A Scoping Review of 4 Decades of Outcomes in Nonsurgical Root Canal Treatment, Nonsurgical Retreatment, and Apexification Studies—Part 2: Outcome Measures

Background Inconsistencies in definitions of endodontic outcome terminology jeopardize evaluations of proposed interventions and patient care quality. This scoping review aims to provide groundwork to develop a set of basic outcomes in endodontics. Design A comprehensive literature search for randomized controlled trials, cohort, case-control studies, or case series (≥10 patients) published after 1980 with patients aged≥10 years with any preoperative pulpal and periapical diagnosis in permanent teeth requiring non-surgical root canal treatment, retreatment, or apexification. Abstracted data on outcome assessment methods, assessors, and domains were reported after univariate and bivariate analyses. Results Treatment outcomes were evaluated radiographically (88%) or clinically (73%). While 2-dimensional radiography exceeded 3-dimensional radiography, use of the latter has increased since 2010, mostly for non-surgical retreatments. Of 19 identified outcomes, 5 were most frequent: Success (168 studies, 40%), Radiographic Healing (128 studies, 30%), Survival [of an asymptomatic tooth (48 studies, 12%), or of a procedure code in administrative databases (31 studies, 7%)], Pain Assessment (14 studies, 3%), and Quality of Life (11 studies, 3%). Clinician-centered outcomes have been most frequently studied since the 1980s (71%), in academic settings (76%), using prospective design (45%). Patient-centered outcomes were reported in 19% of studies prior to 2010 and 30% since 2010. They were more common among retrospective studies (49%). Conclusions Patient-centered outcome measures are lacking in endodontic studies. The state of available research can provide a baseline for development of a core outcome set in endodontics, which should represent the important patient-centered outcomes in conjunction with well validated clinician-centered outcomes.