Enhanced osteoconductivity of micro-structured titanium implants (XiVE S CELLplus^™) by addition of surface calcium chemistry: A histomorphometric study in the rabbit femur

Objectives: This study evaluated the osseointegration in rabbit cancellous bone of titanium (Ti) implants with a micro-topographically complex surface structure produced by grit-blasting/acid-etching with or without the addition of surface calcium ion (Ca) chemistry. Material and methods: Micro-structured Ti implants (XiVE S CELLplus^™ screw implant, Dentsply Friadent GmbH) were hydrothermally treated in an alkaline Ca-containing solution to produce a nano-structured Ca-incorporated oxide surface layer. The surface characteristics were evaluated by scanning electron microscopy and stylus profilometry before and after Ca surface treatment. Twenty implants (10 control and 10 experimental) were placed in the femoral condyles of 10 New Zealand White rabbits. Histomorphometric analysis was performed 6 weeks after implantation. Results: Ca-incorporated and untreated control implants showed similar surface morphologies and surface roughness values at the micron scale. Untreated micro-structured Ti implants achieved a high degree of bone-to-implant contact (BIC), and Ca incorporation further increased BIC% (P<0.05). Active new bone apposition was found on surfaces of Ca-incorporated implants in areas of loose trabeculae. Conclusion: The nano-structured Ca-incorporated oxide surface significantly enhanced osteoconductivity of micro-structured Ti implants in rabbit cancellous bone. Results indicate that this surface produced by simple hydrothermal treatment may be effective in improving the osseointegration of implants with micro-topographically complex surface structures in areas of loose cancellous bone.