Background: Marginal pedicle periosteum (MPP) has been used as a rigid membrane in guided tissue regeneration (GTR) for osseous defects. The present study aims to study the effect of space provision by an alloplastic graft material in bone defect area (BDA) reduction of 2-wall defects.

Methods: Twenty interproximal intrabony 2-wall defects in healthy non-smoking patients with chronic periodontitis were randomly divided in control (group 1, periosteum alone) and experimental (group 2, periosteum with alloplastic graft material) groups. Measurements of probing depth (PD), clinical attachment level (CAL), and radiographic BDA were done at the baseline and 6-month postoperative evaluations.

Results: The 6-month postoperative assessment showed clinical and radiographic improvements with PD reduction, CAL gain, and changes in BDA in both groups, which was statistically significant compared with baseline (P <0.05). However, BDA reduction was statistically greater in group 2 (48.88% ± 18.61%) compared with group 1 (14.08% ± 12.97%) at the 6-month follow-up (P = 0.009).

Conclusion: Within the limitations of this study, it can be concluded that space provision by an alloplastic graft material increases the  regenerative potential of MPP as a GTR membrane and results in increased defect fill.