Reproducibility of probing attachment level measurements.

The reproducibility of probing attachment level measurements in incisors, cuspids and premolars was studied in 2 groups of patients with severely advanced periodontal disease. The results showed that approximately 90% of the recordings could be reproduced within within +/- 1.0 mm difference. This was found for intra-examiner as well as inter-examiner comparisons of 2 examiners. Measurements using onlay margins for reference point demonstrated somewhat less variability than the use of cemento-enamel junction for reference. The level of reproducibility varied notably between patients and was improved following non-surgical periodontal therapy. Also, the reproducibility varied significantly between tooth types, tooth surfaces and probing pocket depths. It was concluded that in clinical studies, the evaluation of the healing response of individual lesions should include consideration of the variability of repeated measurements for each of the investigated tooth sites.