According to this study 1, hydrogen peroxide is not absorbed by the skin, but can cause systemic toxicity when inhaled or ingested. I am not entirely sure how often hydrogen peroxide is inhaled or ingested when used in dentistry for the treatment of gingivitis, periodontitis or tooth whitening. And could not find any studies that indicate such data.
A new theory on vitiligo suggest it is caused by oxidative stress in association with high levels of hydrogen peroxide 2 3. Preferred sites of vitiligo vulgaris are face, hands, feet, genitals, and generally around body openings and in areas where the skin is irritated by friction, abrasion, pressure from blemishes (Koebner phenomenon).
Can the use of Hydrogen Peroxide in dentistry worsen the oxidative stress in patches of facial vitiligo vulgaris?