Enhanced tooth bleaching with a hydrogen peroxide/titanium dioxide gel

This study aimed to explore the effects of the titanium dioxide (TiO₂) concentration and particle size in hydrogen peroxide (HP) on tooth bleaching effectiveness and enamel surface properties.

TiO₂ at different concentrations and particle sizes was incorporated into 40% HP gel to form an HP/TiO₂ gel. The specimens were randomly divided into 8 groups: C1P20: HP + 1% TiO₂ (20 nm); C3P20: HP + 3% TiO₂ (20 nm); C5P20: HP + 5% TiO₂ (20 nm); C1P100: HP + 1% TiO₂ (100 nm); C3P100: HP + 3% TiO₂ (100 nm); C5P100: HP + 5% TiO₂ (100 nm); C0: HP with LED; and C0-woL: HP without LED. Bleaching was conducted over 2 sessions, each lasting 40 min with a 7-day interval. The color differences (ΔE₀₀), whiteness index for dentistry (WI_D), surface microhardness, roughness, microstructure, and composition were assessed.

The concentration and particle size of TiO₂ significantly affected ΔE₀₀ and ΔWI_D values, with the C1P100 group showing the greatest ΔE₀₀ values and C1P100, C3P100, and C5P100 groups showing the greatest ΔWI_D values (p < 0.05). No significant changes were observed in surface microhardness, roughness, microstructure or composition (p > 0.05).

Incorporating 1% TiO₂ with a particle size of 100 nm into HP constitutes an effective bleaching strategy to achieve desirable outcomes.