Examiner Reliability using the ″Walking″ Probe Technique

The established NHANES probing technique (un-angled method) has been used in population-based studies due to the perception that this method provided more reliable measures than the standard probing technique (walking method) used to determine the deepest pocket depth within each sextant in the clinical assessment of periodontal health. A previous presentation by the authors has shown that the un-angled method of probing compared to the standard method underestimates periodontal disease status. Objectives: The purpose of this study was to determine intra and inter-examiner reliability using the standard ″walking″ probe technique. Methods: Two-day calibration sessions were conducted to train examiners (n=43) in the collection of periodontal data on subjects who exhibited varying degrees of periodontal health. Exams were conducted using a UNC-12 periodontal probe with one millimeter markings. Each subject was examined by the standard examiner and examiner trainee and then re-examined the following day resulting in 215 pairwise comparisons. Periodontal measurements included sulcular pocket depth (PD) and cementoenamel junction (CEJ) measurements within one millimeter on six sites per tooth. Clinical attachment levels (CAL) were calculated from the PD and CEJ measurements. Data from examiner sessions were included in the analyses. Reliabilities were measured using percent agreement (PA), intraclass correlation (ICC), and Kappa (K) statistics. Results: PD means (SD) for both the inter and intra-rater results were excellent. The inter-rater reliability was PA= 92.1(4.1), ICC= 0.95(0.04), and K=0.91(0.05) for probing. The intra-rater reliability was PA= 95.6(0.79), ICC= 0.97(0.01), and K=0.95(0.009). Similar measures were reported for CAL with inter-rater results PA= 91.0(4.2), ICC= 0.89(0.07), and K=0.87(0.06). Intra-rater results for CAL were PA= 94.7(1.83), ICC= 0.94(0.03), and K=0.92(0.02). Conclusions: Excellent to outstanding intra-examiner reliability within one millimeter was demonstrated using the ″walking″ probe technique for PD, CEJ, and CAL measurements. This technique appears to be reliable for use in clinical studies.