The Effectiveness of Topical Fluorides in Preventing Dental Caries in Children and Adolescents: A Systematic Review and Meta-Analysis.

OBJECTIVE: This study aims to assess the effectiveness of topical fluoride treatments, including mouth rinses, toothpaste, gels, foams and varnish, in preventing dental caries in children and adolescents through a systematic review and meta-analysis. It primarily focuses on the impact of different intervention frequencies, durations, concentrations, and types of fluoride on the incidence of dental caries and on changes in decayed, missing and filled surfaces (DMFS) and the surface area of initial caries (SIC) indices. METHODS AND MATERIALS: Clinical intervention studies that met the inclusion criteria were identified through searches of PubMed, Embase, Web of Science, Cochrane Library, ScienceDirect, SinoMed, Chinese National Knowledge Infrastructure and Wanfang databases. The literature search was conducted on 2 June 2025 and covered publications between 1 January 2000 and 31 May 2025. Two independent reviewers performed literature screening, data extraction and risk-of-bias assessment. A meta-analysis was performed using fixed-effects or random-effects models. Subgroup analyses and narrative heterogeneity exploration were conducted according to fluoride concentration, intervention frequency, duration, age group and control type. Safety outcomes were narratively summarised. RESULTS: The meta-analysis of 10 included clinical studies showed that topical fluoride significantly reduced caries incidence when the event was defined as development of dental caries (odds ratio [OR] = 0.27, 95% CI: 0.21-0.36, p 0.00001), prevented DMFS increment (weighted mean difference [WMD] = 0.35, 95% CI: 0.07-0.63, p = 0.01) and reduced SIC changes (WMD = -0.85, 95% CI: -1.66 to -0.05, p = 0.04). Subgroup analyses indicated superior outcomes with 0.2% fluoride, higher intervention frequency and longer duration. The 5% sodium fluoride varnish study was summarised separately because it used a professionally applied varnish and delayed-varnish control. Safety reporting was limited, and no serious fluoride-related adverse events were identified in the available reports. Formal meta-regression was not performed because the number of study-level estimates for DMFS and SIC was limited. CONCLUSION: Topical fluoride is highly effective in preventing dental caries in children and adolescents. The findings support sustained and appropriately supervised use of topical fluoride, while highlighting the need for standardised protocols and better long-term safety reporting.