Methods: Nine experimental materials were provided by the manufacturer (Formulation was not provided). Forty-eight rabbits were utilized in the study. A three cm anteroposterior incision was made along the central region of the calvaria, and the soft tissue was reflected exposing the cranial bones. An eight mm trephine bur at 1100 rpm under saline irrigation was utilized to create two bilateral (anterior and posterior) defects through the thickness of the calvaria, and the nine experimental materials plus control (no material) were placed in the defects. Half of the animals were sacrificed at four weeks and the other half at eight weeks after surgery. The calvaria were then retrieved by sharp dissection and bone, biomaterial, and soft tissue were assessed by Micro-CT and quantified by computer software.
Results: Immediate post-surgical evaluation and routine animal care did not show any signs of inflammation or infection for any subject throughout the course of the study. Micro-CT 3D reconstructions showed that all experimental materials were osteoconductive and biocompatible, and that higher degrees of bone formation along with lower amounts of grafting material remaining in the defect were observed at eight weeks compared to four weeks for all experimental materials. Varied degrees of bone formation were observed for different materials, however defect margin bridging was often observed compared to control defects that presented bone formation restricted to areas close to the defect margins.
Conclusions: All grafting materials evaluated were biocompatible and osteoconductive, and different amounts of bone formation and biomaterial degradation were observed for different formulations. A full physical and chemical characterization is desirable to relate materials structure to bone response is under way, as well as histologic evaluation.
Keywords: Animal, Biomaterials and Bone
See more of: Dental Materials 5: Biocompatibility and Biologic Effects