Hyaluronic Acid‐Based Bleaching Gels With NF_TiO2 and Violet LED: Efficacy and Cytotoxicity of Low‐Concentration H2O2 for In‐Office Bleaching

Abstract

ABSTRACTObjectiveTo evaluate the efficacy and cytotoxicity of in‐office bleaching gels with hyaluronic acid (HA) or carbomer 940 (CAR), titanium dioxide nanoparticles co‐doped with nitrogen and fluorine (NF_TiO2), and hydrogen peroxide (HP; H2O2) at 1.5% and 6% with violet LED irradiation.Materials and Methods48 bovine enamel/dentin discs (5 × 3 mm) stained with black tea for 24 h were assigned to six groups (n = 8): HA‐1.5%HP + LED, HA‐6%HP + LED, CAR‐1.5%HP + LED, CAR‐6%HP + LED, 35%HP‐commercial (control), and a negative control (no treatment). The discs were placed in artificial pulp chambers (APCs) and underwent three 30‐min bleaching sessions with 20 violet LED cycles (1‐min activation, 30‐s pause) at 7‐day intervals. Extracts were applied to MDPC‐23 cells, assessing color change (ΔE00), whiteness index (ΔWID), H2O2 diffusion, cell viability (CV), oxidative stress (OxS), and cell morphology (SEM). Data were analyzed by one‐way ANOVA and Tukey post hoc test (α = 0.05).ResultsGels with HA showed no statistical difference in ΔE00 and ΔWID compared with 35%HP‐commercial (p > 0.05). H2O2 diffusion and oxidative stress were lower in 1.5% and 6% HP groups. Cell viability was higher in 1.5% HP groups (p < 0.05). There were no changes in cell morphology.ConclusionBleaching gels with HA, NF_TiO2 NPs, low H2O2 concentrations, and violet LED irradiation reduced cytotoxicity without compromising efficacy.Clinical RelevanceExperimental bleaching gels with hyaluronic acid, NF_TiO2 nanoparticles, low H2O2 concentrations, and combined with violet LED irradiation achieve similar efficacy to high‐H2O2 gels (35%). This approach also promises to reduce cytotoxic damage, providing a safer in‐office bleaching option.