The aspiration of modern dental medicine is to treat dental diseases with the least possible aggressive procedure in order to avoid unnecessary removal of healthy tissues. One such procedure is the infiltration of congenitally less mineralized or demineralized enamel are as in the initial caries with a special resin to fill the damaged area with a material having tooth-like properties and to stop the spread of the disease. This procedure can be performed on flat and proximal surfaces of the tooth. On flat surfaces, enamel demineralization and initial caries are seen as a white spot, and resin infiltration fills the porosities leading to a change in the optical properties and an improvement in the aesthetic appearance of the tooth surface. The materials used in this procedure have been on the market for many years and so far no harmful effects have been observed. The procedure has also been confirmed by a large number of experts, and a large number of scientific papers have been published on its effectiveness. This academic research paper describes the method of the resin infiltration in the area of flat surfaces of the front teeth through case reports. Three patients of the Department of Endodontics and Restorative Dentistry at School of Dental Medicine, University of Zagreb with white spots on the labial surfaces of the incisors caused by hypomineralization underwent a procedure of infiltration with resin materials. The results of the procedure are documented by photographs.