Effect of partial recording protocols on severity estimates of periodontal disease

OBJECTIVES: The study aim was to assess bias magnitudes of periodontal disease severity estimates for specific partial recording protocols (PRPs) in epidemiological studies. MATERIAL AND METHODS: Estimates of mean clinical attachment loss (MCAL) and mean probing pocket depth (MPPD) were derived for 20 different PRPs using full-mouth periodontal data from 1437 dentate Brazilian subjects 14-103 years old having at least four teeth. Biases, relative biases and intra-class correlations for all PRPs were evaluated. Graphical methods were used to assess how well the PRP-based estimates agreed with full-mouth scores across levels of disease. RESULTS: Slightly higher levels of disease were evidenced on lingual than on buccal sites. Seven multi-site PRPs and the Ramfjörd PRP produced small biases in MPPD (-0.17 to 0.04 mm) and MCAL with relative biases under 8% and 4% in absolute value for MPPD and MCAL, respectively. Biases for full- and random half-mouth-based PRPs were similar. The three-site random half-mouth MB-B-DL and the Ramfjörd PRPs produced the smallest biases, with relative biases <3% in absolute value for MPPD and MCAL. CONCLUSIONS: Bias for MPPD or MCAL estimates varies by site type, number of sites per tooth and number of quadrants included in the PRP.