Attributes of Bio-Oss® and Moa-Bone® graft materials in a pilot study using the sheep maxillary sinus model

Abstract

Background and Objective: The aim of this pilot study was to characterize surface morphology and to evaluate resorption and osseous healing of two deproteinated bovine bone graft materials after sinus grafting in a large animal model. Material and Methods: Surfaces of a novel particulate bovine bone graft, Moa-Bone® were compared with Bio-Oss® using scanning electron microscopy. Six sheep then had maxillary sinus grafting bilaterally, covered with BioGide®. Grafted maxillae were harvested after 4, 6 and 12 weeks. Healing was described for half of each site using resin-embedded ground sections. For the other half, paraffin-embedded sections were examined using tartrate resistant acid phosphatase staining for osteoclast activity, runt-related transcription factor2 immunohistochemistry for pre-osteoblasts and osteoblasts and proliferating cell nuclear antigen for proliferative cells. Results: Moa-Bone® had a smoother, more porous fibrous structure with minimal globular particles compared with Bio-Oss®. After 4 weeks, woven bone formed on both grafts and the Moa-Bone® particles also showed signs of resorption. After 12 weeks, Moa-Bone® continued to be resorbed, however Bio-Oss® did not; both grafts were surrounded by maturing lamellar bone. Moa-Bone® was associated with earlier evidence of runt-related transcription factor 2-positive cells. Moa-Bone® but not Bio-Oss® was associated with strong tartrate resistant acid phosphatase-positive osteoclasts on the graft surface within resorption lacunae at both 4 and 6 weeks post-grafting. Conclusion: Both materials supported osseous healing and maturation without inflammation. Moa-Bone® showed marked osteoclast activity after 4 and 6 weeks and demonstrated positive attributes for grafting, if complete remodeling of the graft within the site is desired. Further optimization of Moa-Bone® for maxillofacial applications is warranted.