Considering the close link between inflammation and the induction of regenerative processes in the dental pulp, as well as the lack of pre-clinical data on the potential therapeutic role that selective iNOS inhibitors might play in in vitro models of pulpitis, this work aims at studying the effects played by the two promising compounds CM544 and FAB1020 in LPS-stimulated DPSCs compared to the well-known iNOS inhibitor 1400W in terms of cytotoxicity and cell responses towards inflammation. This evidence concerns the gene NOS2 and pulpitis.