Application of Enamel Matrix Derivative for Tooth Transplantation and Replantation.

OBJECTIVE: The purpose of this study was to clarify the effects of enamel matrix proteins on the regeneration of periodontal ligament (PDL), during transplantation and replantation therapy. MATERIALS AND METHODS: [Exp 1] The crown and root apex of extracted dog teeth were removed and the remaining root separated longitudinally. Two-thirds of crown-side PDL and cementum were removed. Prepared teeth were covered with propyleneglycol alginate (PGA) both with and without enamel matrix derivative (EMD) and cultured for 0-14 days. The outgrowth length of the tooth was measured and histological observation done. [Exp 2] The incisal teeth of adult dogs were extracted and 2/3 of crown side PDL and cementum removed. Prepared teeth were treated with PGA containing EMD (EMD group). No tooth treatment was done in the control group. Following PGA treatment, teeth were replanted. The animals were sacrificed at 2 and 4 weeks after replantation and histological observation performed. RESULTS: [Exp 1] The outgrowth length of the EMD group was longer than that of the other groups. The width of proliferated cell layer on the tooth in the EMD group was thicker. [Exp 2] Ankylosis surface of the EMD group was smaller than that of the control group. In the control group, the region of ankylosis increased longitudinally. In the EMD group, the newly-formed cementum was predominantly cellular cementum. CONCLUSION: The results suggested that enamel matrix protein enhance the regeneration of PDL and prevent tooth ankylosis in transplantation and replantation therapy.