Non-Contained Maxillary Ridge Defects Augmented with 50:50 Synthetic–Autogenous and Xenogeneic–Autogenous Composite Grafts: Four Cases with CBCT Volumetry

Synthetic calcium phosphates have been tested in randomised trials of sinus augmentation and ridge preservation but rarely in ridge augmentation. To our knowledge, the augmented volume of biphasic calcium phosphate (BCP) mixed with autogenous bone has not been measured clinically in non-contained ridge defects. We grafted four such maxillary defects with BCP (RESORBA Synthetic Bone, hydroxyapatite/β-tricalcium phosphate 60/40; S1, S2) or porcine xenogeneic mineral (RESORBA Xenogenic Bone Graft; X1, X2), each mixed 50:50 with scraper-harvested autogenous chips, under a native collagen membrane (PARASORB RESODONT Forte). Cone-beam computed tomography volumetry gave the net radiodense volume (new bone and residual graft) in a fixed 10 × 10 mm window, with measurement envelopes over analysis choices. All four sites healed uneventfully and received implants, with the graft (S1, X1) or at re-entry (S2, X2), S2 with 2 mm of buccal hard tissue despite loose particles outside the contour. All were uneventful for 13–65 months after grafting, apart from one resolved sinus tract in X1. Volumes (mm3, envelopes in brackets) were 99.7 (91.8–112.3) in S1 and 137.0 (127.6–150.8) in X1, their envelopes overlapping before the post hoc changes, and 95.4 (82.3–99.5) in S2 and 267.1 (261.4–272.3) in X2, apart before and after them. As each volume difference is also one between patients and sites, none is attributed to the substitute.