Abstract: Objective: To evaluate the treatment effectiveness of revascularization in necrotic immature teeth. Methods: Twenty-eight immature teeth which were diagnosed as periodontitis or pulp necrosis were recruited. X-ray was taken before revascularization. Clinical and radiographic data were collected. Statistical analysis was conducted to summarize the clinical factors which were related to root development. Results: The average follow-up time was 15.44 (12-30) months, among which 21 root canals achieved increase of root length, 20 root canals showed increase of dental wall thickness, and 4 root canals had calcification. Five types of responses were observed: type A, continued root maturation (apical foramen closure/narrow); type B, no significant continuation of root development with the root apex becoming closed; type C, severe calcification (obliteration); type D, a hard tissue barrier formed in the canal between the coronal MTA plug and the root apex; type E, there was no change compared before. The increase of root length was significantly different between the age and degree of bleeding, however, no significant different in the size of the root apical, the lesion area around the root apical, and the stage of root development. Conclusion: Pulp revascularizafion could be an effective treatment for immature permanent teeth, but its long-term effect still needs to be followedup

Key words: immature permanent teeth, pulp revascularization, apical periodontitis