Does an interim dressing with calcium hydroxide reduce endotoxins between endodontic appointments?

Area of Science:

• Endodontics
• Microbiology
• Materials Science

Background:

• Lipopolysaccharide (LPS) is a key virulence factor in endodontic infections.
• Calcium hydroxide (CH) is widely used as an intracanal medicament for its antimicrobial properties.
• Evaluating the efficacy of CH against LPS is crucial for optimizing endodontic treatment protocols.

Purpose of the Study:

• To systematically review and meta-analyze the antimicrobial efficacy of calcium hydroxide (CH) interim dressings against lipopolysaccharide (LPS).
• To compare the effectiveness of CH with chemo-mechanical preparation (CMP) and antimicrobial substances (AS) in reducing LPS.
• To assess the impact of CH on LPS levels over time.

Main Methods:

• Comprehensive literature search across multiple databases (PubMed, Cochrane, Embase, etc.) and grey literature.
• Inclusion of randomized and non-randomized clinical and experimental studies evaluating LPS reduction after CH dressing.
• Meta-analysis using random-effect models, with subgroup analyses based on CH use, CMP, AS, and irrigants; risk of bias assessment using modified Cochrane RoB and Robins-1 tools.

Main Results:

• CH interim dressing resulted in a significant reduction in LPS levels, outperforming CMP and AS.
• When CH was used as an interim dressing, 98.9% of teeth showed LPS reduction compared to 61.7% without CH (when AS was used).
• CH, with or without AS, significantly reduced mean LPS levels both before and after CMP, with reductions observed up to 30 days; however, the certainty of evidence was very low.

Conclusions:

• Interim dressing with CH effectively reduces LPS levels, surpassing CMP and AS, but does not achieve complete elimination.
• The current evidence suggests CH is beneficial in reducing LPS, but further research is needed to confirm its impact on clinical outcomes.
• The very low certainty of evidence highlights the need for high-quality studies to validate these findings.