Add on Chlorhexidine and Nanoformulations to Calcium Hydroxide Enhances Efficacy of Endodontic Retreatment: Study
India: Researchers have found in a new study that calcium hydroxide remains a valuable intracanal medicament, with improved efficacy when combined with chlorhexidine or in nanoformulations. However, limited and heterogeneous evidence highlights the need for larger, standardized clinical trials.
The findings, published in the Journal of Conservative Dentistry and Endodontics, provide fresh insights into strategies for managing complex endodontic retreatment cases.
Persistent infections caused by biofilm-forming bacteria such as Enterococcus faecalis often complicate endodontic retreatments. Residual filling materials from prior procedures can further hinder effective disinfection, making intracanal medicaments (ICMs) an essential part of successful therapy. Calcium hydroxide [Ca(OH)₂] has long been used in this role because of its strong alkalinity, antimicrobial activity, and ability to promote periapical tissue healing. Yet its consistency in reducing pain and infection during retreatment has been debated.
To address this uncertainty, Dr. S. Delphine Priscilla Antony and colleagues from the Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Chennai, performed a systematic review of clinical trials published between January 2005 and August 2024. The team searched four major databases—PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Library—to identify randomized controlled trials that evaluated calcium hydroxide either alone or in combination with other agents or adjunctive techniques. Risk of bias in each study was assessed using the Cochrane RoB 2.0 tool.
Six eligible trials involving a total of 430 participants were included in the analysis. Four of these examined postoperative pain using validated scales such as the Visual Analog Scale, Numeric Rating Scale, and Verbal Rating Scale. Two studies investigated the incidence of flare-ups; one focused on bacterial reduction, and another assessed inflammatory markers.
Key Findings:
- Calcium hydroxide combined with chlorhexidine (CHX) or in nanoparticle form provided better control of postoperative pain than calcium hydroxide alone.
- The combination also resulted in fewer flare-ups compared to calcium hydroxide used alone.
- Four of the included trials were assessed as having a low risk of bias, while two had a moderate risk.
- The effectiveness of calcium hydroxide alone in reducing postoperative discomfort was variable.
- Differences in individual patient factors and clinical protocols likely contributed to the inconsistent outcomes.
- Previous studies also support the advantage of combining calcium hydroxide with chlorhexidine, highlighting the value of combination therapy.
Despite encouraging findings, the review highlights key gaps. Considerable heterogeneity existed among the included studies in terms of outcome measures, sample sizes, and methodologies. Such variability makes it difficult to draw definitive conclusions or establish universal treatment guidelines. The researchers call for future randomized controlled trials with larger patient populations, standardized assessment tools, and longer follow-up periods to strengthen the evidence base.
For practicing endodontists, the study highlights the importance of tailoring intracanal medicament choices to the specific needs of each retreatment case. While calcium hydroxide remains a reliable option, combining it with agents such as chlorhexidine or exploring nanoformulations may enhance antimicrobial action and improve patient comfort.
"Until more robust data are available, clinicians are advised to consider individual case complexity and emerging evidence when selecting the most appropriate treatment approach," the authors concluded.
Reference:
Chowdhury, Kashmiri1; Antony, S. Delphine Priscilla1; Solete, Pradeep1; Elango, Praveen Kumar2; Sanghavi, Amee2; Muskan, Shreshtha1. Effectiveness of calcium hydroxide as an intracanal medicament in endodontic retreatment: A systematic review of clinical outcome. Journal of Conservative Dentistry and Endodontics 28(9):p 849-858, September 2025. | DOI: 10.4103/JCDE.JCDE_397_25
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