AIM: The present in-vitro study aims to compare the accuracy of root canal working length determination between the third generation and fourth generation electronic apex locators. MATERIAL AND METHODS: Fifty extracted single-rooted single canal teeth were selected for the study, and a definite coronal plane was prepared. Actual working length (AL) was measured using a stereomicroscope under 8X magnification. Electronic working length measurements were recorded using Root ZX (EL1) and Elements Diagnostic Unit (EL2) apex locators. One-way ANOVA test was carried out to analyse the data among the experimental groups. RESULTS: The results of the one-way ANOVA test showed that difference in the working length determined by either apex locators (EL1 and EL2) and actual length determined under a stereomicroscope (AL) was statistically not significant. The independent ‘t’ test comparing between groups EL1 and AL; and EL2 and AL showed that working length determined by either of the apex locators (EL1 and EL2) and actual length determined under a stereomicroscope (AL) was statistically not significant. CONCLUSION: In this in vitro study, the Root ZX and Elements Diagnostic Unit apex locators are equally accurate for determination of working length when compared to actual working length.

Background: Root resorption is the loss of dental hard tissues as a result of clastic activities. It might be broadly classified into external or internal resorption by the location of the resorption in relation to the root surface. the various techniques used these days for filling internal resorption include warm condensation, vertical condensation, core techniques, thermoplasticized gutta-percha, warm vertical compaction, and cold lateral condensation. Objectives: The aims and objectives of this study were to compare the quality of root fillings in artificially created internal resorption cavities filled with warm vertical compaction, lateral condensation, Obtura II along with System B, E and Q plus along with System B, and Thermafil, and to calculate the percentage of gutta-percha, sealer, and voids using an ImageJ software. Results: Results between the warm vertical compaction (group I), lateral condensation (group II), Obtura II with System B (group III), E and Q plus with System B (group IV), and Thermafil (group V), group III showed the highest percentage of gutta-percha plus sealer and gutta-percha, and least number of voids, which was statistically significant ( P < 0.000). Conclusion: It can be concluded that Obtura II along with System B was found to be the most suitable obturation technique for the management of teeth exhibiting internal resorption. Thermafil was found to give the poorest obturation quality when used to fill the teeth with internal resorption. Similarly, lateral condensation technique was observed to show maximum sealer and hence was not ideal for the management of internal resorptive cavities.