[Study on periodontal responses on the compression side during early tooth movement into alveolar defect regenerated...

To explore periodontal responses on the compression side during early tooth movement into alveolar defect regenerated by bone marrow mesenchymal stem cells (BMSCs) and porous granulated beta-tricalcium phosphate（β-TCP） scaffolds.

Thirty New Zealand rabbits were used to establish bilateral mandibular defective alveolar bone model by extracting the mandibular first molars and expanding the sockets. The right mandibular alveolar defects were filled with a construct of β-TCP scaffolds combined with BMSCs as experimental group. The left alveolar defects were repaired by β-TCP scaffolds alone as control group. Eight weeks later, 6 rabbits were sacrificed to evaluate osteogenesis effect. The other rabbits were loaded orthodontic force to move the bilateral second molars forward for 4 weeks. Six rabbits in each group were sacrificed at 1, 2, 3, and 4 week after orthodontic tooth movement (OTM). The distance of OTM was measured, and the status of periodontal tissues was observed by H-E staining. The number of osteoclasts on the compression side of tooth was counted by tartrate-resistant acid phosphatase histochemistry. The results were compared between groups using SPSS 19.0 software package.

After 8 weeks of bone grafting, the osteogenesis effect of the experimental group was better than the control group. The OTM distance in the experimental area was higher than that in the control area. At 2, 3 and 4 week of OTM, the number of osteoclasts in the experimental group was significantly higher than that in the control group.

A tissue-engineered complex with β-TCP scaffolds and BMSCs could well repair the alveolar bone defect. When the adjacent tooth moved into regenerated area, the new periodontal tissue had an active response, promoting to accelerate tooth movement.