Polyetheretherketone (PEEK) is increasingly used in oral and cranio-maxillofacial surgery as artificial implant material. In this study, we explored the influence of surface processing of fused deposition modeling (FDM) manufactured carbon fiber-reinforced polyetheretherketone (CFR-PEEK) on wettability, topography, and biocompatibility.
Materials and Methods:
PEEK composite reinforced by 5% carbon fibers (80-150 µm in length and 7 µm in diameter) were used to produce disk samples (14 mm diameter, 1 mm thickness) by FDM. The samples were divided into three groups, untreated, polished, and sandblasted (n = 12 per group). Topography and wettability were measured by profilometry and drop shape analysis. Cytotoxicity was tested according to ISO 10993-5:2009.
An extract test and a direct contact test were performed. Samples were extracted in cell culture medium for 24 h. L929 fibroblasts were subjected to extracts (24 h) and tested for inhibition of metabolic activity. For direct contact, cells were seeded directly onto the samples. After 24 h incubation, cell adhesion and viability were evaluated by LIVE/DEAD staining.
Untreated CFR-PEEK samples showed a rougher and more hydrophobic surface than polished and sandblasted ones. The extract test did not reveal any cytotoxic effects. Cell metabolic activity was comparable to the negative control group (Ti), even though after surface treatment some carbon fibers were exposed. After 24 h incubation in direct contact, it was observed that more cells attached to the untreated CFR-PEEK sample surfaces than to the treated samples. It was obvious, however, that the cells accumulated in the surface grooves resulting from the manufacturing process.
1) No toxic substances were introduced during the FDM manufacturing process of CFR-PEEK.
2) Surface treatments leading to partial exposure of the fiber compound in the bulk material did not lead to increased cytotoxicity.