Prognosis of root canal treatment in teeth with preoperative apical periodontitis: a study with cone-beam computed tomography and digital periapical radiography.

The findings of this study suggest that several tooth- and treatment-related predictor variables, including tooth location, periapical radiolucency size, quality of the coronal restoration, magnification/illumination, disinfection of gutta-percha, time elapsed to definitive coronal restoration, as well as, the density of root canal filling may act strongly and independently for determining the root canal treatment outcome in teeth with pre-therapeutic apical periodontitis.