Prospective longitudinal studies of sodium hypochlorite or chlorhexidine used against Enterococcus faecalis identified in endodontic infections, before or after root canal preparation, were eligible for inclusion. Literature reviews and case reports were excluded. Studies were required to be of human participants, who had nonsurgical root canal treatment performed during the study. Participants were required to have a non-contributory medical history and to have microbiological samples collected before and after root canal preparation. Studies were excluded if they were in vitro or animal studies or if they involved primary teeth.
All the included studies used between 0.5% and 2.5% sodium hypochlorite as an irrigant. Baseline infections were primary in one study, secondary in three studies, and mixed in one study. Enterococcus faecalis was detected in teeth using polymerase chain reaction (PCR) in three studies and culture in all five studies.
Two reviewers independently selected studies for inclusion.