Effects of intracanal medicaments on inflammation and mineralization in LPS-induced human apical papilla cells

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 cell viability, inflammatory cytokine expression, and mineralization potential in lipopolysaccharide (LPS)-induced human apical papilla cells (hAPCs). hAPCs were pretreated with 1 µg/mL LPS for 24 h and then treated with TAP (2.5 mg/mL), DAP (2.5 mg/mL), CH (1 mg/mL), or Dex (10 µM). Cell viability was evaluated using the alamarBlue ® assay at 6, 12, 24, and 48 h. Inflammatory cytokine gene expression ( TNF -α and IL-6 ) were assessed by qRT-PCR after 7 days of treatment. Mineralization was examined after 21 days under osteogenic conditions using Alizarin Red S staining and qRT-PCR for dentin sialophosphoprotein ( DSPP ) and bone sialoprotein ( BSP ). Statistical significance was set at p < 0.05. TAP significantly reduced cell viability ( p < 0.05), increased TNF -α and IL-6 expression levels compared with the other groups ( p < 0.05), and reduced mineralization ( p < 0.05). CH caused significant cytotoxicity ( p < 0.05) but induced mineralized nodule formation and enhanced DSPP and BSP expression. DAP and Dex had minimal effects on inflammation and mineralization. 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.