Do Calcium Chelators Play a Role in the Removal of Calcium Hydroxide From Root Canals? A Systematic Review of Laboratory Studies

OBJECTIVE: To identify whether root canal irrigants with calcium chelation ability play a role in the removal of calcium hydroxide (CH) from the root canals when compared to non-chelators. METHODS: The protocol is registered in the Open Science Framework registry (doi 10.17605/OSF.IO/CHG2Q). PubMed, Scopus, Embase, Cochrane Library, ProQuest, Google Scholar, Science direct and open grey databases were searched until March 2021. Laboratory studies comparing the effectiveness of calcium chelators in the removal of CH with non-chelators delivered using needle irrigation, irrigation agitation or instrumentation techniques were included. The quality of included studies was appraised using a modified Joanna Briggs Institute critical appraisal checklist for a randomised clinical trial. Two independent reviewers were involved in study selection, data extraction, appraising the quality of studies. Any disagreements were resolved by a third reviewer. RESULTS: The current review included 17 studies, with 16 being of "moderate" quality and one of "low" quality. Due to methodological differences within the included studies, quantitative analysis was not performed. Laboratory studies were only included in the current review because no clinical study exists on this topic. Evidence from the review indicates that calcium chelators are superior to non-chelators in the removal of CH when used with needle irrigation, passive ultrasonic irrigation and instrumentation techniques. CONCLUSION: Calcium chelators are superior in the removal of CH from the root canal system over non-chelators.