title: Toll-like receptors, LPS, and dental monomers.
abstract: Unreacted monomers released from dental resin-based composites at non-cytotoxic concentrations cause a depletion of glutathione and an increase of reactive oxygen species (ROS), leading to, e.g., DNA damage and apoptosis. ROS-sensitive MAP-kinases are activated by HEMA and TEGDMA. MAP-kinases are also involved in the bacteria-triggered cell responses of the innate immune system, e.g., after bacterial lipopolysaccharide (LPS) binding to the Toll-like receptor (TLR) 4. Therefore, both bacteria and monomers imply environmental stress to pulp tissue, and they may influence the target cell reactions in a combined way. In macrophages, cell-surface antigens and cytokines were up-regulated after exposure to LPS, but TEGDMA caused a significant down-regulation. Regulation was dependent on exposure time, indicating that LPS and TEGDMA act differently on MAP-kinases. Furthermore, the cell type played a decisive role. Inhibition of the immune response may result in a decrease in inflammatory symptoms and/or a reduced defense capacity against bacteria.
authors.affiliation: Department of Operative Dentistry and Periodontology, University Medical Centre Regensburg, Germany. gottfried.schmalz@klinik.uni-regensburg.de
authors.forename: G
authors.initials: G
authors.lastname: Schmalz
authors.forename: S
authors.initials: S
authors.lastname: Krifka
authors.forename: H
authors.initials: H
authors.lastname: Schweikl
mesh_terms: D001419:Bacteria / Q000276:immunology; D003188:Composite Resins / Q000494:pharmacology*; D003764:Dental Materials / Q000494:pharmacology*; D003782:Dental Pulp / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology; D005978:Glutathione / Q000037:antagonists & inhibitors; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects; D018836:Inflammation Mediators / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects; D018384:Oxidative Stress / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D051193:Toll-Like Receptors / Q000187:drug effects*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D017382:Reactive Oxygen Species; D051193:Toll-Like Receptors; D020928:Mitogen-Activated Protein Kinases; D005978:Glutathione