Association between diet quality and untreated dental caries: results from the Korea National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES: Few studies have provided evidence of the association between diet quality and dental caries. This study aimed to examine the association between diet quality and untreated dental caries in a Korean representative population. SUBJECTS/METHODS: The study population included a sample of 13,815 participants, aged ≥ 19 from the Korea National Health and Nutrition Examination Survey during 2013–2015. The explanatory variable was diet quality and the outcome variable was untreated dental caries. Untreated dental caries were defined by the number of decayed teeth recorded according to the criteria established by the World Health Organization. Diet quality was defined by using the Korean Healthy Eating Index (KHEI) through the 24-h recall methods. We assessed the association between diet quality and untreated dental caries while adjusting for age, sex, education, income, smoking status, dental visits, toothbrushing frequencies, obesity, and diabetes mellitus. RESULTS: The mean overall KHEI scores in the untreated dental caries group were significantly lower than those in the group without untreated dental caries. Significant differences were observed in the untreated dental caries group based on the KHEI quartiles (P < 0.001). After adjusting for potential confounders, the quartiles of KHEI scores showed an association with untreated dental caries, demonstrating a dose-effect trend (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.35–1.84 for 1st quartile; OR, 1.38; 95% CI, 1.19–1.59 for 2nd quartile; OR, 1.32; 95% CI, 1.14–1.53 for 3rd quartile; reference quartile highest]). CONCLUSIONS: The findings indicated an inverse association between diet quality and untreated dental caries in Korean adults. Healthcare providers should take into account the significant role of diet quality in preventing and managing oral health.