The Effects of Bisphosphonate Administration on Teeth Development and Growth of the Jaw Bones in Neonatal Rats: Histological and Immunohistochemical Study

Background: Bisphosphonates are potent inhibitors of osteoclastic bone resorption and widely used for the treatment of osteoporosis, and osteogenesis imperfecta in children. Clinical and experimental studies have demonstrated that Bisphosphonates delay or inhibit tooth eruption. This study tries to focus on the effect of bisphosphonate on teeth development and jaw bones growth. Materials and methods: The present study includes 65 neonatal rats during lactation period from 15 Albino Wister rats mother. Alendronate (one type of Bisphosphonates) was administrated orally (15 mg/kg) into 10 pregnant rats two times a week, while other 5 rats regard as control. Then the neonatal rats sacrificed in I, 6, 11, 16 and 21 days. The lower first molar were examined histologically and immunohistochemical for amelogenin expression. Biochemical serum analysis for calcium and alkaline phosphatase level were down for 11, 16 and 21days group. All histological, immunohistochemical, and biochemical results are compare with their controls. Results: The histological results illustrate retardation in tooth and root development, impairment in maturation of enamel and retardation in tooth eruption of the first molar tooth germ in alendronate treated neonatal rats than their controls. Also immunoreactivity for amelogenin at early stages of tooth development was somewhat more intense in experimental group than that in their controls .Moreover, calcium and alkaline phosphatase serum levels in experimental rats are less than that of their controls. Conclusion: This study concludes that treatment with alendronate during tooth development has the potential to inhibit tooth eruption, impair tooth formation, may induce some types of dental abnormalities, and increase the bone trabecule thickness by decreasing osteoclastic activity.