CareOne Anticavity Mouth Wash

CareOne Anticavity Mouthwash claims that it “restores enamel.”

It is not possible to truly rebuild or restore tooth enamel, which, once lost, is lost forever.

While it is not possible to regrow lost enamel, it is possible to help protect remaining enamel from further erosion and to reinforce weak spots. If you’re concerned about enamel erosion, look for a good fluoride toothpaste or mouthwash, which will help make the tooth’s surface more resistant to acid.

As for one specific fluoride formula being better than another, however, the evidence seems to be shaky. According to the Wall Street Journal:

Scientists say any well-designed fluoride toothpaste will make enamel more acid resistant. The enamel-strengthening claims on the label are ‘a marketing gimmick,’ says Dr. Featherstone, who has done paid consulting for a number of toothpaste makers. Consumers should choose a toothpaste with a taste they like, as they’ll use it more, he says.

In order to prevent enamel erosion in the first place, people should limit the amount of sugary and acidic foods and drinks they consume.

Several other mouthwashes make similar claims. See also:
ACT Restoring Mouthwash
Crest ProHealth Anticavity Fluoride Rinse
Listerine Total Care Anticavity Mouth Wash