For prevention of dental caries, S. mutans numbers must be reduced and prevented from returning to the original level. An antibacterial agent that is effective and also acceptable to young children can help to establish a favorable oral environment and halt the caries process.

Purpose: This study was conducted to evaluate the efficacy of topical antimicrobial (10% Povidone- Iodine) on S. mutans counts in children with Early Childhood Caries after full mouth rehabilitation. Also its effects on the clinical outcomes in terms of incidence of new caries and secondary caries were evaluated.

Method: Full mouth rehabilitation was done in 30 children (mean age 4.2 years) suffering from Severe Early Childhood Caries (SECC). Stimulated saliva samples were collected to determine the post operative baseline S. mutans counts. Thereafter the subjects were randomly divided into two groups. The experimental group received 10% Povidone Iodine at 3 months interval for a period of 12 months while the control group received placebo (deionized water) at similar intervals. Change in the S.mutans count at 6 and 12 month intervals were compared to the baseline post-operative mutans score. Results revealed that application of 10% Povidone Iodine caused a significant reduction in the rise of Streptococcus mutans levels from the baseline postoperative score after 12 months of treatment thus decreasing the oral load of the organisms. Reduction in counts; in turn decreased the relapse of caries in these children.

Conclusion: Thus oral rehabilitation coupled with regular application of 10% Povidone Iodine application can be a good alternative to control dental caries in children affected with Early Childhood Caries (ECC).

1 case of toxicity of PI after injection of 2.5ml of 10% PI into a hepatic cyst;

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4357886/