Evaluation of osseous healing in induced mandibular defects grafted with biphasic calcium phosphate doped with silver and zirconium nanoparticles: An experimental study in dogs

Objective

Evaluation of the osteoconductive p otential of the nanocomposite tricalcium phosphate/hydroxyapatite (TCP/HA) bi-doped with zirconium (Zr) and silver (Ag) ions versus TCP/HA & 4AgTCP/HA in induced defects.

Methods

Fifteen dogs were divided into four groups in 12 weeks duration before euthanasia: 1-control, 2- TCP/HA, 3- TCP/HA doped with Ag and 4-TCP/HA bi-doped with Ag & Zr groups. Four surgically created defects were randomly allocated in each animal on the left and right mandibular sides, three defects were grafted with mentioned alloplasts and one empty control. Clinical, radiographic, and histological evaluations were performed for the newly formed bone.

Results

Clinical results revealed no infection or inflammatory conditions. All graft groups revealed a significant increase (P<0.05) in mature bone mean density versus controls. TCP/HA bidoped with Ag and Zr group elucidated a highly significant increase (P <0.01) in mature bone density compared to other groups while the TCP/HA was statistically insignificant (P > 0.05) compared to the Ag-doped TCP/HA. The bactericidal action of both Zr and Ag nanoparticles was evident by antibacterial testing.

Conclusion

Bi-doping of TCP/HA with Ag and Zr has a synergistic osteoconductive effect to enhance bone formation as an excellent modality for defective bone reconstruction. Histomorphometric investigation clarified that Ag and Zr doped TCP/HA stimulated osteogenesis and bone remodeling as compared to un-doped TCP/HA. Therefore, this nanocomposite has promising clinical significance in grafting maxillofacial bone defects for optimal healing compared to un-doped TCP/HA. Moreover, Zr and Ag nanoparticles are effective bactericidal materials with optimal biological safety on the animals.