Co-doped titanium dioxide nanoparticles decrease the cytotoxicity of experimental hydrogen peroxide gels for...

Area of Science:

• Dental materials science
• Biomaterials engineering
• Photochemistry

Background:

• Hydrogen peroxide (HP) gels are widely used for tooth whitening.
• Higher concentrations (e.g., 35%) offer greater efficacy but pose risks of cytotoxicity.
• Novel formulations aim to enhance efficacy while minimizing adverse effects.

Purpose of the Study:

• To evaluate the efficacy and cytotoxicity of experimental 6% and 35% HP gels (HP6, HP35) with co-doped titanium dioxide nanoparticles (NP) and violet LED light (LT).
• To assess the impact of NP and LT on HP diffusion, color change, and cellular response.

Main Methods:

• Bovine enamel-dentin disks were bleached with various HP formulations (HP6, HP35, commercial HP35) with or without NP and LT.
• Color change (ΔE₀₀) and whiteness index (ΔWI_D) were measured.
• Cytotoxicity was assessed using MDPC-23 cells exposed to gel extracts, measuring viability, oxidative stress, and morphology.

Main Results:

• HP6 with NP and LT (HP6+NP+LT) showed significant color and whiteness improvements, comparable to HP35 groups.
• HP6+NP+LT exhibited the lowest HP diffusion and highest cell viability among bleached groups.
• HP35 formulations demonstrated the lowest cell viability, indicating higher cytotoxicity.

Conclusions:

• Incorporating NP and LT into HP6 gel significantly enhances whitening efficacy and reduces cytotoxicity compared to HP6 alone.
• This approach offers a promising alternative to higher HP concentrations, potentially improving esthetic outcomes and reducing tooth sensitivity.