OBJECTIVE: To examine remodeling in bone supporting mini-implants by comparing a no drug (ND) group with a group that received a potent intravenous bisphosphonate in a canine model. MATERIALS AND METHODS: Twelve skeletally mature (2- to 3-year-old) male dogs were divided into two groups. Seven dogs were administered 0.1 mg/kg/mo of zoledronic acid (ZA) for 16 weeks, while five age-matched dogs received no drug. Two mini-implants (Tomas, Dentaurum, Newton, Pa) were placed unilaterally in the maxilla and mandible (4 mini-implants per animal × 12 = 48). Serial fluorescent bone labels were administered in vivo. Postmortem, the bone blocks containing the mini-implants were harvested and used for histomorphometric analyses at two regions of interest (adjacent: within 1 mm of interface; distant: 1-4 mm from the interface) supporting the mini-implant. Data were analyzed using mixed models. RESULTS: In general, the ZA group had a significantly lower bone formation rate than the ND group (P < .05) for all jaws/regions except for the adjacent region in the maxilla, P = .12. Despite the reduction, mean intracortical remodeling in the ZA group ranged from 35%-42% per year in the implant adjacent bone. This rate is substantially higher than that reported for noninjured sites in the jaw. CONCLUSIONS: Bone remodeling is typically elevated in implant supporting bone. After ZA administration, the healing response represented by elevated turnover in implant supporting bone was diminished but was not abolished.
OBJECTIVE: To examine remodeling in bone supporting mini-implants by comparing a no drug (ND) group with a group that received a potent intravenous bisphosphonate in a canine model. MATERIALS AND METHODS: Twelve skeletally mature (2- to 3-year-old) male dogs were divided into two groups. Seven dogs were administered 0.1 mg/kg/mo of zoledronic acid (ZA) for 16 weeks, while five age-matched dogs received no drug. Two mini-implants (Tomas, Dentaurum, Newton, Pa) were placed unilaterally in the maxilla and mandible (4 mini-implants per animal × 12 = 48). Serial fluorescent bone labels were administered in vivo. Postmortem, the bone blocks containing the mini-implants were harvested and used for histomorphometric analyses at two regions of interest (adjacent: within 1 mm of interface; distant: 1-4 mm from the interface) supporting the mini-implant. Data were analyzed using mixed models. RESULTS: In general, the ZA group had a significantly lower bone formation rate than the ND group (P < .05) for all jaws/regions except for the adjacent region in the maxilla, P = .12. Despite the reduction, mean intracortical remodeling in the ZA group ranged from 35%-42% per year in the implant adjacent bone. This rate is substantially higher than that reported for noninjured sites in the jaw. CONCLUSIONS: Bone remodeling is typically elevated in implant supporting bone. After ZA administration, the healing response represented by elevated turnover in implant supporting bone was diminished but was not abolished.