Clinical outcomes and prognostic factors in endodontic treatment: a systematic review from 2002-2022

Objective This systematic review evaluates prognostic factors influencing the success of endodontic treatments for apical periodontitis over two decades (2002-2022), identifying key clinical variables affecting outcomes in primary and non-surgical retreatments.Materials and methods A comprehensive literature search following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was conducted in PubMed, Scopus, ScienceDirect and Embase (January 2002 to December 2022). Studies meeting strict inclusion criteria and focusing on clinical and radiographic outcomes were analysed. Risk assessment was performed using version two of the Cochrane risk-of-bias tool for randomised trials and the Newcastle-Ottawa scale for longitudinal studies. Factors evaluated included pre-operative, intra-operative and post-operative aspects.Results In total, 13 studies met the inclusion criteria. Apical periodontitis before treatment significantly reduced success rates. Other influential factors included pulp condition, lesion size and the length and quality of previous fillings. The two randomised trials showed concerns about intervention bias and underreporting, while three of eleven longitudinal studies had a moderate risk of bias.Conclusions This review emphasises the multifactorial nature of endodontic success and highlights the importance of apical periodontitis and other pre-operative factors for treatment prognosis. It suggests that a comprehensive approach considering these factors is crucial for improving treatment outcomes in endodontic practice.