Local Injection of 1,25-dihydroxyvitamin D3 Enhanced Bone Formation for Tooth Stabilization After Experimental Tooth Movement in Rats

The present investigation evaluated the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on alveolar bone formation during tooth movement in rats. Orthodontic elastics were inserted between the maxillary first and second molars on bilateral sides in male rats. 1,25(OH)2D3 was injected locally, at the concentration of 10(-10) M, once every 3 days in the submucosal palatal area of the root bifurcation of the molar on the right side. Histomorphometric analysis revealed that tooth movement without application of 1,25(OH)2D3 decreased the mineral appositional rate (MAR) on the compression area at 7 days. Repeated injections of 1,25(OH)2D3 in the orthodontically treated animals distinctly stimulated alveolar bone formation on the mesial side at 14 days. There was a significant increase in MAR associated with elevated osteoblast surface (Ob.S/BS) value on the tension surface. These findings suggest that local application of 1,25(OH)2D3 enhances the reestablishment of supporting tissue, especially alveolar bone of teeth, after orthodontic treatment.