Over-the-counter strips, gels, and tray systems
Medicated adhesive strips are one of the most popular over-the-counter whitening systems available today. Numerous clinical trials have shown that these strips, which usually contain hydrogen peroxide, can effectively remove intrinsic stains and make teeth six to seven shades brighter, according to Dr. Kugel. "We've done tons of studies, and if it didn't work for someone, I would predict that the patient wasn't using it right," he says. In one study, Kugel found that Crest Whitestrips are comparable to an in-office whitening treatment. Over-the-counter paint-on gels and tray-and-gel systems, which employ hydrogen peroxide or carbamide peroxide, can also whiten teeth, if used correctly. However, each system has its downsides: Strips may be hard to keep in place; paint-on gels can be difficult to use and may become diluted with saliva; and trays, which aren't custom made, sometimes fit poorly, allowing the gel to seep out or saliva to seep in. "They may work effectively, [but] because they are not dentist monitored, many of them won't work for everyone," says Dr. Plotino.