Enhancement of bone volume in guided bone augmentation by cell transplants derived from periosteum: an experimental study in rabbit calvarium bone.

Bone morphology is genetically encoded and it is usually difficult to change its structure without invasive surgery. We have tried to stimulate bone augmentation by a combination of guided bone regeneration techniques and cell transplants with collagen scaffolds for the suitable skeletal framework. In vitro-expanded tibia periosteum cells were used to promote osteogenesis with collagen scaffolds and titanium (Ti) or poly-L-lactic acid (PLLA) caps as barriers to create a space facing connective tissue under calvarium skin. This approach was assessed in the defective skull bone of a rabbit model. After a 12-week healing period, histomorphometric analyses were performed to determine the percentage of newly formed mineralized tissue in the cap. The mean percentage of newly formed mineralized tissue within the cap was 15.4%+/-3.99 for the Ti cap group, 15.5%+/-4 for the PLLA cap group, 6.19%+/-4.94 for the PLLA cap+collagen carrier group and 23.1%+/-23.1 for the PLLA+collagen carrier+cell transplants group. The cell transplant group showed a significantly higher value than other groups (P<0.05, Wilcoxon signed rank test, Mann-Whitney U-test). This approach of guided bone augmentation and cultured cell transplants with collagen carrier exhibited significantly greater morphogenesis of mineralized tissue than the control over a 12-week experimental period.