Does chewing ice harm teeth?

It certainly can.

It's not the fact that ice is cold that's the problem, said Dr. Thomas Kilgore, a professor of oral and maxillofacial surgery at the Boston University School of Dental Medicine. It's that ice cubes, like nuts, are so hard they can chip or crack teeth, especially teeth already weakened by large, old fillings.

"Nine times out of 10, you can chew ice and it won't have any effect," he said. But teeth can be structurally weakened by fillings, which makes them more susceptible to fracture from biting hard substances.

"If the filling has weakened the enamel, the tooth might crack."

And once you have a cracked tooth, whether because of chewing ice or something else, you may have to have a root canal or even need a crown or lose the tooth, said Dr. Jamie Wong, an assistant clinical professor of prosthodontics and operative dentistry at the Tufts University School of Dental Medicine.

So if you, like me, enjoy "eating" ice, let it melt in your mouth. But don't bite down.

JUDY FOREMAN

E-mail health questions to foreman@globe.com.