Effect of different methods of working length determination on the quality of obturation and postoperative pain following pulpectomy in primary molars: a comparative randomized clinical trial.

One of the key factors influencing the success of a pulpectomy is the accurate determination of the root canal's working length, followed by the quality of obturation and postoperative pain. Incorrect working length can result in incomplete cleaning and apical leakage or apical perforation and under- or overfilling, and increasing the incidence of postoperative pain. The aim of the study was to evaluate the effect of different methods of working length determination on the quality of obturation and postoperative pain in pulpectomized primary molars. A comparative randomized clinical trial was conducted involving 120 children aged 4-7 years requiring primary molar pulpectomy. Participants were allocated into three groups based on the method used to determine the working length of the root canals: CR (conventional radiography), DR (digital radiovisiography), and EAL (electronic apex locator). All pulpectomy procedures were performed by a single operator, except for working length determination. The quality of obturation was categorized as underfilled, optimally filled, or overfilled, while postoperative pain was assessed using a four-point pain scale. The collected data were analyzed using a one-way ANOVA test, followed by Tukey's post hoc test, the Chi-square test, and an unadjusted logistic regression model. The highest percentage of optimally filled root canals was observed in the EAL group (82.5%), followed by the DR group (72.5%) and the CR group (62.5%). Additionally, children in the CR group experienced significantly greater postoperative pain compared to those in the DR and EAL groups at 6, 12, 24, and 48 h post-treatment. The utilization of an electronic apex locator resulted in a greater proportion of optimally filled canals and reduced postoperative pain. Furthermore, pairwise comparisons of the WLD methods within the model revealed associations that were clinically relevant and approached statistical significance with respect to either the quality of obturation or the incidence of postoperative pain.