Programmed Cell Death Induced in WEHI 13 var Cultured Fibroblasts by Exposure to Dental Composite Resin Eluates.

Purpose: Earlier studies have shown that in vitro exposure to single compounds released from composite resins is able to induce cell death via apoptosis and/or necrosis. The purpose of this study was to evaluate the effect of eluates of commercially available composites used for direct (Tetric Ceram/Ivoclar-Vivadent, Simile/Pentron, Filtek Z-250/3M ESPE) and indirect restorations (Adoro/Ivoclar-Vivadent and Conquest Sculpture/Pentron) on the type of cell death of cultured WEHI 13 var fibroblasts. Materials and Methods: Cells exposed to eluates of the materials were assayed by MTT for cytotoxicity, flow cytometry for cell death, biochemically for caspase-3 activation and fluorescent microscopy with Acridine Orange for morphological changes. Results: The 3 direct composite resin eluates induced extensive apoptosis characterized by externalization of phosphatidylserine at the cell surface, activation and positive cytoplasmic expression of caspase-3, and chromatin disintegration. This was accompanied by morphological changes, such as cell enlargement micromultinucleation and membrane blebbing. On the other hand, the other 2 composite resins for indirect restorations were much less cytotoxic in all biological endpoints investigated. Conclusion: These findings suggest that composite resins used for direct and indirect restorations differ extensively in their cytotoxic potential and their ability to induce programmed cell death. This signifies the role of composition and polymerization of these 2 classes of biomaterials with respect to their biologic behavior. [ABSTRACT FROM AUTHOR]