PEEK (Poly ether etherketone), is an increasingly used alternative material in the dental field, e. g. for abutments or denture frameworks, especially for CAD/CAM-manufactured restorations. Peek offers several advantages, it is easily machinable, elastic and does not release metal ions.
Besides fulfilling the required mechanical properties for the respective application, dental materials should not favour the adhesion of oral microorganisms. To address this point, we investigated the initial plaque adhesion to two commercially available dental PEEK materials (BioHPP and BioHPP dentin-shade 2, bredent, Germany), compared with two dental composites (Tetric EvoCeram, ESPE Sinfony), two metal-based materials (titanium, brealloy F400) and two ceramics (Vita VM13, e.max Press), respectively.
Round sample discs (14 mm diam., 2mm height) of the 8 materials were polished with abrasive SiC papers up to P4000. Ra of the samples ranged between 0.04 µm for BioHPP and 0.11 µm for Vita VM13, respectively. Bacterial adhesion was quantified in an experimental stop/flow model consisting of an intermittently stirred reaction vessel in which the samples were subjected to mixed oral bacterial cultures from five volunteers. After 4 h incubation, bacteria adhering to the respective samples were quantified by a luminescence assay. Statistical differences between groups were analysed by ANOVA (p<0.05).
The lowest bacterial adhesion was observed on the ceramic and metallic samples, however, differences were only minor. The mean relative adhesion of bacteria to BioHPP did not significantly differ from the tested ceramics, metallic materials, or the polymer-based composites. The only statistically significant difference was observed between the ceramics and metals on the one hand and BioHPP dentinshade 2, which showed an approximately doubled amount of adhered bacteria compared to the former materials. With respect to clinical performance, however, this difference can be regarded as irrelevant.
Provision of samples by bredent GmbH & Co.KG is gratefully acknowledged.