Effects of Intracanal Medicaments on the Expressions of Inflammatory and Mineralization Markers in Lipopolysaccharide-Induced Human Apical Papilla Cells

Background Regenerative endodontic procedures rely on modulating inflammation and promoting odontogenic differentiation in stem cells from the apical papilla. This study aimed to investigate the effects of intracanal medicaments, including triple antibiotic mixture (TAP), double antibiotic mixture (DAP), calcium hydroxide (CH), and dexamethasone (Dex), on inflammatory cytokine expression, cell viability, and mineralization potential in lipopolysaccharide (LPS)-induced human apical papilla cells (hAPCs). Methods hAPCs were pretreated with 1 µg/mL LPS for 24 hours and then treated with TAP (2.5 mg/mL), DAP (2.5 mg/mL), CH (1 mg/mL), or Dex (10 µM) for 7 days. Inflammatory cytokine gene expressions ( TNF -α and IL-6 ) were assessed by qRT-PCR. Cell viability was evaluated using the alamarBlue® assay at 6, 12, 24, and 48 hours. Mineralization was examined after 21 days under osteogenic conditions using Alizarin Red S staining and RT-PCR for dentin sialophosphoprotein ( DSPP ) and bone sialoprotein ( BSP ). Statistical significance was set at p < 0.05. Results TAP significantly increased TNF -α and IL-6 expressions and reduced cell viability and mineralization. CH induced mineralized nodule formation and enhanced DSPP and BSP expression but caused significant cytotoxicity. DAP and Dex had minimal effects on inflammation and mineralization. Conclusion All medicaments, even at low concentrations, reduced hAPC viability. TAP promoted inflammation and impaired mineralization. CH induced strong mineralization responses but showed high cytotoxicity. DAP and Dex demonstrated better biocompatibility with minimal effects on inflammation and odontogenic differentiation. These findings suggest varying impacts of intracanal medicaments on inflammatory modulation and odontogenic potential, with implications for regenerative endodontic procedures.