Outcome of nonsurgical retreatment and endodontic microsurgery: a meta-analysis

The purpose of this study was to evaluate and compare the clinical and radiographic outcomes of nonsurgical endodontic retreatment and endodontic microsurgery by a meta-analysis. Electronic databases including PubMed, Embase, Medline, and The Cochrane Library were searched, and the references of related articles were manually searched to identify all the clinical studies that evaluated the clinical and radiographic outcomes after retreatment or microsurgery. The first and second screening processes were conducted by three reviewers independently. The final studies were selected after strict application of the inclusion and exclusion criteria. The random effects meta-analysis model with the DerSimonian-Laird pooling method was performed. The weighted pooled success rates and 95 % confidence interval estimates of the outcome were calculated. Additionally, the effects of the follow-up period and study quality were investigated by a subgroup analysis. Endodontic microsurgery and nonsurgical retreatment have stable outcomes presenting 92 and 80 % of overall pooled success rates, respectively. The microsurgery group had a significantly higher success rate than the retreatment group. When the data were organized and analyzed according to their follow-up periods, a significantly higher success rate was found for the microsurgery group in the short-term follow-up (less than 4 years), whereas no significant difference was observed in the long-term follow-up (more than 4 years). Endodontic microsurgery was confirmed as a reliable treatment option with favorable initial healing and a predictable outcome. Clinicians may consider the microsurgery as an effective way of retreatment as well as nonsurgical retreatment depending on the clinical situations.