Reproducibility of attachment level recordings using an electronic and a conventional probe

This study describes the variations in the reproducibility of attachment level recordings for different subjects at different examinations. Twenty patients with different degrees of periodontal disease were recruited and examined bi-monthly for their attachment levels using an electronic probe in two quadrants and a conventional probe in the other two quadrants. At each of the 7 examinations attachment level recordings were repeated with the appropriate probe after approximately 30 minutes. Results demonstrate that the reproducibility of attachment level recordings was slightly better for the conventional probe than for the electronic probe. Attachment level recording reproducibility varied considerably between subjects and between examinations for the same subject. Aggregation of attachment level recordings in the form of mean tooth values or mean individual values reduced the range of the differences, but considerable between-subject and between-examination variation was still seen. These results indicate that no single uniformly valid estimate of attachment level reproducibility exists which can be used to set diagnostic thresholds such that a minimum number of incorrect diagnoses are made.