Evaluation of the effects of single and combined use of sodium fluoride and strontium chloride solutions on the remineralization of initial enamel lesions

Today, various forms of fluoride are used in dental practice both individually and professionally to prevent tooth decay. Recently, with the emergence of parents' concerns about the harmful effects of fluoride, researchers have begun to search for alternatives to fluoride, agents that will prevent carious lesions. Strontium, which is also included in restorative materials, is recommended as an alternative agent. Fluoride and strontium both have a positive effect on the remineralization process. However, the combination of strontium and fluoride may have advantages over either ion alone. Fluoride and strontium have been reported to improve apatite crystals when combined and are associated with significant reductions in acid reactivity. There are no sufficient studies on the effect of combined use of fluoride and strontium on remineralization. This study aimed to investigate the effect of single and combined application of fluoride and strontium solutions on the remineralization of initial enamel lesions. The buccal surfaces of 35 third molar teeth extracted for various reasons were divided into 4 regions and NaF, SrCl2 and NaF+SrCl2 combinations were applied. Initial surface microhardness was measured before artificial caries lesions were created by demineralization on the teeth. Then, the teeth were kept in demineralization solution for 96 hours and their surface microhardness was measured again. After the solutions were applied to the relevant areas of the teeth, they were subjected to a 21-day pH cycle. At the end of 21 days, surface microhardness measurements were made again from 3 different areas. The difference between the initial and post-demineralization surface microhardness is statistically significant. Between the surface hardness values measured after demineralization and after applying the solutions and the differences between the initial surface hardness and the surface hardness values measured after applying the solutions were found to be statistically significant. There was no statistically significant difference in surface microhardness values between the surfaces on which NaF, SrCl2 and their combinations were applied. Surface recovery was found to be statistically significantly higher in the NaF applied group compared to the other groups. When the findings of the study were evaluated, it was seen that the application of SrCl2 could be effective in the remineralization of enamel, although it was not as effective as NaF. This issue needs to be evaluated with further research. This application can be offered as an alternative to individuals and patients who have concerns about fluoride. Keywords: fluorid, strontium, microhardness, remineralization