Association of Interdental Cleaning Frequency With Tooth Loss and Self-Rated Oral Health: A Cross-Sectional Study

Aims: This study investigated the associations of interdental cleaning frequency with lack of functional dentition (missing >8 teeth) and self-rated oral health status. Methods: Data from 14,154 participants aged 30 to 80 years in 2011 to 2020 US National Health and Nutrition Examination Survey were analysed using weighted multivariate Poisson regression. Results: The prevalence rates of lacking functional dentition and poor self-rated oral health were 14.6% and 9.2%, respectively. 25.8% of the participants had never performed interdental cleaning, whereas 41.5% performed interdental cleaning 5 to 7 d/wk. When the never-performed interdental cleaning group was considered as reference group, the prevalence ratio and 95% confidence interval for the associations of interdental cleaning 1 to 4 and 5 to 7 d/wk with lack of functional dentition was 0.54 (0.39, 0.75) and 0.57 (0.42, 0.77), respectively, and significant interactions of interdental cleaning frequency with race, educational levels, and metabolic syndrome were observed. Notably, interdental cleaning exhibited a synergistic relationship with higher school education but an antagonistic relationship with Black ethnicity and metabolic syndrome in association with a lower prevalence of lacking functional dentition. The prevalence ratio and 95% confidence interval for interdental cleaning 1 to 4 and 5 to 7 d/wk for poor self-rated oral health was 0.54 (0.38, 0.77) and 0.43 (0.29, 0.63), respectively. Specifically, there was antagonistic interaction effect between dental visit intervals exceeding 6 months and interdental cleaning on self-rated oral health. Conclusions: More frequent interdental cleaning was associated with more favourable self-rated oral health but not tooth loss. Higher education was synergistic but black ethnicity, metabolic syndrome, and long dental visit intervals were antagonistic with interdental cleaning in maintain natural teeth and better self-rated oral health. Interdental cleaning >= 5 d/wk cleaning, 6-monthly dental visits, and oral health education may decrease tooth loss and promote oral health. (c) 2025 The Authors. Published by Elsevier Inc. on behalf of FDI World Dental Federation. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)