Histologic and histomorphometric results of three bone graft substitutes after sinus augmentation in humans

The aim of this study was to compare the histological behavior of three bone graft materials placed in human. The comparison was made among Bio-Oss® (BO), Engipore® (EP), and PepGen P-15® (P-15). Five biopsies for each group of biomaterial, retrieved 6 months after sinus lift augmentation, were analyzed. The investigation was carried out using light microscope (LM), scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and circularly polarized light microscope (CPLM). Under LM, the amount of newly formed bone was significantly higher in BO than P-15 (P < .05), while the amount of residual graft material was significantly higher in P-15 than BO (P < .05). The extension of marrow spaces was significantly higher in EP than both BO and P-15 (P < .05). SEM-EDS analysis showed a Ca/P ratio of 1.8 for BO, 2.2 for EP, and 1.5 for P-15. Under CPLM, BO showed no significant difference for transverse (18.4 ± 2.7%) and longitudinal (16.3 ± 1.8%) bone collagen fibers (P = .195); EP showed a significant difference between transverse (4 ± 0.7%) and longitudinal (7.6 ± 2.5%) bone collagen fibers (P = .015); finally, P-15 showed no significant difference for transverse (3.8 ± 1.6%) and longitudinal (4.9 ± 1.2%) bone collagen fibers (P = .279). No investigated biomaterial was completely resorbed, but all the residual particles demonstrated a close bone integration to form a hybrid tissue. BO particles appeared perfectly osseointegrated in the trabecular bone. EP showed a tendency to concentrate the bone apposition into the microporosities; P-15 particles appeared bridged by newly formed bone trabeculae.