Does the Etiology of Pulp Necrosis Affect Regenerative Endodontic Treatment Outcomes? A Systematic Review and Meta-analyses

To evaluate if there is a connection between the causes of pulp necrosis (eg, caries, trauma, dental anomaly) and the success of regenerative endodontic treatment.Electronic databases (PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, Embase) were searched for studies on regenerative endodontic treatment, which used both clinical and radiographic evaluation of root maturation after at least 6 months of follow-up. The search terms "necrotic pulp", "regenerative endodontic treatment", "revascularization", and "revitalization" were combined using Boolean operators. The main journals on endodontics and dental traumatology were additionally hand-searched. Studies were included if they specified the causes of pulp necrosis. The primary question under review was, "Does the cause of pulp necrosis affect the outcome of regenerative endodontic treatment?" Other factors such as tooth type, intracanal medicament, irrigation protocol, use of a collagen matrix, and the type of scaffold were evaluated for possible relation with the outcome. The risk-of-bias assessment for randomized and nonrandomized studies was performed separately, using a modified Cochrane Collaboration's tool and risk of bias in non-randomized studies of interventions-I tool, respectively. Meta-analysis was performed, when possible, between studies comparing treatment outcomes of teeth whose pulp necrosis had different etiology. The search strategy yielded 1197 items. After screening, 18 studies reporting 445 regenerative endodontic treatment cases were included.The overall success rate for 274 teeth with trauma etiology was 94.8%, for 95 teeth with dens evaginatus etiology was 93.1%, and for 24 teeth with caries etiology was 96%. No significant difference was found between the results of regenerative endodontic treatment among teeth with trauma, dens evaginatus, and caries etiology (P = .055). Meta-analysis of studies comparing teeth with caries vs dens evaginatus and those with trauma vs caries confirmed that there was no evidence for difference in outcomes.Further randomized studies specifically testing such hypothesis are needed to confirm the preliminary results of this review.