Objective: The aim of this study was to evaluate the radiographic outcomes following regenerative surgery using enamel matrix derivative (EMD) + freeze-dried bone allograft (FDBA). Method and Materials: In total, 74 two- or three-wall intrabony defects were treated by a combination of EMD+FDBA followed by supportive periodontal therapy (SPT) for a minimum of 2 years. Radiographs were taken at baseline and after the follow-up period. The measurements taken were: baseline defect angle, CEJ to the coronal part of the alveolar bone crest (CEJ-BC), CEJ to the apical part of the intrabony defect (CEJ- BD), the intrabony component of the defect (DL), and the defect angle between the lines CEJ-BC and CEJ-BD. Results: Baseline defect angles were divided into three groups: first group defect angle ≤ 22 degrees; second group 22 degrees to 36 degrees; and third group ≥ 36 degrees. A significant difference in DL following treatment was found in all groups (6.930 mm, 4.202 mm, and 2.073 mm respectively; P .01). The largest difference in DL was measured for the first group. A positive linear correlation was found between baseline values of the defect angle, CEJ-BD, CEJ-BC, and the later change in DL (P .01). Conclusion: The use of EMD+FDBA results in radiographic bone gain. Narrow defect angle and the depth of the intrabony component have significant positive correlation to radiographic bone gain. Keywords: defect angle, depth of the intrabony component, enamel matrix derivative, freeze-dried bone allograft, radiographic bone gain, regeneration