Teeth whitening is also commonly referred to as tooth bleaching, mainly because the active ingredient in most products is hydrogen peroxide (or products that release hydrogen peroxide when mixed with water or air).
What’s Hydrogen Peroxide Teeth Whitening
Hydrogen peroxide(HP) is a mild antiseptic used on the skin to prevent infection of minor cuts, scrapes, and burns. It may also be used as a mouth rinse to help remove mucus or to relieve minor mouth irritation.
Different countries have different regulations on the allowable concentration of hydrogen peroxide released by products. In Australia, only dentists can provide products that release more than 6% hydrogen peroxide. In New Zealand, non-dentists can use up to 12% hydrogen peroxide to whiten teeth. In the UK, it is illegal for anyone other than a dentist to use a concentration higher than 0.1%.
Dentists in Australia can use high levels of hydrogen peroxide. Some in-chair whitening systems use 35% hydrogen peroxide. At this concentration, hydrogen peroxide can effectively penetrate deep into the enamel structure. The weaker concentration only acts on the surface of tooth enamel.
Although hydrogen peroxide is the active ingredient in most whitening products, some tooth whitening gels contain carbamide peroxide or sodium perborate. Both of these agents decompose to release hydrogen peroxide.
Difference Between Different HP Treatments
So, what is the difference between teeth whitening services provided by dentists, whitening products provided by cosmetics companies, and DIY whitening products?
The boundaries between these categories are becoming blurred. Many dentists now provide teeth whitening care and then take them home and make them available to consumers. Non-dentists also provide “in-chair” whitening care, which usually requires light-activated products. Both methods work by releasing hydrogen peroxide, but in-chair systems tend to use products that release higher levels of hydrogen peroxide, especially those used by dentists.
Laboratory-based studies have shown that whitening in the chair by dentists increases the strength of tooth enamel, making it more resistant to acid erosion. In contrast, home whitening has been shown to increase the loss of mineral content in tooth enamel, which may cause tooth weakness over time.
Researchers suggest that the home system should be used under the supervision of a dentist. Overuse of whitening products purchased over the counter may cause long-term damage to teeth.
Another major difference is that dentists will take tooth molds and use it to make whitening trays. This ensures that the treatment only touches the teeth and not the gums. It is important that hydrogen peroxide does not come into contact with the gums for a long time, as this can cause burns.
Many shops that offer teeth whitening claim to use “peroxide-free” products. Consumers should ask what these actually contain. The product may not contain peroxide before use, but will release hydrogen peroxide when activated. Products that truly do not contain or release hydrogen peroxide are unlikely to be very effective in whitening teeth.
Tooth enamel bleached by DIY whitening products may be easily damaged by scrub toothpaste. Long-term use of household whitening products may weaken the enamel surface, making it more susceptible to acid damage or abrasion.
Once the teeth are white, you do not need to continue whitening, but the effect will gradually disappear. The whitening effect usually lasts for 6-12 months, depending on tooth brushing and eating habits.