SURFACE ACTIVATION OF POLYETHERETHERKETONE (PEEK) AND FORMATION OF CALCIUM-PHOSPHATE COATINGS BY PRECIPITATION

Plasma activation of polyetheretherketone (PEEK) surfaces and the infl uence on coating formation in a supersaturated calcium phosphate solut ion was investigated in this study. It was observed that plasma treatm ent in a N-2/O-2 plasma had a significant effect on the wettability of the PEEK surface. The contact angle decreased from 85 degrees to 25 d egrees after plasma treatment. Cell culture testing with osteoblastic cell lines showed plasma activation not to be disadvantageous to cell viability. X-ray photoelectron spectroscopy (XPS) analysis was perform ed to characterize the chemical composition of the PEEK surfaces. It w as observed that the O-1s intensity increased with plasma activation t ime. At the C-1s peak the appearance of a shoulder at higher binding e nergies was observed. Coating of PEEK was performed in a supersaturate d calcium phosphate solution. Coating thicknesses of up to 50 mu m wer e achieved after 24 days of immersion. Plasma activation followed by n ucleation in a highly saturated hydroxyapatite solution had a positive effect on the growth rate of the layer on PEEK. Chemical analysis rev ealed that the coating consists of a carbonate-containing calcium phos phate.