The development of the infiltration technique started back in the 1970's with the first low-viscosity plastic materials. However, these were never put into clinical application due to their toxicity (Robinson et al.1976). During their course of development, adhesive systems were employed for sealing carious lesions (Donly et al. 1992, Garcia-Godoy et al. 1997). These also exhibit a caries-inhibiting effect. However, it has only been possible to determine limited penetration depths. The reason for this is the surface morphology of the carious cavity, with a very limited pore volume on the surface, and the characteristics of the adhesive itself (Paris et al. 2007). In order to facilitate removal of the limiting surface layer, a hydrochloric acid gel was used for the infiltration technique in place of orthophosphoric acid gel for the adhesive technology. Using this conditioner it was possible to guarantee better penetration of the materials up to a depth of 58 µm due to an erosive removal of the surface layer (Meyer-Lueckel et al. 2007, Paris et al. 2007, 2009). In order to better utilize the capillary effect in the altered surface and to thereby increase the penetration depth of the material, monomer mixtures were developed with a high penetration coefficient. These enable a fast penetration of the infiltrant into the altered carious surface up to a depth of 750 µm (Paris et al. 2007, 2009). The sealing of the carious cavity is now no longer restricted to the surface alone, but also encompasses the body of the cavity.