Differences in proliferation,differentiation,and cytokine production by bone cells seeded on titanium–nitride and cobalt–chromium–molybdenum surfaces

Titanium–nitride coating is used to improve cobalt–chromium–molybdenum implant survival in total knee arthroplasty, but its effect on osteoconduction is unknown. Chromium and cobalt ions negatively affect the growth and metabolism of cultured osteoblasts while enhancing osteoclastogenic cytokine production. Therefore, it was hypothesized that a titanium–nitride surface would enhance osteoblast proliferation and/or differentiation and reduce osteoclastogenic cytokine production compared with a cobalt–chromium–molybdenum surface. MC3T3-E1 osteoblasts showed increased proliferation and decreased differentiation on titanium–nitride, while cytokine interleukin-6 production was higher on porous cobalt–chromium–molybdenum (p < 0.05), though interleukin-1β was occasionally detected on both surfaces. These findings suggest improved osteoconduction on titanium–nitride compared with cobalt–chromium–molybdenum surface.