Assessment of partial-mouth periodontal examination protocols for periodontitis surveillance.

OBJECTIVE: To evaluate bias associated with nine identified partial-mouth periodontal examination (PMPE) protocols in estimating periodontitis prevalence using the periodontitis case definition given by the Centers of Disease Control and Prevention and American Academy of Periodontology (CDC/AAP). MATERIAL AND METHODS: Prevalence from full-mouth examination was determined in a sample of 3667 adults >/=30 years old from the National Health and Nutrition Examination Survey (NHANES) 2009-2010. Prevalence, absolute bias, relative bias, sensitivity and inflation factor were derived for these protocols according to the CDC/AAP definition and half-reduced CDC/AAP definition as </=50% of sites were measured. RESULTS: Bias in moderate and severe periodontitis prevalence ranged between 11.1-52.5% and 27.1-76.3% for full-mouth mesiobuccal-distolingual protocol and half-mouth mesiobuccal protocol respectively; according to the CDC/AAP definition. With half-reduced CDC/AAP definition, half-mouth four sites protocol provided small absolute bias (3.2%) and relative bias (9.3%) for the estimates of moderate periodontitis prevalence; corresponding biases for severe periodontitis were -1.2% and -10.2%. CONCLUSION: Periodontitis prevalence can be estimated with limited bias when a half-mouth four sites protocol and a half-reduced CDC/AAP case definition are used in combination.