Abstract: Objective： To compare the clinical treatment efficiency of platelet-rich fibrin (PRF) assisted revascularization and traditional revascularization in immature permanent teeth. Methods: Eighteen nonvital immature permanent teeth of sixteen patients which were diagnosed as necrotic pulpitis with (or without) periapical inflammations were treated with PRF assisted revascularization. Twenty-two teeth non-vital immature permanent teeth of twenty patients which were diagnosed as necrotic pulpitis with (or without) periapical inflammations were treated with traditional revascularization. All the cases were accorded with inclusive criteria and were treated at Pediatric Dentistry of Peking University School and Hospital of Stomatology. The cases were followed up clinically and radiographically at regular intervals. Clinical examinations and periapical radiographs were recorded and analyzed. Clinical success rate was evaluated based on the clinical and radiographic findings. The changes of root length, dentine wall thickness and apical foramen width of the teeth from the two groups were measured and compared according to the preoperative and by recalling the periapical radiographs. Results: The cases were followed up for 6－16 months. Clinically, totally 17 out of the 18 teeth in PRF group and 21 out of the 22 teeth in traditional group were asymptomatic with no sensitivity to percussion or palpation. PRF group tended to be more effective than traditional group clinically without significant differences (P=0.446). Radiographically, 15 out of the 18 teeth in PRF group and 15 out of the 22 teeth in traditional group displayed that the roots developed, showing that root length and dentine wall thickness increased and apical foramen closed. There was a marked difference in dentine wall thickening in PRF group in comparison with traditional group (P=0.039). However, the changes of root length increasing (P=0.411) and apical foramen width closure (P=0.737) were comparable in both groups. The result in electric pulp test (P=0.517), root canal calcification (P=0.324) and crown discolor (P=0.386) were also comparable in the two groups. Conclusion: PRF assisted revascularization and traditional revascularization in nonvital immature permanent teeth which were diagnosed as necrotic pulpitis with (or without) periapical inflammations resulted in similar clinical outcomes. Both methods showed good prognosis. PRF revascularization seemed to have better effect on dentine wall thickening than traditional method.

Key words: Pulp revascularization, Regeneration, Platelet-rich fibrin, Immature teeth, Children patient