Characterization of the Nanostructure of Collagen Fibers Following the Application of Dilute Hydrogen Peroxide used in Dental Whitening Treatments

Abstract

This work aims to understand the effect of dilute hydrogen peroxide (H₂O₂) solutions, used in dental whitening treatments, on the nanostructure of type I collagen fibers. Using this approach, collagen fibers were exposed to 1%, 3% and 5% H₂O₂ solutions, and the changes in their nanostructure were analyzed by combining topographical and phase-shift atomic force microscopy (T-AFM and PS-AFM) results with circular dichroism (CD) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The combination of these techniques demonstrates that after exposure to 1 to 5% peroxide solutions, collagen fibers form agglomerates while the rupture of intramolecular bonds occurs, leading to collagen secondary structure loss and degradation. These results show for the first time that even dilute H₂O₂ solutions have a significant effect on collagen at the nanostructural level.

Keywords:

• Atomic force microscopy
• collagen
• dentin
• hydrogen peroxide
• nanostructure

Disclosure statement

The authors declare that there are no conflicts of interest.

Additional information

Funding

The authors acknowledge Fundação para a Ciência e a Tecnologia for funding through the projects 3D-DentalPrint 02/SAICT/2016/023940, UID/QUI/00100/2019 (CQE), UID/BIM/04585/2019 (CiiEM), UID/CTM/04540/2019 (CeFEMA) and UID/EMS/50022/2019 (IDMEC-LAETA).