Bleeding on probing

Method

Percentage of examined periodontal sites that bleed within the stated interval, usually 15 to 30 seconds, after gentle probing with a calibrated periodontal probe, scored full-mouth at six sites per tooth.

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

Notes

A dichotomous bleed or no-bleed judgement aggregated across sites into a proportion. Confused with probing pocket depth and CAT:outcome/clinical-attachment-level, obtained by the same probe stroke at the same visit but which are LENGTHS in millimetres; and with the gingival index and plaque index, which are ordinal 0 to 3 severity scores. All four fall with benefit, so the error is silent - it corrupts the unit and the effect size rather than the sign. This indexes active inflammation and responds within weeks; attachment level indexes cumulative destruction and barely moves in the same window.