Histologic analysis of pulpal revascularization of autotransplanted immature teeth after removal of the original pulp tissue

The survival rate of replanted and autotransplanted teeth is mainly affected by the reaction of the pulp. Pulpal necrosis can cause periapical inflammation and inflammatory root resorption. The purpose of this study is to learn more about the pulpal changes in autotransplanted immature teeth whose pulp tissue was removed before transplantation. The experimental material consisted of 16 single-rooted teeth with open apices, from a beagle dog (3 months of age). At day 0, 4 teeth were extracted, the pulpal tissues were removed, and the teeth were then transplanted to their contralateral side. The same procedure was carried out on days 9, 16, and 23, each time for 4 single-rooted teeth. Longitudinal paraffin sections were made for histologic investigation. The results showed that, after 7 days, 2 of the 4 teeth had an ingrowth of new tissue over one fourth of their length. After 14 days, all 4 teeth had ingrowth ( : one fourth of the pulp chamber). At the 21-day observation, more than half of the pulp chambers of all teeth were filled, and, after 30 days, there was total ingrowth in 3 of the 4 teeth. This new tissue consisted of well-organized and well-vascularized connective tissue.