Lithium chloride (LiCl) is an activator of the canonical wnt signaling pathway. Previous studies indicated that systemic delivery of LiCl could enhance bone mass formation in vivo. The aim of this study was to investigate the effect of local injection of LiCl on bone regeneration in a rat periodontal defect model.
Method:
Fenestration defects were created in Sprague-Dawley rats on the buccal side of the mandible (n=4 per group). Local daily injection at the defect site was carried out using different concentrations of LiCl (10mM, 100mM, 1000mM diluted in 0.9% NaCl solution). Defects without any treatment and defects injected with saline alone were used as controls. Three weeks later, the mandible samples were collected and subjected to micro CT and histomorphometric analysis.
Result:
Three weeks after the treatment, new bone formation was observed in all of the groups. Bone coverage percentage of the defect area in each group was as follows: Blank, 3.75±4.15; NaCl, 5.75±5.63; 10mM LiCl, 10.75±8.61; 100mM LiCl, 20.75±5.63; 1000mM LiCl, 5.00±3.08, respectively. The animals in the 100mM LiCl group had the greatest amount of new bone fromation (P<0.05 compared to blank group), while injection with other concentrations of LiCl didn’t show significant difference of new bone formation compared with the control groups.
Conclusion:
Local injection of LiCl could enhance bone formation in a periodontal defect model. Further studies on the underlying mechanisms as well as methods for controlled release of LiCl in the local environment are needed.