Effect of Dental Pigmentation Intensity on the Transenamel and Transdentinal Penetration of Hydrogen Peroxide

Abastract

This study aimed to evaluate the transenamel and transdentinal penetration of hydrogen peroxide (H₂0₂) applied to bovine teeth pigmented with black tea at different intensities. The following groups were formed DW: immersion in distilled water; BT100: immersion in an infusion of 1.6 g of black tea per 100 mL distilled water; BT10: immersion in an infusion of 1.6 g black tea per 10 mL distilled water. All groups were immersed for 6 days. To quantify the penetration of H₂0₂, the specimens were placed in artificial pulp chambers (APCs) and subjected to bleaching treatment with 38% H₂O₂ once per week for 3 weeks. After bleaching treatment, the acetate buffer solution of APCs with peroxidase enzyme was evaluated in a reflection spectrophotometer. The transenamel and transdentinal penetration of H₂O₂ and the L* values obtained at T1, T2 and T3 were subjected to Kruskal-Wallis and Friedman statistical tests. At T1, the H₂O₂ diffusion in DW was higher than that in BT100 and BT10. At the other evaluation times, the penetration values in BT100 and BT10 increased and remained similar. The L* values increased significantly in all groups at T1. At T2, the L* values were higher in DW, while the values in BT100 and BT10 were similar to each other. At the end of the experiment, BT10 showed the lowest L* values. The pigmentation level did not affect the penetration of H₂O₂ through the enamel and dentin and the bleaching agent effectively changed the color of the teeth.

Key Words:
pigmentation; dental bleaching; hydrogen peroxide