A histomorphometric assessment of collagen-stabilized anorganic bovine bone mineral in maxillary sinus augmentation - a randomized controlled trial in sheep.

Abstract

To histomorphometrically compare the use of collagen-stabilized anorganic bovine bone (ABBM-C) (test) to anorganic bovine bone+autogenous bone (ABBM+AB) (control) in maxillary sinus augmentation. Nine sheep underwent bilateral sinus augmentation. Each sinus was randomized to receive either control or test bone graft. Three animals were sacrificed at 8weeks, and six animals were sacrificed at 16weeks post-grafting. The 18 sinuses were processed for histomorphometry, which assessed the area fraction of new bone (%NB), residual graft (%RG) and soft tissue components (% STM), as well as graft particle osseointegration (% OI), within three zones equally distributed from the augmented sinus floor. At week 16, a significant increase in %NB was evident across all three zones in the control group when compared to week 8. A significantly greater %NB was evident in the control group when compared to the test group in zones 2 (P<0.001) and 3 (P<0.001). There was a significant increase in %OI in week 16 when compared to week 8 across all three zones in the control group (P<0.001). %OI in the control group was significantly greater across all three zones when compared to the test group at week 16 (P<0.001). Zone was found to be a significant main effect (P<0.001) that was independent of time and treatment with decreasing %OI in distant zones. %RG did not significantly change with time for both groups. There was a significant reduction in %ST in week 16 when compared to week 8 across all three zones in the control group (P<0.001). %ST in the test group was significantly greater across all zones when compared to the control group at week 16 (P<0.001). Both groups exhibited very similar histomorphometric measurements in the zones proximal to the resident sinus wall. The % NB and % OI were greatest in the zones proximal to resident bony walls and gradually decreased as the distance from the proximal walls increased. There was greater % NB and % OI in the control group when compared to the test group in the distant zone.