Objectives: This systematic review (SR) aimed to investigate the influence of obturation extent on the final outcome of root canal treatment (RCT), by answering the question "among patients requiring RCT on fully formed permanent teeth, is there an association between obturation extent and the final treatment outcome?"
Materials and methods: Five electronic databases and three gray literature searches were performed. Observational studies investigating the association between obturation extent and RCT outcome in fully formed permanent teeth with a minimum follow-up of 12 months were included. We evaluated the risk of bias (RoB) in with MAStARI for cohort studies. The overall quality of the evidence was assessed with the GRADE-tool.
Results: Twenty-two studies were included, 2 had high RoB, 7 moderate RoB, and 13 low RoB. Underextended obturation demonstrated increased odds of an unfavorable outcome in seven studies, in which the odds varied between 6.94 (95%CI 2.20-21.87) and 1.73 (95%CI 1.02-2.95). Overextended obturation also demonstrated this association in four studies, with odds varying from 1.90 (95%CI 1.23-2.94) to 23.00 (95%CI 5.58-94.75). Due to heterogeneity and the very low level of evidence found in the GRADE analysis, the results from this SR should be interpreted with caution.
Conclusions: Obturation extent seems to influence RCT outcome; overextended and underextended obturations showed higher chance of association with less favorable outcomes than adequate obturation; however, this association was not categorically supported.
Clinical relevance: This SR provides information about obturation extent influence on RCT outcome and guides clinicians to make evidence-based decisions during endodontic practice.
Keywords: Periapical tissue; Root canal obturation; Systematic review; Tooth apex.