To explore dietary patterns in relation to periodontitis and number of teeth.

A cross-sectional study.

We used data from the seventh survey of the Tromsø Study in Norway, 2015–2016. Three periodontitis groups were compared: (i) no periodontitis/slow bone loss; (ii) moderate bone loss; and (iii) rapid bone loss. Number of teeth was categorised as 25–28, 20–24 and ≤ 19. Dietary patterns were identified by principal component analysis. Multiple logistic regression was applied to examine associations between tertiles of dietary pattern scores and periodontitis, and between these same tertiles and number of teeth.

1487 participants (55·5 % women) aged 40–79 years who were free of major chronic diseases, attended an oral health examination and completed a FFQ.

Four dietary patterns were identified, which explained 24 % of the total variability in food intake: fruit and vegetables, Westernised, meat/fish and potatoes, and refined grain and dessert. The fruit and vegetables pattern was inversely associated with periodontitis characterised by rapid bone loss when compared with no periodontitis/slow bone loss (OR tertile 3 v. 1 0·49, 95 % CI: 0·25, 0·98). Participants who were in the highest tertile of the refined grain and dessert pattern (tertile 3 v. 1) had 2·38- and 3·52-fold increased odds of having ≤ 19 than 20–24 and 25–28 teeth, respectively.

Out of four identified dietary patterns, only the fruit and vegetables pattern was negatively associated with advanced periodontitis. A more apparent positive association was observed between the refined grain and dessert pattern and having fewer teeth (≤ nineteen teeth).