Dear Dr. Mady: 
I have recently lost weight, have changed my hair colour and am feeling great about myself. Now I am in search of whiter teeth. There are so many different products and advertisements out there and I don’t know where to begin. Any advice? Anne in Newark N.J.

Dear Lynn, 
I experience your indecisiveness often with my own patients and I always ask the same questions and always give the same advice. How quick do you want them whiter and how long do you want them to stay white?

In today’s world, there is increasing market for tooth whiteners from individuals like you. How to determine the type that is best suited to you is the big problem for someone who is not a dentist or who does not work in the field of dentistry. If you listen to companies marketing their products, you would think every tooth-whitening product in the world works.

Often brushing, flossing and regular trips to your dentist for cleanings is just not enough to get your teeth as pearly as you would like. We all know that nothing lights up a presence like a bright white smile, but I am going to give you some things to take into consideration before running out to your drugstore or dentist that will help you make a better decision and save you money.

The belief that all teeth are white is a fallacy. Most adult teeth are shades of grey and yellow or both. On top of this, teeth darken with age. Also contributing to this is the fact that the layer under the enamel, known as dentin, is much more yellow than enamel. Years of brushing and wear and tear thins the enamel and allows this dentin to shadow through easier.

Eating habits are a factor. If you are an individual who drinks an abundance of tea, coffee, red wine or acidic juices, your enamel over time can become damaged or darkened. If you tend to eat foods that contain tomato sauces, mustard, ketchup and similar things, this does not help the situation. Lastly if you smoke, you are not just staining your teeth, but shortening your life expectancy.

The most common ingredient used in teeth whiteners that are sold over the counter or used in a dentist’s office is hydrogen peroxide. Peroxide at different strengths has the ability to penetrate below the outer surface of the teeth’s enamel and allows oxygen to enter below the surface also. This allows the tooth to whiten below the surface in addition and it does not change the structure of the teeth or harm them. The degree of whitening changes with each individual and it is important to know that tooth coloured resin fillings (commonly used today) and porcelain crowns, bridges or veneers will not whiten with any technique!

The main options available today that seem to work at different success levels are, over-the-counter whitening strips, take-home whitening kits that require the use of whitening trays and in-office systems that involve using light to activate the peroxide so that better and faster results can be achieved.

The whitening strips consist of thin gel-coated strips that are placed against the teeth for anywhere from 5 to 30 minutes for seven to ten days (depending on the brand). These tend not to adapt as well to the different sizes and shapes of adjacent teeth especially by the gum line. They are not inexpensive and they seem to work on some people, especially younger individuals, but the effects don’t always last long. The peroxide has to be weaker because the strips always touch the gums.

With the take-home kits that your dentist prescribes, impressions are taken of your mouth and custom trays are fabricated that cover the entire surface of the teeth and not the gums. The individual applies the gel into the trays at night for seven to ten days and sleeps with them. Some types are worn morning and afternoon for the same number of days for thirty to sixty minutes. The peroxide is slightly stronger and causes temporary sensitivity in some patients. But it seems to be decreasing as the products evolve.

The last and most successful type appears to be the in-office whitening system. The peroxide is stronger and light activated. For this procedure to be performed the right way, a protective coating is placed and hardened on the gums and the peroxide is applied and then subsequently light activated for fifteen minutes, three times. Trays are also made to wear in the future if you stain them again and a gel is given to take home. That gel should bring them right back to the way they were when the procedure was completed. In the long run, this type is the most economical. An example of this type of system is the “ZOOM” whitening system that is seen on television’s “Extreme Makeover”.

I guess it is all a matter of how long you want the whitening procedure to take, how much money you want to spend and how quick a result you want. Any FREE laser whitening advertisements that you see on the internet or in many cities usually involve a LED activated gel that is placed on the teeth with no gum and lip protection. The procedure takes fifteen minutes and rarely produces any results that last. If you are interested in in-office whitening, call the provider and inquire about the specific procedure and exactly how it is done. Also consult with your dentist before seeking whitening treatment anywhere other than a dental health facility.

Any questions for Dr. Mady can be e-mailed to drmady@drmady.com and also visit his blog at www.dentalden.com (dental education network)

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This column is reprinted with the permission of the author and The Windsor Star. “Ask the Dentist” is written by Windsor dentist (and ECDS member), Dr. David Mady Jr.. The column appears the first Thursday of each month in the Windsor Star. Readers with questions can write to “Ask The Dentist”, c/o The Windsor Star, 167 Ferry St., Windsor Ontario, N9A 4M5