The present invention refers to a method of infiltrating enamel for the prevention and/or treatment of carious lesions comprising (a) exposing an enamel area to a conditioner comprising hydrochloric acid; (b) exposing the conditioned enamel area to an infiltrant; and (c) curing the infiltrant. The present invention further refers to a kit for carrying out the method of infiltrating enamel, which comprises a conditioner comprising hydrochloric acid and an infiltrant comprising at least one low viscous dental resin. Alternatively, the kit comprises ready-to-use means for carrying out the method of infiltrating enamel, e.g. application strips with delivery pads soaked with conditioner or infiltrant. The present invention also refers to a method for identifying an infiltrant by calculation of the penetration coefficient, and to an infiltrant identified by the method having a penetration coefficient of >50 cm/s or comprising a low viscous light curing resin having a penetration coefficient of >50 cm/s.