Objective: The purpose was to qualitatively and quantitatively compare the bone formation and graft resorption of two different bone substitutes used in both orthopedic and oral surgery, with autogenous bone as a positive control.
Materials and methods: Three standardized bone defects were prepared in both mandibular angles of 12 adult minipigs. The defects were grafted with either autograft, anorganic bovine bone (ABB), or synthetic β-tricalcium phosphate (β-TCP). Sacrifice was performed after 1, 2, 4, and 8 weeks for histologic and histomorphometric analysis.
Results: At 2 weeks, more new bone formation was seen in defects filled with autograft than with ABB (P∼0.0005) and β-TCP (P∼0.002). After 4 weeks, there was no significant difference between β-TCP and the two other materials. Defects grafted with ABB still exhibited less bone formation as compared with autograft (P∼0.004). At 8 weeks, more bone formation was observed in defects grafted with autograft (P∼0.003) and β-TCP (P∼0.00004) than with ABB. No difference could be demonstrated between β-TCP and autograft. β-TCP resorbed almost completely over 8 weeks, whereas ABB remained stable.
Conclusion: Both bone substitutes seemed to decelerate bone regeneration in the early healing phase as compared with autograft. All defects ultimately regenerated with newly formed bone and a developing bone marrow. The grafting materials showed complete osseous integration. Both bone substitutes may have a place in reconstructive surgery where different clinical indications require differences in biodegradability.