ClearDefense Silver Nanoparticles: Characterisation and Safety Assessment for Children's Dental Care Off-label Use.

BACKGROUND AND

OBJECTIVES

We characterised an Ag-Chitosan-NaF product (ClearDefense), marketed for off-label use in caries arrest in children, as an alternative to 38% silver diamine fluoride (SDF). The label lists 0.2% Ag+ and 1.36% F-. No child efficacy or safety studies are reported.

METHODS

We followed U.S. National Institute of Standards and Technology (NIST) guidelines to describe the composition and stability of the product and assess its safety for children.

RESULTS

The product features heterogeneous AgNPs: 86% irregular spherical (32 ± 26 nm), 6% triangular (101 ± 100 nm), and 8% rod-shaped (42 ± 28 nm length, 16 ± 10 nm width). Ag-Chitosan-NaF exhibits agglomeration with Chitosan and NaF, and stability studies reveal an increase in Ag+ ion concentration upon exposure to air, raising concerns about dosage variations. Toxicity assessment reports a Margin of Exposure (MOE) for preschool children of 8-20 mg/kg, based on application amount and a 100X correction factor.

CLINICAL SIGNIFICANCE: This Ag-Chitosan-NaF product requires refinement to meet the standards for formulation, purity, and safety for paediatric off-label use.

CONCLUSIONS

ClearDefense differs from the FDA-approved 38% SDF, raising concerns about consistency and paediatric suitability. A thorough reassessment by the manufacturer is needed to meet paediatric clinical standards.