Dental caries on (proximal) tooth surfaces is still a problem in many industrialized countries. The objectives of this review were to present the scientific basis and the principles of the resin infiltration concept, to discuss the inherent clinical applications, and to describe how these backgrounds can be integrated into the concept of minimal intervention dentistry. Data were identified by searches of the Cochrane Registers, Medline, and Scopus. Articles published in English and German through December 2008 were selected, and most up-to-date or relevant references were chosen. Cross-referencing of significant articles identified additionally relevant articles written in other languages and those of historical value. A total of 23 in vitro studies (focusing on penetration depths or demineralization prevention) were found, and 3 clinical studies (involving 122 subjects) could be retrieved; these studies were not comparable. With an increased understanding of the caries process, it is now recognized that demineralized but noncavitated enamel lesions can be arrested or remineralized in many situations. The clinical research evidence on the resin infiltration technique currently is of moderate extent to reach any decisive conclusions; however, based on available laboratory and clinical studies, it seems convincing that resin infiltration of enamel lesions should reduce (or even stop) the progress of white spot lesions. Combining this ultraconservative restorative approach (which is considered microinvasive) with a substantial caries remineralization program may provide therapeutic benefits and significantly reduce both long-term restorative needs and costs, thus complementing the concept of minimal intervention dentistry.