Does zoledronate therapy make mandibular bone susceptible to fracture? A radiographical and biomechanical study in rats

Injury. 2018 Oct;49(10):1746-1749. doi: 10.1016/j.injury.2018.07.006. Epub 2018 Jul 6.

Abstract

Introduction: The aim of this study was to evaluate the effect of zoledronate therapy on susceptibility of mandibular bone to fracture in rats.

Methods: Fifty rats were randomly allocated to two groups of 25 animals. The rats in group Z received monthly intravenous infusion of 0.06 mg/kg zoledronate for 6 months. The rats in the group C were injected with an equal volume of saline in the same manner. A month after the last zoledronate/saline administration, all 50 rats were euthanized. Using a cone beam computed tomography, the cortical thickness of inferior border of mandible and the mandibular bone mineral density were calculated, and using a three-point bending test, the peak load failure and the ultimate stress of mandibular bone were determined.

Results: The mean mandibular inferior cortical bone thickness and the mean bone mineral density were significantly larger in zoledronate-treated rats (0.30 ± 0.02 mm and 1045.00 ± 185.79, respectively) compared to control rats (0.21 ± 0.01 mm and 878.66 ± 166.53, respectively). The peak load and the ultimate stress were lower in the zoledronate-treated hemimandibles (84.61 ± 33.62 N and 1.76 ± 0.72 MPa, respectively) compared to the control hemimandibles (98.36 ± 16.5 9 N and 2.03 ± 0.44 MPa, respectively).

Conclusion: Zoledronate therapy reduced the mechanical strength of the mandibles, implying an increased risk of mandibular fracture in rats.

Keywords: Bisphosphonate; Bone; Fracture; Mandible; Zoledronate.

MeSH terms

  • Animals
  • Biomechanical Phenomena
  • Bone Density / drug effects*
  • Bone Density Conservation Agents / administration & dosage*
  • Bone Density Conservation Agents / adverse effects
  • Bone Density Conservation Agents / pharmacology
  • Cone-Beam Computed Tomography
  • Disease Models, Animal
  • Male
  • Mandible / diagnostic imaging
  • Mandible / drug effects*
  • Mandible / pathology
  • Mandibular Fractures
  • Random Allocation
  • Rats
  • Rats, Wistar
  • Stress, Mechanical
  • Zoledronic Acid / administration & dosage*
  • Zoledronic Acid / adverse effects
  • Zoledronic Acid / pharmacology

Substances

  • Bone Density Conservation Agents
  • Zoledronic Acid