Despite the legends, George Washington did not have wooden teeth. In fact, the set of teeth he used in 1789, the year he took his oath of office in New York City, are now on display at Mount Vernon and a picture is available on the Mount Vernon web site.
Washington reportedly had only one of his original teeth left by 1789. John Greenwood made dentures for Washington. The picture shows a denture made of hippopotamus ivory with real human teeth attached by brass screws. The denture, which was anchored on the one remaining tooth in Washington’s mouth, has a hole which fit snugly around the one tooth.
All this sounds uncomfortable. I am especially sympathetic this week as I had a tooth removed on Wednesday and am now wearing a temporary denture for a couple of weeks. I find it most uncomfortable but at least I don't have to suffer with hippopotamus ivory and brass screws attaching someone else's teeth. I'll receive a new dental implant in a couple of weeks, an option not available to George.
You can see a picture of George Washington's dentures at http://www.mountvernon.org/calendar/index.cfm/fuseaction/event/calID/207/