Randomized Clinical Trial to Prevent Early Childhood Caries With a Silver Diamine Fluoride Gel

Aim: The World Health Organization (WHO) included SDF in the WHO Model List of Essential Medicines. SDF is typically available as a 38% aqueous solution, which is runny and difficult to apply. A 38% SDF gel has been introduced but it has not been tested clinically. The objective is to compare the efficacy of SDF gel with that of NaF varnish in preventing carious lesions in preschool children when applied at half-yearly intervals over a 24-month period.

Methods / Design: This non-inferiority randomised clinical trial will recruit 1500 3- to 4-year-old children to receive either SDF gel or NaF varnish every 6 months. The primary outcome is SDF gel will be more effective than NaF varnish in preventing ECC when both are applied at half-yearly intervals at the 24-month follow-up. The same examiner will conduct all examinations at the kindergartens over 24 months. The examiner, the children, and the children's parents will be blinded to treatments. The parents will be surveyed on their child's oral health-related behaviours and socioeconomic background to allow adjustment for effect modification.

Discussion: If the result is as anticipated, clinicians can use SDF gel instead of NaF varnish to prevent ECC. As SDF gel is cost-effective, simple, non-invasive, and non-aerosol generating, it can be widely recommended for prevent early childhood caries. This study will help change the standard of preventive care. If SDF gel is adopted in Hong Kong, it could prevent kindergarten children from developing ECC, thus significantly reducing the burden of ECC among children and the related stress on their families.