Teeth Whitener Products May Weaken Tooth Enamel

Friday, October 09, 2009 by: David Gutierrez, staff writer
Tags: teeth whiteners, health news, Natural News

(NaturalNews) Home-use whitening products may deplete teeth's protective enamel and also reduce its ability to resist and recover from normal wear-and-tear, according to a study conducted by researchers from the Ohio State University College of Dentistry in Columbus, and published in the Journal of Dentistry.

Researchers tested five different tooth whitening products by using each one on 10 different tooth samples as directed, for either 10 or 21 days. They then used a nanometer scale to measure any changes to hardness or elasticity on the scale of one billionth of a meter and compared these findings with tests of five tooth samples that had not been exposed to whitening products.

While some of the tooth whiteners were over-the-counter products and others could only be acquired by prescription, all are intended to be used at home. Two of the products were whitening strips, while three were nightguard home bleach systems.

They found that teeth treated with whitening products had lost between 1.2 and 2 nanometers of thickness, along with between 6 and 18.8 percent of their elasticity.

Elasticity is a measure of the enamel's ability to recover from an applied force. Enamel is the hardest substance in the human body, and is typically able to repair itself over time.

Untreated teeth lost only 0.4 nanometers of thickness, and decreases in elasticity were also significantly less than those observed in the treated teeth.

Because enamel is naturally translucent, it typically reflects the yellow color of the dentin beneath it. Teeth whitening products use either hydrogen peroxide or carbamide peroxide to bleach the organic pigment of the enamel, rendering it white. This effect functions because the free radicals in the peroxide attack the organic pigment molecules, denaturing them.

Known side effects of tooth bleaching include gum irritation and tooth sensitivity, and products are already marketed to reduce these symptoms of tooth and gum damage.

Sources for this story include: www.reuters.com.