An Instrumental Analysis of the Triad Association Between Sugar-Sweetened Beverages, Screen Time, and Dental Caries in Adolescents

Background: Previous studies reported screen time in association with unhealthy dietary behaviors, such as excessive intake of sugar-sweetened beverages leading to dental caries. Thus, we aimed to explore the association between screen time on mobile devices and dental caries experience in adolescents, as well as whether sugar-sweetened beverages would mediate the association. Methods: We analyzed 24,374 junior and senior high school students of age 12 to 17 years from the 2021 “Surveillance for common diseases and health risk factors among students” Project in Jiangsu Province of China. Dental caries experience was determined by the designated dentists. Screen time and consumption of sugar-sweetened beverages were self-reported and treated as a priori risk. We employed an instrumental variable (IV) approach for the current cross-sectional setting. We used the lasso technique to shortlist covariates from a range of confounding factors. Binary logistic regression or ordered logistic regression was performed where appropriate to explore the associations of screen time on mobile devices with dental caries and sugar-sweetened beverages. Results: The prevalence rate of dental caries was 38.4% in the study population. In comparison with <2 h/d screen time on mobile devices, extended screen time (≥2 h/d) was associated with higher dental caries risk (coefficient: 1.27, 95%; confidence interval: 0.80–1.75). Mediation analysis suggested that sugar-sweetened beverage intake might be an independent risk factor for dental caries, instead of the mediator between screen time on mobile devices and dental caries. None of the interaction terms under investigation was statistically significant. Conclusions: Exposure to mobile device screens and sugar-sweetened beverages was associated with dental caries in adolescents. These findings highlighted the importance of increasing awareness of potential risks owing to mobile device usage and sugar-sweetened beverages and the necessity to develop appropriate intervention strategies for school-aged adolescents.