Immediate implant placement following 1-year treatment with oral versus intravenous bisphosphonates: a histomorphometric canine study on peri-implant bone.

OBJECTIVES: Bisphosphonates (BPs) are anti-resorptive medications with inhibitory effects on osteoclasts which decrease bone turnover. The present study aimed to assess the early effects of BPs on peri-implant bone.

MATERIALS AND METHODS: Twelve female mongrel dogs were assigned to one control and two experimental groups as follows: 12 months of oral alendronate (ALN, 3.5 mg/kg/week) or intravenous (IV) pamidronate (PAM, 1 mg/kg/week) for experimental groups. Following 8 weeks after implant insertion, the specimens were sacrificed, histological evaluation was performed, and C-terminal telopeptide of collagen I (CTx) analysis was performed on serums.

RESULTS: PAM demonstrated the greatest marginal bone level (MBL), 2.64 ± 0.48, followed by ALN and control, 2.5 ± 0.4 and 0.66 ± 0.5 respectively. The least bone-implant contact was observed in PAM group (%39 ± 0.03) while it was significantly greater in the control group (p < 0.05). PAM and ALN demonstrated < 10 CTx levels versus > 300 in controls.

CONCLUSION: It is assumed that long-term oral or IV BP therapy decreases marginal bone resorption and osseointegration. These changes were more accentuated in IV BP administration. CTx does not seem to be a precise predictor for bisphosphonate-related osteonecrosis of the jaw.

CLINICAL RELEVANCE: BPs impair peri-implant bone remodeling and this phenomena may be effective for reducing resorption at esthetic zone implants; however, decrease in osseointegration may be a concern for implant treatment in patients receiving BPs.