Reproducibility of Manual Periodontal Probing Following a Comprehensive Standardization and Calibration Training Program

BACKGROUND: Clinical standardization and calibration training is recommended to increase the reproducibility of periodontal probing, but its impact on manual periodontal probing outcomes has received little attention. This study examined the reproducibility of manual periodontal probing performed by a periodontist after completion of a comprehensive standardization and calibration training program. METHODS: A newly-educated periodontist was subjected to an individualized periodontal probing standardization and calibration training program involving approximately 24 total hours of lecture, bench-top, and clinical instruction/evaluation. Satisfactory completion of each portion of the training program required ≥ 95% intra-examiner agreement within 1 mm between initial and repeat measurements, and a ≥ 90% level of exact agreement with measurements by a “gold standard” examiner. The periodontist then evaluated bleeding on probing (BOP) and performed duplicate measurements of probing depth (PD) and the distance between the cementoenamel junction and gingival margin (CEJ-GM) with a manual periodontal probe on 567 periodontal sites exhibiting ≥ 5 mm PD with BOP in 39 adults. Clinical periodontal attachment level (CAL) was calculated for each site as (PD) - (CEJ-GM). RESULTS: Intra-examiner measurement error (the standard deviation for a single measurement) was found to be 0.21 mm for PD, 0.15 mm for CEJ-GM, and 0.26 mm for CAL. Replicate assessments of PD and CAL yielded excellent exact agreement kappa scores of 0.86 and 0.87, respectively. Greater intra-examiner measurement error was found at periodontal sites with more gingival inflammation as measured by higher BOP index scores. CONCLUSION: These findings demonstrate that a rigorous periodontal probing standardization and calibration training program facilitates acquisition of highly reproducible PD and CAL assessments in moderate to deep inflamed periodontal pockets with a manual periodontal probe. Similar formal hands-on training should be incorporated into dental education programs and clinical research studies to improve the diagnostic performance of manual periodontal probing of the periodontium.