Histologic probe position in treated and untreated human periodontal tissues

This study was designed to histologically determine the relationship of the periodontal probe tip to the periodontal tissues during probing of untreated periodontal pockets and periodontal pockets treated with oral hygiene and root planing. Human, condemned, single rooted teeth with buccal probing pocket depth at least 6 mm were used. Two groups of specimens were included: 12 untreated teeth from six patients and 15 treated teeth from 10 patients. In the treated group, the effects of therapy were monitored clinically every 2 weeks until maximum improvement had taken place. A periodontal probe tip was then inserted on the buccal aspect of the tooth using 0.50 N pressure, and block section biopsies were taken. The histologic examination of the untreated teeth showed that the probe tip penetrated beyond the apical termination of the junctional epithelium and into the subjacent connective tissue by a mean of 0.45 +/- 0.34 mm, whereas in the treated specimens the probe stopped coronally to this landmark by a mean of 0.73 +/- 0.80 mm. This study demonstrated that the probe tip most often does not reach the base of the junctional epithelium in pockets treated by plaque control and root planing, and that clinical measurements of attachment levels are not reliable in determining the true histologic level of connective tissue attachment.