Penetration coefficients of commercially available and experimental composites intended to infiltrate enamel carious lesions

Objectives Arresting of enamel lesions by infiltration with light curing composite resins might be a treatment alternative of future micro-invasive dentistry. So far only commercially available adhesives and fissure sealants have been used to infiltrate enamel lesions. Since these products have been optimized for adhesive purposes, the aim of this study was to develop optimized resins for the infiltration of enamel lesions and to measure their physical properties. Methods The penetration coefficients (PCs) of five adhesives and a fissure sealant as well as 66 experimental composite resins were determined. To establish the resins’ PCs the viscosities, surface tensions, and contact angles to bovine enamel were measured. Results For the commercially available products PCs from 4.0 to 278.9 cm/s were measured. Four of these materials showed a good correlation with penetration depths obtained in a previous study. Experimental composites showed PCs from 0.2 to 474.9 cm/s. The addition of ethanol significantly increased the PCs due to a decrease of viscosity and contact angle. Highest PCs were found for mixtures containing TEGDMA, HEMA and 20% ethanol. Significance The knowledge about the PC of resin composites seems to be useful for the development of new materials optimized to infiltrate enamel lesions.