Even the youngest schoolchildren in the United States know about George Washington's wooden teeth, so it's probably not a surprise to learn that teeth can be rebuilt and replaced. We've come a long way since the days of Washington, though, and now damaged or decayed teeth can be replaced with natural-looking implants, bridges and dentures. Researchers are also hard at work finding a way to rebuild teeth before they fully decay. Filling a cavity is just like patching a hole, but these researchers envision that one day, dentists will be able to insert a solution of chemicals that will cause the tooth to regenerate. Remineralized dentin and enamel will take the place of those gold or ceramic fillings, and your tooth would be good as new.