MTT-Based Cytotoxicity Assessment of Chitosan- and Octenisept®-Biomodified Mineral Trioxide Aggregate in Human Periodontal Ligament Fibroblasts

Calcium silicate-based repair materials are widely used in endodontics, and bioinspired polymeric biomodification may influence their cellular response. However, the cytotoxicity profile of mineral trioxide aggregate (MTA) modified with Octenisept® or with an acetic acid-based chitosan vehicle has not been specifically evaluated in a controlled design comparing chitosan-modified MTA groups under parallel MTA extract and direct solution exposure conditions, although biomodifier effects may differ when tested alone and when incorporated into an MTA matrix. This in vitro study evaluated the MTT-based cytotoxicity profile of MTA subjected to bioinspired chitosan-based biomodification in human periodontal ligament fibroblasts (hPDLFs), using Octenisept® as an antiseptic comparator biomodifier and 1% acetic acid as the vehicle control. Extracts of unmodified-MTA, MTA + 1% acetic acid, MTA + 1% chitosan, MTA + 3% chitosan and MTA + Octenisept® were tested at 100%, 50% and 25% concentrations. The corresponding solutions were tested under direct exposure at 100%, 50%, 25% and 12.5%. Cell viability was assessed after 24 and 72 h using the MTT assay, and values below 70% were considered cytotoxic according to ISO 10993-5. Direct solution exposure produced stronger cytotoxicity, particularly for Octenisept®. Among the MTA extract groups, only MTA + 1% chitosan maintained non-cytotoxic cell viability at 72 h under undiluted extract conditions.