Hanan ABDULLATEF, Omar OMAR, Jaffar ALDANDAN, Hatem ABUOHASHISH, Neveen AYAD, Faisal AL-ONIZAN, Nada AL-DOSSARY, Attika AL-SADAH, Deem AL-SUHAIBANI
European Endodontic Journal - 2026;11(7):319-329
Objective: This study aims to evaluate i) the antimicrobial and immunomodulatory effects of calcium hydroxide (Ca(OH)2) when combined with nonsteroidal anti-inflammatory drugs (NSAIDs) against Enterococcus faecalis (E. faecalis), and ii) to assess the inflammatory and cytocompatibility responses of this combination in human peripheral blood mononuclear cells (PBMCs). Methods: Three-week-old E. faecalis biofilms were developed on human dentine blocks and subsequently treated for 1 week with Ca(OH)2 alone or combined with 20% ketoprofen (Keto), 20% diclofenac sodium, or gentamicin. Biofilm disruption was assessed using scanning electron microscopy (SEM), while gelatinase (GelE) activity served as a marker of bacterial virulence. Culture supernatants were used to stimulate PBMCs in vitro for 24 hours. The immunomodulatory responses of PBMCs were evaluated using fluorescence microscopy, NucleoCounter NC-202(TM) cell analysis for live/total cell counts and viability, and ELISA for TNF-alpha and IL-1beta secretion. Results: All medicated groups showed significantly reduced GelE activity compared to untreated controls, with the most substantial suppression observed in the Ca(OH)2 + diclofenac group. While Ca(OH)2 + diclofenac and Ca(OH)2 + gentamicin were most effective in reduceding TNF-alpha and IL-1beta levels, Ca(OH)2 + diclofenac was also associated with the lowest PBMCs viability and highest cell aggregation. Ca(OH)2 + Keto preserved PBMCs viability while maintaining anti-inflammatory and antimicrobial effects. Conclusion: Combining Ca(OH)2 with diclofenac sodium or Keto enhances the antimicrobial and immunomodulatory efficacy of Ca(OH)2 against E. faecalis biofilms. Ca(OH)2 + diclofenac reduced PBMCs viability, suggesting a strong immunosuppressive effect that may be beneficial in dampening excessive inflammation but also raises concerns regarding cytocompatibility and dose optimization. Ca(OH)2 + keto demonstrated a more favourable balance between antimicrobial activity and biocompatibility, supporting its potential as a non-antibiotic adjunct in intracanal medication protocols.
