Effect of Desensitizing OTC Toothpaste Products Versus Fluoride Iontophoresis on Microhardness of Dentin Surface

Abstract

Objective: This study was designed to compare the effect desensitizing OTC toothpaste products versus fluoride iontophoresis on dentin surface microhardness. Materials and methods: Eighty four extracted human teeth were stored in distilled water at room temperature until use. The teeth were divided according to the remineralizing agents into four treatment groups (Bioactive glass B; n-HAP N; fluoride F & fluoride iontophoresis FI) 21 teeth each. Each group was further subdivided into three equal subgroups according to the pH cycling period (two weeks (W2), one month (M1) and two months (M2) with 7 teeth for each. Results: The results in comparison to demineralized specimen revealed that FI group the highest mean surface microhardness value, while the B, N & F groups showed lower microhardness mean values with significant difference. On the other hand, there is an increase in surface microhardness values of B, N, F groups with non-significant difference. Conclusions: Microhardness of dentin is positively affected by the application of remineralizing agent and better with fluoride iontophoresis. Increasing the application rate (pH cycling periods) of the remineralizing agents significantly positively affect the surface microhardness of dentin.