The outcomes of nonsurgical root canal treatment and retreatment assessed by CBCT: a systematic review and meta-analysis.

Cone-beam computed tomography (CBCT) has been demonstrated to identify apical radiolucency with higher accuracy than two-dimensional radiography. The outcome of root canal treatment varies depending on the imaging modality employed. This systematic review aimed to: (1) estimate the success rate of nonsurgical root canal treatment and retreatment when assessed by CBCT and (2) investigate the influence of some factors suspected to be associated with treatment outcomes. An electronic search was performed in the following databases: MEDLINE, Embase, Web of Science, the Cochrane Library, and gray literature. Article selection and data extraction were independently conducted by 2 reviewers. The terms 'strict' (complete resolution of periapical lesion) or 'loose' (reduction in size of existing periapical lesion) were used to describe the outcome criteria. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to evaluate the quality of the included studies. Meta-analysis and meta-regression established pooled outcome rates, 95% confidence intervals (CIs), and significant clinical prognostic factors (P < .05). Nineteen articles were included. The overall quality of evidence was moderate. The estimated weighted pooled overall success rates for NSRCT and NSReRCT assessed by CBCT were 41.03% (95% CI: 28.68%-53.95%; I = 94.76%) under strict criteria and 85.01% (95% CI: 80.85%-88.75%; I = 68.36%) under loose criteria. This review's findings offer valuable insights to guide the design of future studies assessing root canal treatment and retreatment outcomes through CBCT. However, they should be interpreted with caution due to the retrospective and heterogeneous nature of the data. Review registration: This protocol was registered in the international prospective register of systematic reviews: the PROSPERO database (CRD42024591017). Clinical trial number: Not applicable.