Dr Yan-Fang Ren and colleagues of the Eastman Institute for Oral Health at the University of Rochester Medical Centre in New York set out to examine the ill effects of over-the-counter teeth whitening products, which contain six per cent hydrogen peroxide.

Instead the researchers found that orange juice was so acidic that its ill-effects on tooth enamel were far worse than teeth whitening agents. The acid in the juice cut into the hardness of enamel and made it rough rendering it vulnerable to attack by bacteria that cause tooth decay.

“Most soft drinks, including sodas and fruit juices, are acidic in nature,” lead researcher Dr Ren said. “Our studies demonstrated that the orange juice, as an example, can potentially cause significant erosion of teeth.”

Researchers used a new focus-variation vertical scanning microscope that enabled them to view the surface irregularities on enamel in extensive detail. They report that the acid in orange juice decreased enamel hardness by an astonishing 84 percent.

Dr Ren explained that acidity of fruit juices always pose a risk for enamel, but prior to this study there were no comparisons of juice and teeth whitening products as far as enamel erosion was concerned. “We do not yet have an effective tool to avert the erosive effects, although there are early indications that higher levels of fluoride may help slow down the erosion," he added.

The details of the study appear in the Journal of Dentistry.

Consumers must be aware of the acid content of fruit juices that are consumed as a part of daily diet. It is recommended that they drink the juice quickly since enamel damage will be extensive if the juice is in contact with teeth for a longer time. Furthermore using fluoride-based toothpaste may also help reduce tooth erosion.