Public Perception of Fluoride: An Infodemiological Analysis of YouTube Videos and Comments

OBJECTIVE: This study aimed to analyze the public's perception of fluoride by investigating the most-viewed YouTube videos and their associated comments addressing fluoride in dental/public health contexts. METHODS: Metadata and comments of YouTube videos were retrieved using the YouTube Data application programming interface (YouTube Data API) via Python. The top 100 most-viewed YouTube videos related to fluoride and their comments were analyzed. Sentiment analysis, Latent Dirichlet Allocation (LDA) topic modeling, word co-occurrence analysis, and word frequency analysis were performed. Statistical analyses including Spearman's correlation, Kruskal-Wallis tests, and Mann-Whitney U tests were conducted to assess potential associations. RESULT: A total of 76 eligible videos and 88,126 comments were analyzed. Approximately half (45%) of the retrieved videos were uploaded in 2024 and 2025. The mean (±standard deviation) and median sentiment scores were 9.5 ± 15.9 and 5.4, respectively. Significant negative correlations were observed between sentiment scores and both video views (r = -0.247, P = 0.032) and the number of comments (r = -0.486, P < 0.001). Among professional uploaders, videos by dental hygienists had a higher sentiment score compared with those by dentists (17.5 vs. -0.5). Topic modeling revealed that the term "poison" appeared 6 times more frequently in negative comments than in positive comments, followed by "conspiracy" and "bad," whereas "love," "care," and "safe" were predominant in positive comments. CONCLUSION: Fluoride has emerged as a controversial societal topic. The terms "poison" and "conspiracy" reflect prominent public concerns. Dental hygienists play a critical role in disseminating online information on fluoride, highlighting the need for targeted strategies to mitigate public anxiety and promote the appropriate use of fluoride in dental care.Knowledge Transfer Statement:The present study provides insights into public health communication. First, empowering professionals and optimizing video formats (eg, tutorials, skills-based demonstration, and short dramas) could enhance the reach and acceptance of evidence-based fluoride advocacy. Second, policymakers should address societal and historical factors shaping public distrust, rather than relying solely on scientific dissemination. Finally, due to contagion of negative emotions, there is a need to monitor and alleviate negative sentiments.