Preliminary evaluation of titanium-coated PEEK implants

A series of 40 titanium-coated and uncoated polyetheretherketone (PEEK) cylindrical implants were placed in unicortical sites in femurs of 4 mongrel dogs. The implants were evaluated mechanically and histologically at periods of 4 and 8 weeks. Interface attachment strength was calculated for each specimen, as well as measurements of bone contact, porosity, bone ingrowth, inflammatory response and mode of failure. Statistical analysis revealed the uncoated implants had significantly higher shear strength values at 4 weeks, but no significant difference from the coated implants at 8 weeks. There was no significant increase in bone contact between 4 and 8 weeks for either the coated or uncoated specimens. At both 4 and 8 weeks, the coated specimens had significantly higher percentages of bone contact.