Abstract
Aim: To evaluate the influence of three different working lengths on the amount of apically extruded debris. Methodology: Thirty lower premolars with single roots and straight root canals were standardized at 17 mm. Then, they were inserted into Eppendorf tubes, and the 1.5% agar gel was introduced into the tubes surrounding the roots. The coronal section of the roots was kept visible. The set of tubes and agar gel was weighed 3 times and the average value was recorded. Then, the specimens were randomly distributed in 3 different groups according to the working length (CT) used for the instrumentation: Group (CT -1) - the working length 1 mm below the major foramen (MF); Group (CT 00) - the length was determined at the MF, and Group (CT +1) - the CT was determined 1 mm beyond the MF. Instrumentation was performed with Reciproc Blue R25 (VDW, Munich, Germany) under irrigation with 0.9% saline. After preparation, samples were removed from Eppendorf tubes and weighed 3 times again. The difference between the mean values of the initial and final weight was recorded. The one-way ANOVA test (post-hoc Bonferroni) was used with P> 0.05. Results: The average weight of the extruded waste was 0.0134 ± 0.0157 for CT -1, 0.0075 ± 0.0062 for CT 00 and 0.0075 ± 0.0068 for CT +1, with no statistically significant differences between groups. Conclusion: There was no impact of the different CTs on the amount of extruded debris beyond the apex.
Highlights
The working length (WL) determines where the root canal should be instrumented and obturated
Suggest that the WL should be set at the limit of the major foramen (MF), allowing the cleaning of the canal, encompassing both dentinal and cemental canals (De Souza Filho, et al, 1987)
By instrumenting the canal beyond the traditional 1 mm short of the apex, there is a cleaning of the MF and an enlargement of the preparation in the apical third
Summary
The working length (WL) determines where the root canal should be instrumented and obturated. This determination is set 1 mm short of the radiographic apex, aiming the instrumentation solely at the dentinal canal rather than its full extension (Ricucci et al, 2016). By instrumenting the canal beyond the traditional 1 mm short of the apex, there is a cleaning of the MF and an enlargement of the preparation in the apical third. One possible drawback of the foraminal cleaning is the risk of increasing postoperative pain, mainly when sodium hypochlorite is used as irrigant (Cruz Junior et al, 2016). The risk of the cytotoxic effects of NaOCl beyond the apex is minimized
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
