Effect of high concentrated fluoride-based dentifrice on the hardness, roughness, and color of the bleached enamel

J Conserv Dent. 2018 Jul-Aug;21(4):433-437. doi: 10.4103/JCD.JCD_318_17.

Abstract

Context: Remineralizing agents have been recommended to restore the integrity of bleached enamel.

Aims: The aim of this study was to evaluate the effect of fluoride at high concentration (5000 ppm) applied to bleached enamel.

Materials and methods: A total of 30 specimens obtained from newly extracted third molars were divided into two groups (n = 15) as follows: control group and fluoride group. Specimens of both groups received bleaching treatment with 35% hydrogen peroxide, were then submitted to the Vickers hardness number/colorimetric test (VHN/CT) (n = 5) and Ra (n = 10) tests, and stored in artificial saliva. After bleaching, fluoride group received the application of a fluoride-based dentifrice, during 5 min. VHN, RS, and CT analysis of both groups were performed before and after treatments. For VHN, five indentations per specimen were performed, using a microdurometer. Ra analysis was performed with a rugosimeter. The color was analyzed through the CIE L* a* b* system, respectively, using a colorimeter.

Statistical analysis: For intergroup statistical analysis, ANOVA with Tukey's posttest was used. All tests were calculated at a significance level of 5%.

Results: There was statistically significant difference (P < 0.01) between the analyzed groups, on VHN, Ra, and CT evaluations.

Conclusions: The use of fluoride-based dentifrice at 5000 ppm was effective in minimizing the deleterious effects on bleached enamel.

Keywords: Colorimetry; dentistry; hardness sodium fluoride; tooth bleaching.