The present research was conducted to explore the infra bony pockets in chronic and generalized aggressive periodontitis from the radiographic point of view using CBCT. A total of 150 infrabony pockets were included in the study obtained from 33 patients (20 females and 13 males). The defects were classified into 2 equal groups, 75 defects in chronic periodontitis (Group I), 75 in the generalized aggressive periodontitis (Group II). The Simplant program was used to measure the infrabony pocket depth, the vertical bone loss, the defect angulation, the bone density at the base of the defect, the defect volume. Also the percentage of furcation involvement and presence of calculus were recorded. Results showed higher rates of alveolar bone loss, wider defect angles, decreased bone density apical to the defects, larger defect volumes and more furcation involvement in Group II compared to Group I with statistically significant differences. On the other hand Group I showed significant percentage of calculus formation when compared to Group II. So it can be concluded that the multifactorial risk factors associated with generalized aggressive periodontics resulted in too much higher rates of periodontal destruction when compared to the chronic periodontitis group. Also the local factors play an important role in the pathogenesis of chronic periodontitis, but they are of little importance in generalized aggressive forms. The Simplant software technologies enabled measuring the defect volume which can aid in the estimation of the proper graft volume before surgery.