Correlation study of periodontitis with cognitive impairment

This study aimed to determine the association of periodontitis with cognitive impairment by evaluating periodontal conditions in middle-aged and elderly people of normal cognition and cognitive impairment.

Forty patients with cognitive impairment and thirty-five healthy controls were included in this study. Mini-mental state examination (MMSE) was used to evaluate the level of cognitive function in all patients and controls. Periodontal conditions including severity of periodontitis, number of remaining teeth, percentage of bleeding on probing, probing depth (PD), and attachment level (AL) were examined. Periodontal conditions were compared between patients and controls, and the correlation between periodontal conditions and cognitive-function level was analyzed. Statistical analysis was performed with SPSS 26.0.

The distribution of severity of periodontitis significantly differed between patients and controls (χ²=13.309 and P=0.001). The proportion of severe periodontitis in the cognitive-impairment group was significantly higher than that in the healthy controls (P<0.05). The percentage of sites with PD≥6 mm and AL≥5 mm in the cognitive-impairment group was higher than that in the controls, whereas the percentage of sites with PD=1-3 mm and AL=0-2 mm was higher in the controls (P<0.05). No significant difference in percentage of bleeding on probing was found in the two groups (P>0.05). Patients with cognitive impairment had fewer teeth than the controls (P<0.05). The level of cognitive function, assessed by MMSE, was positively correlated with the number of teeth and the percentage of sites with AL=0-2 mm, and it was negatively correlated with the percentage of sites with AL≥5 mm (P<0.05).

A correlation existed between periodontitis and cognitive impairment. Further study is essential to explore the specific relationship and related mechanism between periodontitis and cognitive impairment.