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

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.

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.

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.

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.