Aim. The aim of the study was to investigate the usefulness of an experimental fluoride toothpaste supplemented with Sr2+ for enamel remineralization. Material and methods. Two experimental groups comprised volunteers aged 20–30 years who had all the oral cavity sanation procedures carried out and all the primary and secondary caries lesions filled before undergoing investigations. The material included twenty healthy premolar teeth extracted for orthodontic reasons due to their abnormal position in the arch or to teeth crowding in 12–14 year old children. The teeth were sectioned into blocks and artificially demineralized. The samples were placed in the oral cavity on the buccal surfaces of the first molar teeth of volunteers who used toothpaste supplemented with Ca2+, P043-, F- (group I), toothpaste supplemented with Ca2+, P043-, F-, Sr2+ (group II) and control toothpaste supplemented with Ca2+, P043- (Hydroxyapatite-HAP). The content of calcium and phosphorus was analyzed on the lateral walls of the enamel lesions, at preselected depths of 15 Î1m and 100 Î1m, by using EDS microanalysis. Results. After three months, the content of calcium in both studied groups was significantly lower at 15 Î1m and 100 Î1m of enamel depth than at the baseline (immediately after enamel demineralization). After six months, the content of calcium was lower only at 15 Î1m in both groups. At 100 Î1m of depth the calcium content was significantly higher in group II and the reference group (HAP). After three months the phosphorus content was significantly lower in group II at 15 Î1m. After six months the content of phosphorous was significantly higher in group II at 15 Î1m and 100 Î1m of enamel depth. Conclusion. The results suggest that supplementation of fluoride toothpaste with strontium improved the effect of enamel remineralization