Purpose: Intrabony defects pose a clinical challenge in treatment practice. Various regenerative techniques have been proposed for the treatment of residual defects. In particular, for intrabony defects or angular defects with a ≥ 3 mm of intrabony component, osseous grafts have been widely used. They have shown bone fill in the deepest portion of the defect. The purpose of this study is to evaluate coralline porous hydroxyapatite as a bone substitute in treatment of such defects. Methods: This present article reports a case series demonstrating the clinical and radiographic response to 3 different surgical procedures in the management of intrabony defects namely - open flap debridement (OFD), open flap debridement in conjunction with bone substitute coralline porous hydroxyapatite (OFD+CHA) and open flap debridement and placement of coralline porous hydroxyapatite and a resorbable collagen membrane (OFD+CHA+MEM). This follow-up also includes a surgical re-entry in the OFD+CHA+MEM site. Results: OFD, OFD+CHA, OFD+CHA+MEM, showed gain in clinical attachement and recession of 3mm and 1mm, 4mm and 1mm, 3mm and 0mm respectively. The radiographic bonefill as assessed by image analysis was seen to be 0.3mm, 6.9mm and 6.9mm for OFD, OFD+CHA & OFD+CHA+MEM respectively. On surgical re-entry at OFD+CHA+MEM, the wound site showed remarkable healing, the membrane had undergone complete resorption; the graft particles showed no mobility and were incorporated in the surrounding alveolar bone. Conclusion: To conclude, the 3 treatment modalities yielded results in accordance with the previous studies. The surgical re-entry procedure also revealed incorporation of graft particles in the surrounding healthy bone. Also the graft particles were stable and did not show any mobility. There was evidence of new bone formation at the base of the defect. These observations suggest that the coralline porous hydroxyapatite granules are compatible with the surrounding bone.