Assessment of a novel bleaching agent formula containing 35% hydrogen peroxide and titanium tetrafluoride: an in vitro study.

Rodrigo Barros Esteves Lins,Vanessa Cavalli,Pedro Luiz Rosalen,Luís Roberto Marcondes Martins,Josy Goldoni Lazarini

doi:10.1590/1807-3107bor-2021.vol35.0066

Rodrigo Barros Esteves Lins, Vanessa Cavalli + Show 3 more

Open Access

https://doi.org/10.1590/1807-3107bor-2021.vol35.0066

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Abstract

This study developed experimental gels containing titanium tetrafluoride (TiF4) combined with commercial 35% hydrogen peroxide (HP), and evaluated bleaching efficacy and pH of the gels, and mineral content and morphology of enamel submitted to these treatments. In phase-1, different stock gels mixed with TiF4 were combined with HP. In phase-2, the selected gels were tested on enamel/dentin specimens (n=8): HP; HP and Natrosol+TiF4 (HPnT); HP and Natrosol+Chemygel+TiF4 (HPncT); HP and Aristoflex+TiF4 (HPaT). Bleaching was performed in four sessions (3x15min-application/session). Color (CIEL*a*b*) and whiteness index (WID) were measured after each session, whereas whiteness index differences (ΔWID), color alteration (CIELab-ΔE, CIEDE2000-ΔE00), enamel morphology and pH, at end of bleaching therapy. The change in Knoop microhardness (ΔKHN) was compared before and after bleaching. Data were analyzed by two-way repeated measures ANOVA and Bonferroni (CIEL*, a*, b*), one-way ANOVA and Tukey (ΔWID, ΔE, ΔE00), and LSD (ΔKHN) tests (α=5%). SEM and pH measurements were submitted to descriptive analysis. No differences were observed in lightness (L*) or WID among the groups (p > 0.05), but HP exhibited lower b* values (p<0.05), higher ΔWID than HPnT, and the highest ΔE among the groups (p < 0.05). No differences in ΔE00 were observed between HP and HPncT (p > 0.05), and HPncT showed higher ΔKHN than HP (p < 0.05). HP presented pH values closer to neutral (6.9), whereas experimental agents showed acidic pH values (2.3-3.9). No morphological changes were observed in HP or HPncT groups. HPncT was able to bleach the enamel and maintain enamel microhardness and surface integrity, even at low pH.

Highlights

Submitted: July 6, 2020 Accepted for publication: December 7, 2020 Last revision: February 9, 2021Minimally invasive operative dentistry focused on high esthetic criteria requires safe and effective techniques, procedures, and products
The most suitable combinations obtained in phase 1 were selected and tested in phase 2, in which enamel blocks were prepared, selected according to surface microhardness, and randomly divided into the following groups (n = 8): hydrogen peroxide (HP); HP combined with Natrosol + 4% TiF4 (HPnT); HP combined with Natrosol + Chemygel + TiF4 (HPncT); HP combined with Aristoflex + TiF4 (HPaT)
At the end of bleaching, HP and HP and Natrosol+Chemygel+TiF4 (HPncT) groups showed no differences in a* mean values (p > 0.05), but were higher than groups HP and Aristoflex+TiF4 (HPaT) and HP and Natrosol+TiF4 (HPnT) (p < 0.028)

Summary

Introduction

Invasive operative dentistry focused on high esthetic criteria requires safe and effective techniques, procedures, and products. In this respect, dental bleaching is a common clinical procedure, because it is undoubtedly an effective technique,[1] regardless of the hydrogen peroxide (HP) concentration used.[2,3]. Safety has always been a concern, since literature reports damage to the dental structure promoted by HP agents, including a decrease in microhardness,[3] an increase in roughness, tooth sensitivity, morphological changes and enamel mineral loss.[4] These adverse effects may be transitory, considering the remineralization action played by saliva or topical fluoride application.[5] using remineralizing agents like sodium fluoride (NaF),[6] or incorporating NaF into bleaching agents could be feasible alternatives for controlling or reversing enamel mineral loss.[7,8]

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