DINA GIESLER: The best way to describe a crown is it's a cap that we put on a tooth, and it's probably the best procedure we have to save a tooth. A patient needs a crown when the tooth has been ...

As if Komodo dragons weren’t formidable enough, it turns out that their razor-sharp teeth are capped with iron for longevity. Several mammals also have iron deposits in their teeth, but none as ...