Direct dentin bleaching: Would it be possible?

Area of Science:

• Dental Materials Science
• Biophotonics
• Aesthetic Dentistry

Background:

• Dental bleaching is a common aesthetic procedure.
• LED technology is increasingly explored for dental applications.
• Understanding the efficacy of different light sources on various stains is crucial.

Purpose of the Study:

• To evaluate the in vitro effectiveness of violet LED light on dentin pigmented by different agents.
• To analyze chromatic alteration, bleaching effect, and temperature variations.
• To compare the response of various stains to violet LED bleaching.

Main Methods:

• 60 bovine dentin discs were pigmented with natural, black tea, coffee, red wine, or equine blood.
• A violet LED bleaching session was performed.
• Chromatic alteration (∆E, ∆E00, ∆a, ∆b, ∆L), whitening index (WID), and temperature were measured.
• Statistical analysis included one-way ANOVA and Tukey's post-test.

Main Results:

• Violet LED light induced chromatic changes and a bleaching effect across tested groups.
• Soluble coffee and natural pigmentation showed the most positive response.
• Equine blood pigmentation exhibited resistance to treatment and the highest temperature increase.
• Red wine pigmentation showed reduced whitening index compared to other groups.

Conclusions:

• Violet LED light demonstrates a bleaching effect on pigmented dentin in vitro.
• The efficacy of violet LED bleaching varies depending on the staining agent.
• Blood and red wine stains present challenges for violet LED bleaching, with blood also causing significant temperature rise.