Cytotoxicity, biocompatibility and osteoinductive profile of an MTA‐hydrogel‐based cement: An in vitro and animal study

Abstract Aim This study aimed to evaluate the cytotoxicity, biocompatibility and osteoinductive profile of a mineral trioxide aggregate (MTA)‐hydrogel‐based material (MTA Flow) in comparison with MTA Angelus. Methodology Cell viability was evaluated in human periodontal ligament stem cells (hPDLSCs) using the methyl‐thiazol‐tetrazolium (MTT) colourimetric assay. Polyethylene tubes containing the tested materials and empty polyethylene tubes (control) were implanted in the subcutaneous tissue of Wistar rats. Cellular (lymphocyte infiltration) and extracellular events (ECM; collagen fibres) were analysed in histological sections. Immunohistochemical (collagen I, osteopontin, bone sialoprotein, bone morphogenetic protein4) analyses were also performed. Results At 24, 48 and 72 h, all tested groups showed cell viability similar to control ( p > .05). Regarding biocompatibility, all groups showed similar cellular events represented by a slight inflammatory reaction characterized by hyperaemia and a mild lymphocytic inflammatory infiltrate. The analysis of lymphocytes during the time showed a decrease in these cells in the control group and a significant interaction between MTA Angelus and control ( p < .001), with MTA Angelus showing a more extensive inflammatory infiltrate. Regarding fibres, an increase in content was observed in all groups during the experimental time (7, 30 and 60 days), however, no difference was detected among the experimental groups ( p = .063). After 60 days, the immunoexpression of bone matrix proteins in the MTA Flow group was similar to or higher than that observed in the MTA Angelus and in the control group. Conclusions MTA Flow showed a non‐cytotoxic behaviour, biocompatibility and ability to stimulate tissue mineralization.