Impact of Surface Chemistry Modifications on Speed and Strength of Osseointegration

Purpose: To compare the bone responses of chemically modified implants using the plasma immersion ion implantation and deposition method with those of blasted implants. Materials and Methods: The titanium implants were blasted with resorbable blasting media (RBM) and designated as controls. The ion-implanted implants were divided into two test groups, namely, calcium (Ca) and magnesium (Mg) implants. Six implants (two implants per group) were placed into the proximal tibias of 11 New Zealand white rabbits. Fluorochrome labeling was administered at 2 and 4 weeks after surgery. Resonance frequency analysis (RFA) was conducted immediately after surgery and at 6 weeks of healing. The removal torque was measured in half of the tibiae. The implants in another tibia were subjected to fluorescence analysis and histologic and histomorphometric evaluations. Results: The fluorescence analysis suggested that osteoconductivity was improved in the early osseointegration stages in the Ca and Mg implants. In the cortical region, the bone-to-implant contact in the Mg implants and the bone area % in the Ca and Mg implants were higher than those in the RBM implants (P .05). All groups demonstrated similar biomechanical strengths with respect to the RFA and the removal torque measurements. Conclusion: The osseointegration speed and the bone contact were positively affected by the Ca and Mg ion implantation, especially in the Mg implants, because of the synergistic effect. However, no remarkable differences were found in biomechanical strength in the later osseointegration stages. Keywords: calcium, ion implantation, magnesium, surface chemistry