Hydrogen peroxide trans-dentin and trans-enamel penetration in cracked or microabrasioned enamel

Abstract

This study aims to verify trans-enamel and trans-dentinal 35% hydrogen peroxide penetration (HP) applied in different substrate conditions. Thus, 60 bovine incisors will be used in disc-shaped specimen involving enamel and dentin. The teeth will be divided into 3 groups (n = 20): GI-sound enamel, GII-teeth showing visible cracks in enamel, GIII- enamel will be submitted to microabrasion. Then, the specimens will be placed in an artificial pulp chamber containing buffer solution of acetate and receive bleaching treatment using 35% HP for 15 minutes. Subsequently, the surface will be cleaned using absorbent paper and sucking and new application will be performed until they complete three applications of 15 minutes, totalizing 45 minutes of exposure to the bleaching agent. The procedure will be repeated three times with one-week interval between sessions. To quantify the penetration of hydrogen peroxide, the acetate solution will be collected from inside the artificial pulp chamber and leucocristal violet dye solution and peroxidase will be added for the evaluation of optical density in a spectrophotometer. Readings will be performed before bleaching and after each whitening session. Data obtained will be submitted to the appropriate statistical model.