Does Light Enhance Whitening?

Researchers report conflicting results when comparing tooth whitening with and without the use of an intensifying light. Some show that the light helps to whiten teeth while others show it has no effect. Researchers in the division of dental hygiene at Ohio State University in Columbus, Ohio, compared whitening with and without the use of the Zoom light from Discus Dental, a division of Philips. The study included 49 patients whose teeth were whitened using a 25 percent hydrogen peroxide gel, Discus Zoom 2.
 
 For each patient, the gingiva was isolated using a light-cured resin dam, Discus Liquidam. The whitening gel was placed on the maxillary and mandibular anterior teeth at a thickness of 2mm. The gel was placed on the right or left half (depending on random assignment) and the sodium arc light positioned directly in front of the mouth for 15 minutes. The gel was then removed with high volume evacuation and new gel was applied. This process was repeated for three 15-minute whitening sessions. The opposite sides of the arches were then treated with three 15-minute whitening sessions without the light.
 
Patients were seen at one week and two weeks to take the shade and get their feedback on whitening and sensitivity. At one week, the maxillary teeth whitened using the light were found to be a lighter shade. At two weeks, there was no difference. Patients saw no difference at any time. Very little sensitivity was reported.
 
Clinical Implications: When whitening with 25 percent hydrogen peroxide the light will only produce a lighter tooth shade for one week. ■

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