Clinical attachment level (CAL) gain

Method

Change from baseline in the distance from the cemento-enamel junction to the base of the periodontal sulcus, measured with a manual or pressure-calibrated periodontal probe at defined sites and expressed as gain in millimetres. Probe type, number of sites per tooth, and examiner calibration recorded on the edge.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

CRITICAL SIGN INVERSION built into this literature. The same probe, the same site and the same millimetres are reported two ways: as a raw attachment level, a distance from the cemento-enamel junction that improves by FALLING, and as attachment gain from baseline, which improves by RISING. This node is the gain form only; a raw distance must be sign-corrected before it becomes an edge here, and papers using both conventions appear in the same review. Also distinct from probing pocket depth reduction, measured from the gingival margin rather than the cemento-enamel junction and therefore moved by gingival recession independently of any true attachment change.