A case report is presented on transplantation of a left third molar to replace a right second molar lost due to large furcation perforation. Two weeks after surgery, a reentry surgical procedure was performed on the furcation defect of the second molar to remove membrane and retrieve proliferating periodontal tissue. The left third molar and proliferating periodontal tissue were then transplanted into the bone defect of the right second molar. Radiographically, the transplanted tooth showed no root resorption over a 3-year period. The results indicate that teeth replanted with proliferating periodontal tissue have a favorable long-term prognosis.