Filler Particles Used in Dental Biomaterials Induce Production and Release of Inflammatory Mediators In Vitro

Although dental composites are in extensive use today, little is known about the biological effects of the filler particles. As composite materials are gradually broken down in the aggressive environment of the oral cavity, the filler particles may leak and induce toxic effects on the surrounding tissue and cells. The aim of this study was to elucidate possible adverse biological effects of commonly used dental filler particles; bariumaluminiumsilica (BaAlSi) and bariumaluminiumfluorosilica (BaAlFSi) with mean size of 1 mu m. BEAS-2B cells were used as a model system. Particle morphology, mean particle size in solution, and particle surface charge were determined by scanning electron microscopy and Malvern zetasizer technology, respectively. Enzyme-linked immunosorbent assay was used to detect secretion of cytokine and chemokine (IL-8 and IL-6) and quantitative PCR for detection of gene activity. Both types of particle increased the release of IL-6 and IL-8 in a dose-dependent manner. BaAlFSi particles induced a more marked IL-8 response compared to BaAlSi particles, whereas no significant difference was observed for the IL-6 response. Mechanistic studies using specific inhibitors and activators indicated that cyclic AMP-dependent protein kinase A is partly involved in the observed IL-8 response. In conclusion, we consider dental filler particles to have potential to induce adverse biological response in cell cultures. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 89B: 86-92. 2009