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

Abstract

This study developed experimental gels containing titanium tetrafluoride (TiF 4 ) 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 TiF 4 were combined with HP. In phase-2, the selected gels were tested on enamel/ dentin specimens (n=8): HP; HP and Natrosol+TiF 4 (HPnT); HP and Natrosol+Chemygel+TiF 4 (HPncT); HP and Aristoflex+TiF 4 (HPaT). Bleaching was performed in four sessions (3x15min-application/ session). Color (CIEL*a*b*) and whiteness index (WI D ) were measured after each session, whereas whiteness index differences (ΔWI D ), color alteration (CIELab-ΔE, CIEDE2000-ΔE 00 ), 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 (ΔWI D , ΔE, ΔE 00 ), and LSD (ΔKHN) tests (α=5%). SEM and pH measurements were submitted to descriptive analysis. No differences were observed in lightness (L*) or WI D among the groups (p > 0.05), but HP exhibited lower b* values (p<0.05), higher ΔWI D than HPnT, and the highest ΔE among the groups (p < 0.05). No differences in ΔE 00 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.

A Titanium Tetrafluoride Experimental Gel Combined with Highly Concentrated Hydrogen Peroxide as an Alternative Bleaching Agent: An In Vitro Study

“…This investigation analyzed dental bleaching ability and mineral content of enamel submitted to experimental 35% HP bleaching agents containing low concentrations of titanium tetrafluoride (0.05–0.4 g). In a previous investigation [ 17 ], our research group observed that 4% TiF (or 0.198 g) combined with Natrosol and Chemygel thickeners exhibited results similar to the HP commercial bleaching agent. This study selected the best TiF /thickener combination outcome of the first research (0.198 g TiF ), and concentrations of TiF ranged around the known concentration (0.05, 0.1, 0.2, 0.3, and 0.4 g).…”

“…Our research group recently developed an experimental gel containing TiF , Natrosol, and Chemygel [ 17 ], and this formulation was the base for the experimental groups displayed in Table 1 . The experimental gel contains Natrosol and Chemygel in different proportions, correspondent with different concentrations of TiF (0.05, 0.1, 0.2, 0.3, and 0.4 g of TiF ).…”

“…In our previous study [ 17 ], an experimental gel-based formula (Natrosol with Chemygel) containing 4% TiF associated with a commercial 35% HP agent was evaluated and we have found that this combination exhibited, in general, similar results compared with 35% HP alone. The experimental agent increased microhardness at the end of bleaching, and no enamel surface alterations were observed [ 17 ].…”

“…In our previous study [ 17 ], an experimental gel-based formula (Natrosol with Chemygel) containing 4% TiF associated with a commercial 35% HP agent was evaluated and we have found that this combination exhibited, in general, similar results compared with 35% HP alone. The experimental agent increased microhardness at the end of bleaching, and no enamel surface alterations were observed [ 17 ]. However, since that study was the first using this combination, we needed to narrow TiF concentration range and examine the efficacy of the agents according to enamel color changes, surface mineral content, morphology, and evaluate cytotoxicity of the experimental agent applied on keratynocytes cells (HaCat) [ 23 ], since oral mucosa irritation is also a common effect of bleaching procedure [ 24 ].…”

“…Our research group recently developed an agent containing titanium tetrafluoride (TiF ), Natrosol, and Chemygel to be incorporated into 35% HP bleaching gel [ 17 ]. This agent was designed for whitening purposes and to maintain enamel integrity through the bleaching procedure.…”