Effect of local vs. systemic bisphosphonate delivery on dental implant fixation in a model of osteonecrosis of the jaw

Locally applied bisphosphonates may improve the fixation of metal implants in bone. however,systemic bisphosphonate treatment is associated with a risk of osteonecrosis of the jaw (onj). we hypothesized that local delivery of bisphosphonate from the implant surface improves the fixation of dental implants without complications in a setting where systemic treatment induces onj. forty rats were randomly allocated to 4 groups of 10. all groups received a titanium implant inserted in an extraction socket. group i received the implants only. group ii received dexamethasone (0.5 mg/kg). group iii received dexamethasone as above plus alendronate (200 μg/kg). group iv received zoledronate-coated implants and dexamethasone as above. the animals were sacrificed 2 weeks after tooth extraction. all 10 animals with systemic alendronate treatment developed large onj-like changes,while all with local treatment were completely healed. implant removal torque was higher for the bisphosphonate-coated implants compared with the other groups (p < 0.03 for each comparison). micro-computed tomography of the maxilla showed more bone loss in the systemic alendronate group compared with groups receiving local treatment (p = 0.001). local bisphosphonate treatment appears to improve implant fixation in a setting where systemic treatment caused onj. © international & american associations for dental research 2013.