Does calcium hydroxide reduce endotoxins in infected root canals? Systematic review and meta-analysis.

Abstract Introduction To evaluate the potential of endotoxin reduction by comparing the number of lipopolysaccharides (LPS) before and after the use of calcium hydroxide (Ca(OH)2) as intracanal medication (ICM). Methods Searches were performed up to June 2020. Clinical and experimental studies comparing the amount of LPS before and after the use of Ca(OH)2 as ICM in infected root canals were included. Risks of bias assessment and data extraction were performed. Meta-analysis was conducted by sub-grouping according to Ca(OH)2, presence of antimicrobial substance (AS), irrigant solution during chemomechanical preparation (CMP) and incidence of LPS reduction. Certainty of evidence determined by GRADE. Results Nine studies were included in qualitative synthesis and seven in meta-analysis. Three papers had low risk of bias (RB), one had moderate RB , two had high RB, and three ‘some concerns’ RB. Overall, Ca(OH)2, with or without AS, reduced mean LPS before CMP (SMD −1.087 [−1.453, −0.721], p Conclusions Ca(OH)2 reduces endotoxin levels when used as ICM, but is unable to eliminate LPS completely, independent of the irrigating solution used, with very low certainty of evidence.