Tooth whitening 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, and then gels are placed on the teeth. A laser or plasma arc 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 (molds) of the mouth, and then has soft mouth trays made. The patient is fitted with the trays, and then is instructed to place a thin ribbon of the gel into the tray and wear while sleeping. Most whitening occurs in one to two weeks. In difficult cases, trays may need to be worn for up to six weeks. I have found that a combination of in-office and at-home systems works the best, and routinely achieve between 12 to 15 shades of whitening. The procedure is safe when monitored by a dentist, and does not damage the tooth in any way.
White fillings (resin, bonding) or porcelain crowns (caps) and bridges will not whiten significantly with either method. Some patients will experience minor tooth sensitivity during whitening procedures. The dentist can remedy this by alternating concentrated fluoride with the peroxide in the mouth trays.
The cost of in-office whitening is between $500 and $1100, the more expensive end when a laser is used. At-home systems cost between $400-$800. Store bought bleaching systems are not 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.