Hydrogen Peroxide Might Bleach Natural Dentin by Oxidizing Phosphoprotein.

Area of Science:

• Biochemistry
• Biomaterials Science
• Dental Research

Background:

• Tooth whitening mechanisms are not fully understood.
• Fluorescence in dentin is linked to proteins at the organic-inorganic interface.
• Dentin phosphoprotein (DPP) is a candidate for dentin's fluorescence.

Purpose of the Study:

• To investigate if dentin phosphoprotein (DPP) is the source of dentin fluorescence.
• To determine if bleaching agents, specifically hydrogen peroxide (HP), whiten teeth by oxidizing DPP.

Main Methods:

• Fifty-six dentin specimens were treated with distilled water, HP, EDTA, or acetic acid.
• Measurements included organic/inorganic components, fluorescence, and color (ΔE) before and after treatment.
• DPP solution treated with HP was analyzed for UV absorbance.

Main Results:

• EDTA removal of DPP significantly reduced fluorescence and whitened dentin.
• Acetic acid did not affect DPP, fluorescence, or color.
• HP oxidized DPP, decreasing fluorescence and whitening dentin, with reduced UV absorbance in DPP solution.

Conclusions:

• Dentin phosphoprotein (DPP) is responsible for the fluorescent properties of dentin.
• Hydrogen peroxide (HP) likely bleaches dentin by oxidizing aromatic amino acids within DPP.
• Findings enhance understanding of tooth bleaching mechanisms and dentin fluorescence.