In vitro performance of violet LED and argon plasma with oxygen on dentin bleaching.

Area of Science:

• Biomaterials science
• Dental materials research
• Surface science

Background:

• Dentin's chromatic alteration impacts aesthetics.
• Current bleaching agents can compromise dentin's integrity.
• Novel methods for dentin bleaching are needed.

Purpose of the Study:

• To evaluate violet LED and argon plasma (with/without oxygen) effects on dentin.
• Assess chromatic alteration, whitening, temperature, wettability, surface energy, and bond strength.
• Compare these novel treatments against 35% hydrogen peroxide.

Main Methods:

• In vitro study on 100 bovine dentin discs.
• Groups: Control, Argon Plasma (APL), APL+Oxygen (APL+O), Violet LED, 35% Hydrogen Peroxide (HP).
• Evaluated chromatic alteration, bleaching index, temperature, contact angle, surface energy, total free interaction energy, and bond strength after thermal cycling.

Main Results:

• APL+O showed bleaching efficacy comparable to HP.
• Violet LED increased temperature and created a hydrophobic surface.
• APL+O exhibited lower contact angles and higher total free interaction energy.
• APL and APL+O bond strength surpassed only the control group; HP had the lowest bond strength.
• No treatment prevented bond strength loss.

Conclusions:

• Plasma treatments are effective for dentin bleaching.
• Violet LED and argon plasma alter dentin surface properties.
• None of the evaluated therapies effectively preserved dentin bond strength post-bleaching.