Interexaminer reliability of the assessment of clinical furcation parameters as related to different probes

The aim of this study was to investigate the interexaminer reliability of the assessment of clinical furcation diagnosis. Horizontal attachment level (PAL-H) measurements were obtained by 3 examiners in 6 molars in each of 10 patients with advanced periodontitis. In each patient, 3 molars were examined using a 3 mm incrementally marked Nabers probe, and 3 molars were examined using a pressure-calibrated plastic probe (TPS). Assignment of the probe was random, and the schedule of examiners was changed for each patient. Clinical assessments were validated by intrasurgical measurements in 6 patients. Sixty molars with 152 furcations were investigated. Multifactorial analysis of variance revealed that PAL-H measurements were significantly influenced by examiner and furcation location, whereas type of probe and schedule of examination had no influence. The overall intraclass correlation coefficient was r = 0.695. The difference between clinical and intrasurgical PAL-H assessment was influenced by examiner and location but not by type of probe. Approximately 70% of the total variance of PAL-H measurements was due to the variance of true values, whereas 30% of the variance may be explained by interexaminer and intraexaminer variance. The pressure-calibrated TPS probe failed to increase the interexaminer reliability of PAL-H measurements when compared to a Nabers probe.