Guided tissue regeneration (GTR) is a common surgical procedure that helps regrow healthy bone and soft tissues. The result is that periodontal pockets are reduced in size and teeth will have better support. In a GTR procedure, your dentist places a thin material called a barrier over a periodontal defect below your gum. This barrier creates a space in which your healthy tissue can grow. Some GTR barriers are absorbed by your body while others are not. A barrier that is not absorbed requires you to return for a second surgery, while a barrier that is absorbed needs only one surgery.