Comparative evaluation and effect of organic and inorganic fluoride dentifrices on enamel microhardness: An in vitro study

Aim: To compare and evaluate the microhardness of enamel surface after the application of organic fluoride and inorganic fluoride dentifrices. Materials and Methods: Twenty freshly extracted premolars were collected and decoronation of all the teeth was done at cementoenamel junction. The crowns were sectioned mesiodistally into two halves with the help of diamond disc, and then the subsequent forty samples kept in 1% citric acid for the demineralization and divided into two groups by simple randomization, that is, Group A (inorganic sodium fluoride dentifrice) and Group B (organic amine fluoride dentifrice). They were treated using same protocol for 3 min, daily twice for 7 days. Those samples preserved in artificial saliva in between treatment. The enamel surface microhardness evaluated using Vickers hardness test at base level, after demineralization, as well as after remineralization. Statistical analysis of surface microhardness obtained at different stages done by Student's t-test and P < 0.05 was considered statistically significant. Results: The samples which were treated with sodium fluoride (Group A) could not restore the mean microhardness after treatment to that of preoperative level whereas amine fluoride (Group B) treated samples showed a statistically significant increase in mean surface microhardness from baseline. Conclusion: Organic fluoride (amine fluoride) remineralization was more effective in restoring enamel microhardness than inorganic fluoride (sodium fluoride) remineralization.