In Vitro Biocompatibility, Inflammatory Response, and Osteogenic Potential of 4 Root Canal Sealers: Sealapex, Sankin Apatite Root Sealer, MTA Fillapex, and iRoot SP Root Canal Sealer

Introduction: The objective of this study was to compare the cytotoxicity, inflammatory response, osteogenic effect, and the signaling mechanism of these biologic activities of 4 calcium compound-based root canal sealers (ie, Sealapex [Sybron Kerr, WA], apatite root sealer [ARS; Dentsply Sankin, Tokyo, Japan], MTA Fillapex [Angelus Industria de Produtos Odontologicos S/A, Londrina, PR, Brazil], and iRoot SP [Innovative BioCreamix Inc, Vancouver, Canada]) in human periodontal ligament cells. Methods: Cytotoxicity was assessed using the 3(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide assay. Levels of inflammatory mediators were measured by enzyme-linked immunosorbent assay, reverse-transcription polymerase chain reaction, and Western blot analysis. Osteogenic potential was evaluated by alkaline phosphatase activity, alizarin red staining, and marker genes by reverse-transcription polymerase chain reaction. The signal transduction pathways were examined by Western blotting. Results: None of the sealers were cytotoxic. ARS, MTA Fillapex, and iRoot SP induced a lower expression of proinflammatory mediators than Sealapex. All sealers increased ALP activity and the formation of mineralized nodules and up-regulated the expression of osteoblastic marker messenger RNA. ARS, MTA Fillapex, and iRoot SP showed superior osteogenic potential compared with Sealapex. The expression and/ or activation of integrin receptors and downstream signaling molecules, including focal adhesion kinase, paxilli, Akt, mitogen-activated protein kinase, and nuclear factor kappa B, was induced by ARS, MTA Fillapex, and iRoot SP treatment but not by Sealapex treatment Conclusions: We show for the first time that ARS, MTA Fillapex, and iRoot SP induce a lower expression of inflammatory mediators and enhance osteoblastic differentiation of PDLCs via the integrin-mediated signaling pathway compared with Sealapex.