Tooth whitening (bleaching) involves the use of peroxide-based materials to whiten teeth. Most dentists use an in-office and/or at-home whitening system to achieve the desired results. Before tooth whitening, the patient must get all cavities filled, and the gums must be healthy.
The in-office systems use 35% hydrogen peroxide gels coupled with a high intensity light to whiten the teeth. The gums need to be protected with some systems. Gels are placed on the teeth. A light source activates the peroxide to oxidize stains on the tooth surface. In about an hour, the teeth become four to six shades lighter.
"At home" systems most often use 10 to 20% carbamine peroxide gels to oxidize stains. The dentist makes impressions (moulds) of the mouth, and then has soft mouth trays made. The patient is fitted with the trays, and is then shown how to place a thin ribbon of the gel into the tray which is then worn while sleeping. Most whitening occurs in one to two weeks. In difficult cases, trays may need to be worn for up to six weeks.
A combination of in-office and at-home systems works the best.
White fillings (resin, bonding) or porcelain crowns (caps) and bridges will not whiten significantly with either method. Some patients experience minor tooth sensitivity during whitening procedures.
Store bought bleaching systems are not however as effective as dentist-managed systems. Unsupervised use of store-bought bleaching systems can cause painful sensitivity to untreated dental cavities. The mouth trays are not custom made, which can cause gum irritation, and the peroxides are not as strong or effective.
