An Alaska brown bear at the Lake Superior Zoo in northeastern Minnesota has a new silver-colored canine tooth following a first-of-its-kind procedure for a bear. The hour-long procedure on 800-pound Tundra was undertaken by Dr. Grace Brown, a board-certified veterinary dentist who helped perform a root canal on the same tooth two years ago, and who plans to publish a paper on the procedure in the Journal of Veterinary Dentistry later this year. "This is the largest crown ever created in the world," she said. "It has to be published."