Probing Depth
The distance in millimetres from the gingival margin to the base of the periodontal pocket, measured with a calibrated periodontal probe.
Full Definition
Probing depth (PD) is a fundamental periodontal parameter recorded during a Basic Periodontal Examination (BPE) or full periodontal charting. It represents the depth to which a standardized probe can be inserted into the sulcus or pocket at six designated sites around each tooth. Values above 3 mm are generally considered pathological, and readings of 6 mm or above typically indicate advanced periodontal disease requiring specialist intervention. Editors reviewing periodontal charts and referral letters should confirm that probing depth is clearly distinguished from 'attachment level' (which accounts for gingival recession).
Usage
Usage note: Do not use 'probing depth' and 'clinical attachment level' interchangeably; they differ in how gingival recession is accounted for.
In Context
- "Probing depths of 7–9 mm were recorded in the molar region, indicating severe chronic periodontitis." — Periodontal charting record
- "The referral letter distinguished probing depth from clinical attachment level to clarify the extent of bone loss." — Specialist periodontal referral