accounts for recession from the cementoenamel junction. PD values are routinely entered into dental charting software and referenced in treatment plans, referral letters, and clinical trial data. The term is always hyphenated when used as a compound modifier: 'probing-depth measurements'.
Usage
Usage note: Distinguish clearly from clinical attachment level (CAL) in any document where both measurements are cited.
In Context
- "Probing depths of 5–7 mm were recorded at multiple sites, indicating moderate generalised periodontitis." — Periodontal screening record
- "Authors must clarify whether reported values refer to probing depth or clinical attachment level, as the two metrics are not interchangeable." — Peer review comment