To evaluate through a randomized, blind clinical study the effectiveness of two conventional bleaching agents modified by the incorporation of ozone gas on the degree of dental bleaching and color stability. Methodology: Forty-two teeth were selected with endodontic treatment and a degree of dental saturation (GS) equal to or greater than A2 and divided into 2 groups (n=21 teeth: PNaS: Sodium perborate + saline solution and PNaOZ: Sodium perborate + ozone sunflower oil with 16 ppm. Color GS was evaluated at the beginning of treatment and 7 days after the end of treatment, with the aid of Vita classical color scale. The statistical analysis of the color GS was performed by the Wilcoxon test, and the number of sessions by the Shapiro-Wilk test followed by the Mann-Whitney test, for correlation between GS and the number of clinical sessions, spearman correlation was performed. Resulted: There was a statistically significant difference between the initial (G1 = 15.0 ± 2.00 and G2 = 16.00 ± 1.00) and final (G1 = 5.00 ± 6.00 and G2 = 3 ± 3.00) GS values and PNaOZ had a greater color variation between the final and initial color. The number of clinical sessions was statistically lower for PNaOZ. No significant differences were found between the number of sessions and the GS. Conclusion: Adding ozone to sodium perborate accelerated dental bleaching, thus reducing the number of clinical sessions.