A novel radiopaque resin infiltrant for managing early enamel caries

To develop a radiopaque infiltrant (RI) that can penetrate the full depth of enamel lesions, without the need for prior HCl treatment, and is detectable on clinical radiographs.

RI, comprising 2,2,2-tribromoethyl methacrylate, TEGDMA and UDMA (50:40:10 wt% respectively), was prepared and applied to artificial and natural demineralized enamel lesions (n = 6 each), without prior HCl treatment. Dental radiographs and X-ray microtomography (XMT) were taken pre- and post-infiltration to evaluate the radiopacity, and depth of the infiltration.

The artificial lesion had a low mineralized surface layer (linear attenuation coefficient (LAC) <1.5 cm^-1). Its radiopacity increased to 3.4 cm^-1 after RI infiltration with full depth penetration. In the natural lesions, the RI penetration depth increased as the original mineral concentration of the surface layer decreased. The radiopacity of the infiltrated lesion was similar to, or greater than that of normal enamel (LAC=2.4 cm^-1).

This novel RI has required viscosity to infiltrate demineralized enamel lesions without prior HCl treatment to remove the protective surface mineralized layer. Its high radiopacity is detectable in dental radiographs, allowing clinicians to assess and monitor the quality and depth of infiltrated lesions.

Clinicians are concerned about current infiltration technique due to the material's radiolucency and surface protective layer removal. This new RI, with high radiopacity and no need for HCl treatment, is expected to improve its acceptance and use in managing proximal early enamel carious lesion.