
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 dentin, the tooth’s core material, to show through. During routine chewing, the 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 acquire 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.
In-office Whitening
Significant color change in a short period of time is the major benefit of in-office whitening. This protocol involves
the carefully controlled use of a relatively high-concentration peroxide gel, applied to the teeth by the dentist
or trained technician after the gums have been protected with a paint-on rubber dam. Generally, the peroxide remains
on the teeth for several 15 to 20 minute intervals that add up to an hour (at most). Those with particularly stubborn
staining may be advised to return for one or more additional bleaching sessions, or are asked to continue with a home-use
whitening system.