The use of dental implants for support of replacement teeth has been demonstrated to be safe and effective, and can dramatically improve perceived oral health and quality of life for patients unhappy with conventional prosthesis. The protracted treatment time required for implant use, however, can be costly in time and direct costs associated with treatment. The long-term objective of this research is to investigate whether dental implants can be placed into function earlier than currently prescribed without detriment to their overall survival. Therefore, the goal of this investigation is to determine the feasibility of early restoration of occlusal function of dental implants in a population of adult micro-minipigs. The project will provide baseline information for the design of additional, as well as human clinical trials for testing the safety and efficacy of early loading of dental implants. Twelve adult Panepinto micro-minipigs will have three premolar teeth on each side of the mandibular arch extracted and allowed to heal for two months. After healing, four HA-coated screw-shaped implants will be inserted into carefully prepared bone sites ensuring adequate fixation. The anterior implant, which will be the unloaded control implant will be placed 10.00 mm posterior to the mandibular canine and will remain submerged. The remaining three implants will be placed 10 mm from both the control implant and the first molar at a spacing of 7.0 mm between implants. Impressions will be made of these implants prior to having healing abutments attached to allow fixed partial dentures (FPDs) to be ready at the respective loading intervals. At time intervals of 4, 8 and 12 weeks after implant placement, baseline data will be collected which includes individual implant stability (measured by the Periotest device), radiographic one levels (digitally measured using standardized radiographs), and occlusion features (location and clinically-determined intensity of contact) measured following screw fastening. Following baseline data collection, the FPDs will be monitored at monthly intervals for stability and occlusal features. Terminal data will be collected after 6 months of loading or when implants are determined to have failed. Failure will be established by Periotest scores of >+10, and the implant will be removed following double bone labeling using calcein and tetracycline at 1 week intervals. Implants showing Periotest scores of >+5 will be radiographed and the occlusion will be adjusted as required. At the 6 month loading period, all animals will be double bone labeled at the 1 week interval, and the final data will be collected. All the implants, failed or successful, will be processed for histomorphometric evaluation. The data will be analyzed for implant survival and a comparison of the three time groups will be done to determine whether there is a significant difference for implant lifetime when loaded at the three different time periods. Histomorphometric data will be analyzed using a repeated measures ANOVA to account for correlation of implants within animals, and contrasts will be performed to identify differences between the 12 weeks loading and both the 4 and 8 weeks loading groups. Also, the failed implants will be investigated as to histomorphometric differences compared with surviving implants overall and within time groups.
| George, Kudiyirickal Marina; Choi, Yong-Geun; Rieck, Kevin L et al. (2011) Immediate restoration with ti-unite implants: practice-based evidence compared with animal study outcomes. Int J Prosthodont 24:199-203 |
| Knobloch, Lisa; Larsen, Peter A; Rashid, Bob et al. (2004) Six-month performance of implants with oxidized and machined surfaces restored at 2, 4, and 6 weeks postimplantation in adult beagle dogs. Int J Oral Maxillofac Implants 19:350-6 |
