Laser Bleaching May Help Stubborn Stains
April 22, 2009

by Nancy Volkers
InteliHealth News Service

INTELIHEALTH - A new type of bleaching may help whiten stubborn tooth stains, a study says.

Researchers from Iran did the study. They tested a type of whitening called photodynamic bleaching. They used it on teeth that had been discolored by tetracycline, an antibiotic.

Tetracycline is not recommended for use in pregnant women or in children whose teeth are developing (until age 16). This drug can affect the development of tooth enamel, causing dark stains.

Researchers tested the whitening method on 90 teeth in 23 adults. Photodynamic bleaching uses a whitening gel and a laser. The gel is put on the teeth, and the laser's light activates the gel. Each tooth was exposed to the light for 2 minutes total.

The treatment lightened about 80% of the teeth.

Currently, lasers can remove some tooth stains, but they usually work best with stains that come from outside, such as those from food or coffee. Tetracycline stains are "built in" to the tooth as it develops. They are much more difficult to remove. Dentists usually cover teeth stained by tetracycline with veneers -- thin sheets of tooth-colored material.

The study appears in the April 15 issue of the journal Photomedicine and Laser Surgery.