Immunohistochemical analysis of subcutaneous tissue reactions to methacrylate resin-based root canal sealers

Yamanaka Y, Shigetani Y, Yoshiba K, Yoshiba N, Okiji T. Immunohistochemical analysis of subcutaneous tissue reactions to methacrylate resin-based root canal sealers. International Endodontic Journal, 44, 669–675, 2011. Abstract Aim To investigate subcutaneous tissue reactions to methacrylate resin-based root canal sealers by immunohistochemical assessment of inflammatory/immunocompetent cell infiltration. Methodology Silicone tubes containing freshly mixed Epiphany SE sealer, MetaSEAL, Super-Bond RC sealer, or a zinc oxide-eugenol sealer (Canals) were subcutaneously implanted into the backs of Wistar rats. Solid silicone rods implanted in different animals served as controls. After 7, 14 and 28 days, connective tissue surrounding the implants (n = 8, each) was processed for immunoperoxidase staining using OX6 (reactive to major histocompatibility complex class II molecules), ED1 (reactive to macrophages), and W3/13 (reactive primarily to neutrophils), and the number of positively stained cells within each field (1.2 × 0.8 mm) was enumerated. Statistical differences were analysed with Friedman’s test and Scheffe’s test (comparisons between test materials) or Mann–Whitney’s U-test (test–control comparisons). Results Canals showed a significantly higher number of W3/13-positive cells (mostly neutrophils) than MetaSEAL at 28 days (P