Characterization and effectiveness of a violet LED light for in-office whitening

Area of Science:

• Dental materials science
• Biophotonics
• Cosmetic dentistry

Background:

• Violet LED light (V-LED) devices are marketed for tooth whitening.
• The efficacy and light characteristics of V-LED devices require thorough scientific evaluation.
• Comparison with established whitening agents like hydrogen peroxide (HP) is crucial.

Purpose of the Study:

• To characterize the beam profile and irradiance of a V-LED tooth whitening device.
• To evaluate the V-LED device's tooth whitening efficacy on stained enamel compared to 40% HP.
• To assess light transmission through bovine enamel.

Main Methods:

• V-LED beam profile and irradiance were measured using a laser beam-profiler and spectral radiometer.
• Bovine enamel blocks stained with black tea, cigarette smoke, or unstained were treated with V-LED or 40% HP.
• Color change parameters (ΔE₀₀) and light transmittance were measured.

Main Results:

• V-LED exhibited heterogeneous beam distribution and decreased irradiance (25-50%) during exposure.
• V-LED showed significantly lower whitening efficacy (ΔE₀₀) than HP on unstained and black tea-stained enamel.
• Light transmittance through 1-mm enamel was reduced by approximately 98%.

Conclusions:

• V-LED irradiance is inconsistent and diminishes with distance and usage.
• V-LED demonstrates inferior whitening performance compared to HP for certain stains.
• The findings highlight limitations for V-LED clinical application in tooth whitening.