Marrow-derived mesenchymal stem cells-directed bone regeneration in the dog mandible: a comparison between biphasic calcium phosphate and natural bone mineral.

OBJECTIVE

This study was designed to compare mesenchymal stem cell (MSC)-based alveolar bone regeneration in biphasic bone substitutes and natural bone mineral in a canine full-thickness alveolar defect model.

MATERIALS AND METHODS

MSCs were isolated from bone marrow aspirates and culture expanded through 3 successive subcultures. The bone differentiation potential of third passage cells was evaluated and confirmed in vitro before cells were used in the transplantation experiment. Undifferentiated cells were then incubated with 3 x 3 x 3 mm(3) hydroxyapatite/beta-tricalcium phosphate (HA/TCP) matrices (Kasios, Lanauguet, France) and 1- to 2-mm Bio-Oss spongiosa (Geistlich Biomaterials, Osteohealth, Switzerland), which is a natural bovine bone mineral (NBM). Kasios/cell, Kasios alone, Bio-Oss/cell, and Bio-Oss alone were implanted in masseter muscle and 4 cylindrical (10-mm diameter) through-and-through bilateral mandibular body defects in 4 mongrel dogs. Histomorphometric analysis was performed 6 weeks after insertion of the scaffold loaded with MSCs.

RESULTS

H&E staining of the decalcified scaffold and scanning electron microscopy demonstrated large MSC coverage of the HA/TCP and Bio-Oss. Cell-loaded Kasios matrices showed the greatest amount of the bone regeneration among the groups in both the muscle (29.11%) and the bone specimens (65.78%). Cell-free biphasic scaffold revealed 44.9% bone fill in bone defects and 23.55% in muscle specimen, and Bio-Oss alone matrices had the least amount of new bone formation: 36.84% and 24.16% in bone and muscle specimens respectively. Kasios loaded with MSCs demonstrated more bone regeneration than Bio-Oss/cell but there was no significant statistical difference (P > .05).

CONCLUSIONS

New biphasic synthetic bone substitutes may offer better conditions for bone regeneration than traditional bone substitute in combination with MSCs. They remained in the defect and contributed to bone regeneration.