The Performance of Titanium-Zirconium Implants in the Elderly: A Biomechanical Comparative Study in the Minipig

ObjectivesThe aim of this study was to test the following hypothesis: (1) Aging would adversely affect bone integration of implants; (2) Titanium-zirconium-SLActive (TiZr-SLActive) implant might perform better in osseointegration than Ti-SLA implant in aged group. Materials and MethodsThirteen miniature pigs (six of them were young adult minipigs, with other seven being aged ones.) were enrolled in this study. The right mandibular premolars (P1, P2, P3) and the first molar (M1) were extracted in all animals. Three months later, one TiZr-SLActive and one Ti-SLA implants were inserted into the endentulous area in mandible of each animal. The animals were sacrificed 8 weeks after placement of implants. Implants in the mandibles were used for removal torque (RT) tests, while vertebra and femur being retrieved for bone mineral density (BMD) tests. ResultsImplant success rate in the young group was significantly higher than that in the aged group. Higher survival rate of implants was also observed in younger group than that in the aged group but without significant difference. Within the young group, mean value for peak RT of Ti-SLA implants was higher than that of TiZr-SLActive implants without significant difference. In the aged group, the TiZr-SLActive implants showed a higher mean value for peak RT than Ti-SLA implants. No significant difference was found in the mean BMD in both vertebra and femur between different age groups. ConclusionsWithin the limits of this study, aging could negatively affect osseointegration of dental implants. TiZr-SLActive implants might to some degree compensate for the compromise in osseointegration brought by aging.