Comparative analysis of standardization of three calibration endodontic rulers

Objective: This study aimed to evaluate the accuracy of different calibration endodontic rulers used for calibration of gutta-percha cones. Methods: Three hundred and sixty gutta-percha cones were calibrated by three different calibration endodontic rulers ( ngelus , Prisma and Maillefer ) in the holes #25, #30, #35, #40, #45 and #50. The diameter of the calibrated end of each cone was measured by two examiners using a digital caliper. Data were organized into a table and statistically analyzed with ANOVA and Bonferroni test with a significance level of 5%. Results: The bestcalibration results were obtained by Prisma (0.023 mm ± 0.002 mm), while the others presented the worst results of calibration with no statistical difference between them: ngelus (0.028 mm ± 0.002 mm) and Maillefer (0.030 mm ± 0.002 mm). Conclusion: It can be concluded that the rule Prisma had on average a higher result in the standardization of gutta-percha cones, followed by ngelus and Maillefer .