| Most of us start out with sparkling white teeth, thanks to their porcelain-like enamel surface. Composed of microscopic crystalline rods, tooth enamel is designed to protect the teeth from the effects of chewing, gnashing, trauma and acid attacks caused by sugar. But over the years enamel is worn down, becoming more transparent and permitting the yellow color of dentine — the tooth’s core material — to show through. During routine chewing, dentin remains intact while millions of micro-cracks occur in the enamel. It is these cracks, as well as the spaces between the crystalline enamel rods, that gradually fill up with stains and debris. As a result, the teeth eventually develop a dull, lackluster appearance. Teeth whitening removes the stains and debris, leaving the enamel cracks open and exposed. Some of the cracks are quickly re-mineralized by saliva, while others are filled up again with organic debris. Virtually everyone who opts for this cosmetic treatment will see moderate to substantial improvement in the brightness and whiteness of their smile.
There are two categories of staining as it relates to the teeth: extrinsic staining and intrinsic staining.
1. Extrinsic Stains
Extrinsic Stains are those that appear on the surface of the teeth as a result of exposure to dark-colored beverages, foods and tobacco, and routine wear and tear. Superficial extrinsic stains are minor and can be removed with brushing and prophylactic dental cleaning. Stubborn extrinsic stains can be removed with more involved efforts, like teeth bleaching. Persistent extrinsic stains can penetrate into the dentin and become ingrained if they are not dealt with early.
2. Intrinsic stains
Intrinsic stains are those that form on the interior of teeth. Intrinsic stains result from trauma, aging, exposure to minerals (like tetracycline) during tooth formation and/or excessive ingestion of fluoride. In the past, it was thought that intrinsic stains were too resistant to be corrected by bleaching. Today, cosmetic dentistry experts believe that even deep-set intrinsic stains can be removed with supervised take-home teeth whitening that is maintained over a matter of months or even a year.
Two major teeth whitening options are available today. Both rely on varying concentrations of peroxide and varying application times.
1. In-Office Whitening |
Teeth whitening treatments are considered to be safe when procedures are followed as directed. However, there are certain risks associated with bleaching that you should be aware of:
1. Sensitivity
Bleaching can cause a temporary increase in sensitivity to temperature, pressure and touch. Some individuals experience spontaneous shooting pains down the middle of their front teeth. Whitening sensitivity usually lasts no longer than a day or two.
2. Gum irritation
Over half of those who use peroxide whiteners experience some degree of gum irritation resulting from the bleach concentration or from contact with the whitening trays. Such irritation typically lasts up to several days, dissipating after bleaching has stopped or the peroxide concentration lowered.
3. Restored teeth
Restorations such as bonding, dental crowns or porcelain veneers are not affected by bleach and therefore maintain their default color while the surrounding teeth are whitened.
1. At-home follow-up or maintenance whitening — implemented immediately or performed as infrequently as once a year.
2. Avoiding dark-colored foods and beverages for at least a week after whitening.
3. Whenever possible, sipping dark-colored beverages with a straw.
4. Practicing excellent oral hygiene — brushing and flossing after meals and at bedtime. |
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Maintaining your whiter smile |
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