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TEETH WHITENING

Recently, the American public has become very conscious of the cosmetic appearance of teeth, perceiving whiter and brighter as a desirable condition. To meet this need, a significant number of teeth whitening systems have been commercialized either via a dental professional or through direct marketing and pharmacy/supermarket distribution. The whole subject can be quite confusing so let us visit the various tooth whitening systems to see if it can become a little less so. The first step is to classify the tooth whitening systems into two categories: in-officed and take-home.

In-office systems can be further defined as those "requiring" a light source and those that do not. The ones that do not require light activation consist of pastes and gels of varying percentages of hydrogen peroxide that are placed on the teeth for 20 to 30 minutes (the gums have to be protected with some sort of a barrier to keep them from becoming irritated). This procedure is repeated one or two more times resulting in whiter teeth in the 60 to 90 minutes of exposure time. However, the degree of whitening can usually be increased if some sort of take-home whitening gel are used subsequent to the in-office treatments. The fee for this type of whitening usually runs from $600 to $1200; any take-home gels are usually extra. The second category of in-office whitening systems uses a light source which, supposedly, enhances the whitening effect of the painted-on peroxide gels. The light source can be from a yellow halogen bulb, a sapphire plasma arc light, a light emitting diode (LED) or a multi-purpose laser. Many of these systems are franchised and have national advertising campaigns promising a change in lightness of up to 10 or more shades with just one in-office visit. The controversy here is that there is no proof that the light actually contributes to the whitening process and is used only to justify the large fee that is required for the "dental chair rental" (my term). Dr. Gorden Christensen, Director of Clinical Research Associates which is the most respected scientific research facility in dentistry, says that, "Use of lights according to manufacturer's directions did not improve lightening for any system (we) tested." Dr. Harold Heymenn, Professor and Graduate Program Director at the University of North Carolina College of Dentistry, concluded that multiple appointments are required to achieve significant whitening and that the most important factor in whitening is the concentration of the bleaching gel and not the light! Adding to the controversy is the fact that all of these systems recommend the use of take-home products which, again, requires additional time and expense over and above the in-office treatment (by the way, in-office bleaching with a light source can cost as much as $2000).

There are several take-home whitening systems. The products advertised on the infomercials consist of stock trays and whitening gels with varying percentages of peroxide gels as bleaching agents. Take-home whitening treatment fabricated in the dental office, on the other hand, consist of customized trays and bleaching gels that are more highly concentrated. The problem with one-fits-all stock trays is two-fold. First, because of the extra space around the edges of the trays, a lot of the bleach will run out into the mouth-the patient has to use more to start with and it doesn't really taste that great; also, the saliva will quickly dilute the bleach leading to a poorer result. Another concern about stock trays is that more of the bleach will come in contact with the gums which can and will lead to inflammation and soreness. Customized trays are tightly fitted over the teeth and trimmed back at the gum line; much less bleach is lost and there is much less saliva penetration inside of the tray and thus less dilution of the bleaching gel. There is also much less of chance that the gums will be exposed to the bleach for an extended period of time. Another interesting take-home system utilizes whitening strips (Crest). These things actually work if a patient is only interested in bleaching the front teeth. These strips have the same peroxide compounds in them as any other system and are placed over the teeth just like a Band Aid strip; thirty minutes twice a day for a couple of weeks. These can be purchase in many dental offices and these professional strips not only have a higher concentration of peroxide in them, there are quite a few more strips in the kit. Paint-on products and whitening tooth pastes do not work so don't spend the money on them.

Here are some things to consider before you commit to any whitening procedure:
- If you have any white fillings in your front teeth, be aware that they will not bleach out and may have to be re-done because they may look like dark spots against your newly-whitened teeth.
- A frequent side effect of any bleaching system is tooth sensitivity; this is a transient problem that goes away within a few days.
- Yellow and brown intrinsic stains bleach the best; grey teeth, expecially tetracycline-stained teeth, require a much longer period of time to get a desired effect (sometimes months) and results in lighter grey teeth which look better than the original dark grey although not snowy white.
- The teeth color may or may not relapse as time passes; if it does, it is easy to give yourself a one or two day "booster" using your bleaching trays (or new strips) and this is usually something you have to to once or, at most, twice a year.

Now I have to say that there are white teeth and then there are "too white teeth". A row of Chicklets (referred to as "Hollywood white") does not look natural on most people so don't get carried away. If your teeth are already a shade that is the whiteness of the top two or three on my (the Lumin) shade guide, you should probably save your money.
posted by Steve at 12:40 PM