Effect of sodium fluoride with different fluoride concentrations on remineralization of bleached enamel surface: An in vitro study

Objectives: To evaluate the effects of remineralization of three different concentrations of sodium fluoride on bleached enamel surface of human extracted teeth
Methods: Forty extracted human teeth for orthodontic reason without caries, restorations or any visible surface defects were collected and stored in 0.9% normal saline. Teeth were impregnated in cold acrylic and labial enamel surface 3X3 mm was marked for evaluation. Specimens were divided into four groups; no surface treatment was control group and microhardness value is to be considered as standard. The three groups were treated with 35% hydrogen peroxide as bleaching agent for three applications for 10 minutes. Microhardness was measure followed by sodium fluoride gel application with 10%, 15%, 20% concentration for 5 minutes to their respective groups for remineralizatin. One-way ANOVA was used to compare the results and p < 0.05 was considered significance.
Results: Microhardness significantly decreased after bleaching. Surface microhardness was increased after remineralization with 10%, 15%, and 20% sodium fluoride application but a relatively higher microhardness values were obtained with 20% Na fluoride concentration.
Conclusions: A number of tooth remineralization agent, products and procedures are reported in literature. Our study found that 20% sodium fluoride was considered better for in-office remineralizing after bleaching