Background: Dental caries remains a prevalent oral health concern among children worldwide, necessitating effective preventive measures. This study evaluates the efficacy of cranberry extract mouthwash and fluoride mouthwashes in reducing Streptococcus mutans counts among children aged 6–12 years with moderate to severe dental caries. 

Materials and methods: A randomized controlled trial was conducted involving children with three or more carious lesions [Caries Assessment Spectrum and Treatment (CAST) types 3–9]. Participants were assigned to receive either cranberry extract mouthwash or fluoride mouthwash, administered weekly for 6 months. S. mutans colony-forming units (CFUs) were assessed at baseline, 3 months, and 6 months to measure bacterial load reduction. 

Results: Both cranberry extract mouthwash and fluoride mouthwashes demonstrated statistically significant reductions in S. mutans CFUs at 3 months (p < 0.01) and 6 months (p < 0.01) compared to baseline. No significant difference was observed between the two mouthwashes, suggesting comparable efficacy in bacterial count reduction. 

Conclusion: This study supports the use of cranberry extract mouthwash as a natural alternative to fluoride mouthwash in managing dental caries among children. Both interventions effectively reduced S. mutans counts, highlighting their potential as adjuncts to conventional caries management strategies.