ANCHORAGE OF TIO2-BLASTED, HA-COATED, AND MACHINED IMPLANTS - AN EXPERIMENTAL-STUDY WITH RABBITS

The purpose of this study was to evaluate the histometrical and biomec hanical anchorage of TiO2-blasted implants and TiO2-blasted implants c oated with hydroxyapatite. The control implants were machined. Twenty- six rabbits had a total of 156 implants placed in the proximal part of the tibia. Each rabbit had a machined, a TiO2-blasted, and a TiO2-bla sted, HA-coated implant placed in each tibia. After a healing period o f 3 and 12 weeks, respectively, the implants placed in the right tibia were used for removal torque test, and the implants placed in the lef t tibia were used for histomorphometrical measurements. Preoperatively , implants from the same batches were examined topographically with a TopScan 3D system. The TiO2-blasted implants demonstrated significantl y higher removal torque values than the machined implants, and they al so had a significantly more irregular surface. Furthermore, significan tly higher bone-to-implant contact length fractions were measured adja cent to the TiO2-blasted implants in contrast to the machined implants . The advantages of a TiO2-blasted surface were more pronounced after 3 weeks than after 12 weeks. The results demonstrated that it was poss ible to influence the anchorage of implants by altering the surface st ructure morphology. The new method with TiO2 blasting on the titanium surface improves the anchorage of implants but is not yet practicable for HA coating. (C) 1995 John Wiley & Sons, Inc.