Influence of probing force on the reproducibility of bleeding tendency measurements

Three groups of seven patients were selected on the basis of about 50% loss of alveolar bone support in some part of the mouth. All patients received initial treatment consisting of plaque control and removal of subgingival deposits. In the first group of patients 95 interproximal pockets were measured three times by one examiner using the pressure probe employing a constant probing force of 0.75 N. Bleeding or lack of bleeding from a pocket was sought for up to 30 seconds after probing. Results show that a time interval of 15 minutes between reexamination procedures is enough to prevent an increased bleeding index caused by repeated probing. In the second group of patients, 98 interproximal pockets were measured three times with a Merritt-B probe (Hu-Friedy), each time by a different examiner. In the third group of patients, 102 interproximal pockets were measured three times with a pressure probe, each time by a different examiner. The same three examiners were involved. In both groups presence or absence of bleeding from a pocket was recorded. Results show a proportion of interexaminer agreement among three examiners of 0.40 with the Merritt-B probe and 0.71 with the pressure probe. It is concluded that a constant probing force of 0.75 N does contribute to more reproducible bleeding tendency measurements.