Cellular and Mechanical Responses to Zinc Polycarboxylate Cement Modified With 5% or 10% Potassium Nitrate: An In Vitro Study

This study investigated the biological response of human peripheral blood mononuclear cells (PBMCs) to zinc polycarboxylate (ZP) cement modified with 5% or 10% potassium nitrate (KNO 3 ) and assessed its mechanical properties. Discs of unmodified ZP, ZP + 5% KNO 3 , ZP + 10% KNO 3 , or mineral trioxide aggregate (MTA) were indirectly exposed to PBMCs using a transwell system. Cells were incubated with or without lipopolysaccharide (LPS) stimulation. Cytotoxicity (LDH release), viability, IL‐6 and TGF‐β secretion were evaluated. Material pH, ion release, compressive strength and microhardness were also assessed. ZP + 5% KNO 3 significantly reduced LDH and IL‐6 levels and increased TGF‐β release compared to ZP alone. Mechanical strength was maintained in ZP + 5% KNO 3 but decreased at 10% KNO 3 . MTA showed lower strength but higher cell viability. ZP + 5% KNO 3 demonstrated a balanced profile of immunomodulation, regenerative signalling and mechanical integrity, supporting its potential use in vital pulp therapy. Further in vivo investigations are recommended.