Objectives: Regeneration of intrabony defects is a challenging target of periodontal therapy. The biologic rationale for regeneration not only is based on incorporating the regenerative material, but also takes into consideration the defect's inherent healing capacity. The present study was carried out to evaluate the efficacy of decortication or intramarrow penetration performed with demineralized freeze-dried bone allograft (DFDBA) in the management of intrabony defects. Method and materials: Forty chronic periodontitis (stage II and III periodontitis) patients having 40 intrabony defects were randomly assigned into test group (intrabony defect filled with DFDBA after intramarrow penetration along with open flap debridement [OFD+IMP+ DFDBA]) and control group (DFDBA along with open flap debridement [OFD+DFDBA]). Primary outcome measures included probing pocket depth, clinical attachment level, and percentage bone fill (%BF). All parameters were recorded at baseline, 6 months, and 9 months postsurgical follow-up. Results: Mean reduction in probing depth and gain in clinical attachment level was statistically significantly higher at the interdental defect site in the test group compared to the control group at 9 months follow-up (P = .02 and .04, respectively). In radiographic parameters, statistically significant improvements in defect depth and gain in defect area were found in the test group (P = .00 and .03, respectively). Statistically significant improvements in %BF and linear bone growth (P = .02 and .00, respectively) were also observed in the experimental group (39.47 ± 13.92% and 1.41 ± 0.54 mm) in comparison with the control group (19.29 ± 14.24%, 0.62 ± 0.49 mm). Conclusion: Addition of intramarrow penetration with DFDBA in surgical periodontal therapy may enhance the healing potential of periodontal intrabony defects, as observed by greater improvement in clinical and radiographic outcomes. Schlagwörter: bone graft, bone morphogenetic protein, growth factors, periodontal attachment loss, regeneration, wound healing