12 www.pagd.org Q dentistry issues let’s call this the “landing zone” so we don’t confuse this with the coronal portion of establishing the glide path.) The landing zone is the final part of the root canal preparation and is where most of the problems arise if you haven’t done everything properly up to this point. For example, if you haven’t established a working length, you will either compact debris into the apex, or you will go out the end. If you don’t establish a larger diameter final obturator then you will be relying on sealer to fill in the voids at the terminus. Only after you’ve instrumented to the apical terminus (and not out) should you feel confident in beginning the obturation. By obturation, I also mean flushing the canal with EDTA and then NaOCl. EDTA is a mild acid that chelates calcium and other metals and is designed to dissolve the smear layer and open up access to the lateral canals, isthmuses that you were unable to instrument into, and the plug at the end. One minute of EDTA is all that is required, and the concentration doesn’t matter, so the lowest concentration is therefore the choice. After the inorganic components are dissolved, there are still organic components including bacteria that require dissolution. A side-port syringe to introduce it is best to ensure there is no forceful extrusion beyond the apex. Agitation with an ultrasonic as well as heating NaOCl have been shown to increase the bacteriocidal effects over 100 fold. I personally fear pushing it out the apex so I hand instrument to within 2mm of the apex using my working length and then allow it to set five minutes. Afterward thorough drying with paper points, application of sealer, and placement of the gutta percha are the final steps. I hope these methods and concepts help you improve the endodontic success of your practice. I welcome comments and suggestions that have helped you in your practice as well. References 1. I Peter 4:8 Amplified Bible 2. Sen, Bilge Hakan & Ertürk, Ozlem & Pişkin, Beyser. (2009). The effect of different concentrations of EDTA on instrumented root canal walls. Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 108. 622-7. 10.1016/j.tripleo.2009.04.042. 3. Calt S, Serper A. Time-dependent effects of EDTA on dentin structures. J Endod. 2002 Jan;28(1):17-9. doi: 10.1097/00004770-200201000-00004. PMID: 11806642. 4. Teixeira CS, Felippe MC, Felippe WT. The effect of application time of EDTA and NaOCl on intracanal smear layer removal: an SEM analysis. Int Endod J. 2005 May;38(5):285-90. doi: 10.1111/j.1365-2591.2005.00930.x. PMID: 15876291. 5. Mahajan, Pardeep, Prashant Monga, Nikhil Bahunguna, and Nitika Bajaj. “Principles of Management of Calcified Canals.” Indian Journal of Dental Sciences 2 (2010). 6. https://www.dentaljuce.com/endodontics-initial-negotiationof-narrow-and-blocked-canals 7. Simon S, Machtou P, Adams N, Tomson P, Lumley P. Apical limit and working length in endodontics. Dent Update. 2009 Apr;36(3):146-50, 153. doi: 10.12968/denu.2009.36.3.146. PMID: 19480102. 8. Iqbal A. The Factors Responsible for Endodontic Treatment Failure in the Permanent Dentitions of the Patients Reported to the College of Dentistry, the University of Aljouf, Kingdom of Saudi Arabia. J Clin Diagn Res. 2016 May;10(5):ZC146-8. doi: 10.7860/JCDR/2016/14272.7884. Epub 2016 May 1. PMID: 27437351; PMCID: PMC4948527. 9. Tabassum S, Khan FR. Failure of endodontic treatment: The usual suspects. Eur J Dent. 2016 Jan-Mar;10(1):144-147. doi: 10.4103/1305-7456.175682. PMID: 27011754; PMCID: PMC4784145. 10. Mustafa, M; Almuhaiza, M; Alamri, HM; Abdulwahed, A; Alghomlas, ZI1; Alothman, TA2; Alhajri, FF3. Evaluation of the Causes of Failure of Root Canal Treatment among Patients in the City of Al-Kharj, Saudi Arabia. Nigerian Journal of Clinical Practice 24(4):p 621-628, April 2021. | DOI: 10.4103/njcp.njcp_290_20 11. Siqueira JF Jr. Aetiology of root canal treatment failure: why well-treated teeth can fail. Int Endod J. 2001 Jan;34(1):1-10. doi: 10.1046/j.1365-2591.2001.00396.x. PMID: 11307374. 12. Gillen BM, Looney SW, Gu LS, Loushine BA, Weller RN, Loushine RJ, Pashley DH, Tay FR. Impact of the quality of coronal restoration versus the quality of root canal fillings on success of root canal treatment: a systematic review and meta-analysis. J Endod. 2011 Jul;37(7):895-902. doi: 10.1016/j.joen.2011.04.002. Epub 2011 May 24. PMID: 21689541; PMCID: PMC3815527. 13. Yaylali IE, Kurnaz S, Tunca YM. Maintaining Apical Patency Does Not Increase Postoperative Pain in Molars with Necrotic Pulp and Apical Periodontitis: A Randomized Controlled Trial. J Endod. 2018 Mar;44(3):335-340. doi: 10.1016/j.joen.2017.11.013. Epub 2018 Jan 19. PMID: 29370942. 14. Shubham, S., Nepal, M., Mishra, R. et al. Influence of maintaining apical patency in post-endodontic pain. BMC Oral Health 21, 284 (2021).
RkJQdWJsaXNoZXIy MTY1NDIzOQ==