Effect of Fluoride Gels on Microhardness and Surface Roughness of Bleached Enamel

Ana L.P China 1, Nayara M Souza 1, Yasmin do S. B. de L Gomes 1, Larissa D Alexandrino 1, Cecy M Silva 2, *
1 1Student, School of Dentistry, Federal University of Para, Para, Brazil
2 2School of Dentistry, Federal University of Para, Para, Brazil

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 290
Abstract HTML Views: 55
PDF Downloads: 49
Total Views/Downloads: 394
Unique Statistics:

Full-Text HTML Views: 138
Abstract HTML Views: 46
PDF Downloads: 45
Total Views/Downloads: 229

Creative Commons License
© China et al.; Licensee Bentham Open.

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at the Augusto Correa Street no1, Guamá, Belém, Pa, Brazil, CEP: 66075-110; Tel: +559132521269; E-mail:


The effect of bleaching treatments containing added calcium and combined with neutral or acidic fluoride gels on tooth enamel was investigated in vitro through Knoop microhardness (KHN) and surface roughness (SR) measurements. A total of 60 bovine incisors were tested, including 30 for SR measurements and 30 for KHN measurements. The specimens were divided into 12 groups and subjected to a bleaching agent with hydrogen peroxide 35% (Whiteness HP 35% Maxx, FGM) or hydrogen peroxide 35% with calcium (Whiteness HP 35% Blue Calcium, FGM) and a fluoride treatment flugel acidulated phosphate fluoride (APF) or flugel neutral fluoride (NF). Control specimens were submitted to bleaching treatments without fluoride. Microhardness tests were performed using a Knoop indentor. Roughness measurements were obtained using a roughness analyzer. Measurements were obtained before and after treatment. The specimens were stored in distilled water at 37 °C between treatments. The results were analyzed using descriptive and inferential statistics. Treatments using APF combined with 35% HP caused a decrease in microhardness, while NF combined with HP 35% Ca increased the enamel hardness. Fluoride gels did not alter the SR of the bleached enamel.

Keywords: Dental Enamel, Flugel, Microhardness, Peroxides, Roughness, Tooth Bleaching.