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CC BY-NC-ND 4.0 · Eur J Dent 2021; 15(04): 687-693
DOI: 10.1055/s-0041-1728237
Original Article

Effects of Different Bleaching Agents on the Surface Topography and the Microhardness of Artificial Carious Lesions

Rasha Owda 
1   Department of Restorative Dentistry, Faculty of Dentistry, Biruni University, Istanbul, Turkey
,
Hande Sar Sancakli
2   Department of Restorative Dentistry, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
› Author Affiliations
Funding The present study was funded by the Research Fund of Istanbul University (project No. 21128) and FGM Dental Products Dental Group, Joinville, Santa Catarina, Brazil.
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Abstract

Objectives The aim of this study was to evaluate the effects of in-office and at-home bleaching agent applications on the surface topography and microhardness of artificially demineralized enamel.

Materials and Methods A total of 224 enamel specimens were prepared using bovine sound central incisors. 4 mm × 4 mm enamel windows were exposed on the buccal surfaces covering the remaining surface with nail varnish. Samples were immersed in a demineralizing solution for 16 hours to produce artificial caries lesions, then divided into four groups according to the bleaching agent’s type and concentration. Group I; in-office bleaching 35% hydrogen peroxide (HP) (Whiteness HP Maxx; FGM, Brazil), Group II and Group III at-home bleaching 16 and 22% carbamide peroxide CP, respectively (Whiteness Perfect). Group IV; control (not bleached). The microhardness Vickers hardness number (VHN) was measured at the baseline, after demineralization, and after bleaching consequently. The micro-surface changes of the enamel surface after demineralization and bleaching were evaluated by scanning electron microscope (SEM).

Statistical Analysis Data were evaluated by the one-way analysis of variance (ANOVA) test followed by Post Hoc Tukey’s and Fisher’s least significant difference. Tow- sided p-values were considered statistically significant at p ≤ 0.05.

Results A significant reduction was noticed in the enamel microhardness after demineralization p < 0.05. However, there is no statistically significant difference between the mean VHN of the demineralized and bleached enamel (p > 0.001). SEM images showed significant changes on the surface of the demineralized enamel after bleaching (pattern type III).

Conclusions The low and high concentrations of HP and CP bleaching agents increased the demineralization severity of artificial caries lesions without significantly altering their microhardness values.

Keywords

in-office bleaching - home bleaching - artificial caries lesions - microhardness - SEM


Publication History

Article published online:
24 August 2021

© 2021. European Journal of Dentistry. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

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