Outcome of root canal retreatment filled with gutta-percha techniques: A systematic review and meta-analysis.

Objective: The present systematic review and meta-analysis aimed to evaluate the success rate of root canal retreatment filled with gutta-percha and the variables related to retreatment success.
Data: The PRISMA guidelines were followed for the present review. The study protocol was registered in the International Prospective Database of Systematic Reviews (PROSPERO CRD42021283134). Risk assessment was performed using the Newcastle-Ottawa scale. Funnel plots were used to detect publication bias and asymmetry was assessed using Egger's tests.
Sources: PubMed, Scopus, ScienceDirect, Cochrane, and additional sources were searched.
Study Selection: Studies published until 10 December 2022. Clinical studies evaluating the success of root canal retreatment filled with gutta-percha with at least a 1-year follow-up were selected.
Results: Ten studies and one unpublished study fulfilled the inclusion criteria for quantitative analysis. The success rate of non-surgical root canal retreatment was 71% (95% CI: 66%-76%) with strict criteria and 87% (79% - 93%) with loose criteria for 1-3 years of follow-up, and 77% (66% - 86%) with strict criteria for a 4-5 years of follow-up. Endodontically retreated teeth with periapical lesions had a lower success rate under strict criteria. The tooth type, dental arch, initial periapical index (PAI) score, and the number of visits also affected the treatment success rate under strict criteria. For the loose criteria, teeth with larger periapical lesions and higher initial PAI scores had a lower success rate.
Conclusions: According to the present systematic review and meta-analysis, non-surgical root canal retreatment results in favourable outcomes. The presence of a periapical radiolucency, periapical lesions >5mm, a higher initial PAI score, multiple-visit retreatments, and mandibular and molar teeth resulted in a lower success rate.
Clinical Significance: Non-surgical root canal retreatment filled with gutta-percha techniques is a relatively predictable procedure with a high success rate. Several variables can affect retreatment success, mainly the presence and size of a periapical lesion and the type of tooth.
Competing Interests: Declaration of competing interest The authors of this review received no financial support and declare no potential conflicts of interest with respect to the authorship and/or publication of this article.
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