Background: The aim of this study was to evaluate the effect of two different concentrations of titanium dioxide nano particles TiO2NP on the color and surface roughness of enamel surface.
Material and methods: 20 bovine anterior teeth were selected. Each tooth was divided into two equal halves and distributed to two groups A and B. Group A: one half is subjected to bleaching agent (AI) and the other half to bleaching agent mixed with 5% TiO2NP (AII). Group B: one half is subjected to bleaching agent (BI) and the other half to bleaching agent mixed with 10% TiO2NP (BII). Surface roughness (Ra) and color changes were evaluated using stereomicroscope and spectrophotometer. Results: There was no statistically significant difference in the roughness Ra between all bleaching groups at (p=5981>0.05). 10% concentration of TiO2NP group represented the lowest mean color value while there was no statistically significant difference in bleaching only groups and 5% concentration TiO2NP group using Pair-wise Tukey post-hoc (p>0.05). Conclusions: Titanium oxide nano particles had an influence on the efficiency of bleaching agent without jeopardizing enamel surface roughness.