Background <p>Dental sealants are an important preventive service for reducing occlusal caries in children and adolescents. As digital health information–seeking behaviors have become increasingly prevalent, online search activities may serve as indicators of population-level interest in preventive healthcare services. Understanding how online search trends relate to actual dental sealant utilization may provide valuable insights for public health planning.</p> <p>This study aimed to examine longitudinal trends in dental sealant utilization and online search activity in South Korea from 2016 to 2023 and to assess the association between sealant utilization and online search trends.</p> Methods <p>Monthly data on patients receiving dental sealants under the National Health Insurance program were analyzed alongside relative search volume (RSV) data for “dental sealant” obtained from NAVER Data Lab. Subgroup differences in online search activity according to sex, age group, and search device were assessed. Multivariate ordinary least squares regression was performed to examine the association between RSV and sealant utilization, with adjustment for key influencing factors.</p> Results <p>Sealant utilization exhibited pronounced seasonal variation, with higher utilization during school oral examination and vacation season. Significant differences in online search activity were observed across sex, age groups, and search devices, with the highest search interest observed among individuals aged 19–39 years. Over time, mobile-based searches steadily increased and surpassed desktop-based searches. RSV was positively and significantly associated with sealant utilization after adjustment for covariates (<i>P</i>=.036). Larger population size and higher household income were associated with greater sealant utilization, whereas a higher proportion of individuals with lower educational attainment was associated with reduced utilization.</p> Conclusions <p>Online search activity was significantly associated with dental sealant utilization, suggesting that digital search trends may reflect information-seeking behavior at the population level. The increasing predominance of mobile-based searches highlights the importance of mobile-centered digital strategies for disseminating evidence-based oral health information. Integrating online search indicators with traditional utilization data may support the timing, targeting, and design of preventive dental health policies and outreach programs.</p>