TiO₂ nanotubes incorporated into a glaze-coating ceramic: surface roughness, color, and antibiofilm activity

This study evaluated the surface roughness, color change, and antibacterial effect of a ceramic glaze enhanced with TiO₂ nanotubes (n-TiO₂). n-TiO₂ (0, 2, 2.5, and 5 wt%) was added to a ceramic glaze powder, applied to the surface of forty feldspathic ceramic specimens, and sintered. The surface roughness average (Ra) before glaze application (T0) and after glaze crystallization (T1) was measured using a profilometer. The colorimetric alteration was determined by CIEDE2000 (ΔE₀₀) and CIELab (ΔEab), and the whiteness index for dentistry (ΔW_ID). The antibacterial effect against S. mutans and S. sanguinis was evaluated (CFU/mL). Data were analyzed by two-way repeated-measures ANOVA, followed by the Bonferroni test (α = 0.05). No differences in ΔE_ab and ΔE₀₀ were observed among groups (p > 0.05), and ΔW_ID was only affected by 5% n-TiO₂. All groups surpassed the perception thresholds of 1.8 (ΔE₀₀) and 2.3 (ΔE_ab). At T0, no Ra differences were detected among groups (p > 0.05). In T1, Ra decreased (p < 005) compared to T0, but 5% n-TiO₂ increased roughness compared to the control group (without n-TiO₂). The incorporation of n-TiO₂ into the glaze powder did not impair bacteria adhesion, and no differences in biofilm formation were found among the concentrations (p < 0.05). The ceramic covered with a glaze containing 5% n-TiO₂ caused minimal interference in the color and roughness with no effect on biofilm formation.