Fibroblast and bacterial adhesion on a 3D-printed polyetheretherketone-based implant material

This study investigated fibroblast and bacteria proliferation on polyetheretherketone (PEEK)-implant material 3D-printed by fused deposition modeling (FDM) in comparison to titanium (cp-Ti) and zirconia (ZrO₂). Four groups were tested, including horizontally FDM-printed PEEK (PH), vertically printed FDM-PEEK (printed vertically [PV]), cp-Ti and ZrO₂. Human gingival fibroblasts were cultured on discs (15/group), with viability evaluated at 1-, 3-, and 7-d and cytokine production (IL-6 and IL-8) measured at 3-d. Discs (9/group) were exposed to Streptococcus oralis with bacteria counted at 1- and 2-d. Discs underwent scanning electron microscopy and surface roughness testing. Although fibroblast proliferation was similar for all groups at 24 h, values were significantly higher for PV than ZrO₂ at 3-d. At 7-d, fibroblast proliferation was significantly lower on PH than cp-Ti. Bacterial adhesion for ZrO₂ was lower than other groups at 24 h and lower than PV and PH at 48 h. IL-8 production was similar between groups, whereas IL-6 was higher on cp-Ti compared to ZrO₂. PV was significantly rougher than other groups. FDM-PEEK induces early fibroblast adhesion and viability and bacterial colonization comparable to reference implant materials. The positive outcomes of this study underscore FDM-PEEK as a promising biomaterial comparable to established implant and prosthetic materials in terms of favorable biological responses and potential soft-tissue seal.