Tooth whitening, often called bleaching, is one of the more discussed subjects in the modern dental office. The process of whitening teeth, or lightening the normal shade of the teeth, has become commonplace and since the patents have expired on the primary chemical used to whiten teeth, the cost has declined significantly over the past several years. The fact that it is easy to do, can be rather quickly done, and with a significantly reduced cost, makes this procedure one of the more highly sought-after dental treatments.
The general color of teeth is primarily yellow, but there are also teeth which are blue, pink, brown and gray. A few folks are born with beautiful and naturally white teeth. The gray shade is the most difficult to whiten or bleach. It can be done but usually takes a bit longer. In addition, some teeth may have dental fluorosis, caused by too much fluoride in the water, usually from well water. This results in a blotchy brown stained tooth. Other stains may come from too much tetracycline as a child during the developmental stages of the teeth, or from tobacco, tea, coffee, wine and iron. Other than tetracycline, these are superficial stains and may be polished away. Excessive brushing can thin the enamel over the years, allowing the darker dentinal layer to show through the enamel thereby making the tooth darker in color the harder one brushes. It also pushes the gums up or down the tooth exposing the roots of the teeth which are darker in color. Heavy brushing, or tooth brush abrasion is never good.
You also need to know that permanent teeth are darker in shade than deciduous (baby) teeth and there is always some concern about this during the mixed dentition stage since the baby teeth are often very white.
The chemical used to whiten teeth is carbamide peroxide in solutions of approximately 11% up to about 40%. The stronger the solution the quicker the whitening. But there is one caveat. The stronger the solution the more sensitivity affects the teeth and gums. When this chemical mixes with saliva, it changes to hydrogen peroxide and is diluted. A younger person, 16 years old and below, has greater sensitivity, so they are usually encouraged to wait until older or to proceed very, very slowly.
The chemical may be applied in three primary ways. Clear strips, custom made trays, and zoom whitening. Clear strips often take much longer as the solution is much, much weaker. Custom made trays is the take-home, wear-while-you-sleep treatment, and is quite effective. One can easily go two nights, skip a night, and then go two more. This creates very minimal sensitivity.
Another plus to this method is that the “mold” can be kept and the same tray can be used two to three years later for touch-up whitening. The zoom whitening is under consideration for its effectiveness due to the expense and the number of visits required.
It must be remembered, and this should be pointed out to you by your dentist, that this bleaching/whitening technique will not change the shade or color of your existing porcelain fillings, porcelain crowns, laminates, porcelain fillings, or bonding.
Most dentists will have before-and-after photos of this procedure with their actual patients and will be most helpful in giving you advice. Also, it is advisable to do the maxillary (upper) arch first so that you can easily see the difference the whitening has made. Should you do both arches at the same time, the change will be less apparent to you.
American Dental Association-Life Member, Fellow of Academy of General Dentistry, American Academy of Implant Dentistry