Periodontitis severity, tooth loss and cognitive test scores in adults aged 60 years and older: a cross-sectional study

Introduction: Periodontitis and tooth loss have been associated with cognitive decline, but the independent contribution of each exposure across cognitive domains in older adults remains uncertain. Methods: This cross-sectional study analyzed adults aged 60 years and older in the National Health and Nutrition Examination Survey 2011-2014 with a complete full-mouth periodontal examination, tooth count and cognitive assessment. Periodontitis was classified with the CDC/AAP surveillance case definition; missing teeth were counted among 28 teeth. Outcomes were CERAD immediate and delayed recall, Animal Fluency and the Digit Symbol Substitution Test. Survey-weighted linear regression estimated beta coefficients with 95% confidence intervals, adjusted for age, sex, race/ethnicity, education, income, smoking, diabetes, body mass index and hypertension. Results: Among 2,198 participants (weighted mean age 68.9 years, 52.2% women), 35.2% had moderate and 7.3% severe periodontitis. Periodontitis severity was associated with lower scores in unadjusted models but not after adjustment. Each additional 8 missing teeth was associated with lower CERAD immediate recall (beta −0.22, 95% CI −0.43 to −0.01), CERAD delayed recall (beta −0.13, 95% CI −0.23 to −0.03), Animal Fluency (beta −0.46, 95% CI −0.69 to −0.23) and Digit Symbol Substitution Test (beta −1.84, 95% CI −2.41 to −1.28) after full adjustment. Conclusions: In older US adults, the number of missing teeth, but not periodontitis severity, was independently associated with lower cognitive performance across all assessed domains. Tooth loss may be a useful marker of cognitive vulnerability.