Microabrasion effect on enamel susceptibility to penetration of hydrogen peroxide: an experimental and computational...

To evaluate in vitro transenamel/transdentinal of penetration of H₂O₂ after microabrasive. Computational models were performed to verify peroxide penetration and evaluate if geometric modifications could affect in vitro results. Enamel/dentin blocks from bovine incisors were prepared and randomly divided into groups (n = 15) according with abrasive (35% phosphoric acid and pumice or 6.6% hydrochloric acid and silica) and bleaching agents (16% carbamide peroxide and 35% H₂O₂). From artificial pulp chambers, the H₂O₂ concentration was measured and SEM was used for surface morphology. Numerical models were performed (Abaqus® v6.12) modifying slightly enamel/dentin thickness based on experimental data. All groups presented H₂O₂ penetration, although no significant difference was noted between the control and experimental groups (p > 0.05). The numerical analysis demonstrated the role of dental tissue thickness in the H₂O₂ penetration. Microabrasion is recommended as its association with bleaching procedures and small modifications in thicknesses of enamel/dentin can cause substantial changes in HP penetration. Such diffusion aspect is clinically relevant for the bleaching procedures since very thin enamel could present more peroxide propagation through dental tissues.