Progression of artificial enamel caries lesions after infiltration with experimental light curing resins

The arrest of enamel caries lesions by infiltration with low-viscosity light curing resins might be a promising approach of microinvasive dentistry. However, no materials optimized for rapid lesion infiltration ('infiltrants') are commercially available today. The penetration coefficient (PC) of experimental resins has been shown to correlate with penetration speed and, therefore, might be an important feature of infiltrants. The aim of the present study was to evaluate the influence of PC and composition of experimental infiltrants on the progression of enamel lesions in a demineralizing environment. Artificial enamel lesions were prepared in a demineralization solution for 50 days and infiltrated with either one of twelve experimental infiltrants or a commercially available adhesive for 10, 22, and 40 s, respectively. Specimens were cut perpendicularly to the surface and one half of each specimen was exposed to a demineralizing solution for another 50 days, whereas the other half was used as baseline control. Lesion progression was analyzed using confocal microscopy (CLSM) and transversal microradiography (TMR). The square root of the product of PC and application time was negatively correlated with progression of lesion depth (CLSM: r = -0.741; TMR: r = -0.450). Therefore, infiltrants should preferably have high PCs to facilitate inhibition of lesion progression efficiently.