roots C.E. - the international magazine of endodontology

I C.E. article_ instrumentation and obturation Canal preparation and obturation: An updated view of the two pillars of nonsurgical endodontics Author_Ove A. Peters, DMD, MS, PHD _The ultimate goal of endodontic treatment is the long-term retention in function of teeth with pulpal or periapical pathosis. Depending on the diagnosis, this therapy typically involves the preparation and obturation of all root canals. Both steps are critical to an optimal long-term outcome. This article is intended to update clinicians on the current understanding of best practices in the two pillars of nonsurgical endodontics, canal preparation and obturation, and to highlight strategies for decision making in both uncomplicated and more difficult endo- dontic cases. Prior to initiating therapy, a clinician must establish a diagnosis, take a thorough patient history and conduct clinical tests. Recently, judi- cious use of cone-beam computed tomography (CBCT) has augmented the clinically available imaging modalities. Verifying the mental image of canal anatomy goes a long way to promote success in canal preparation. For example, a missed canal frequently is associated with endo- dontic failures.1 As most maxillary molars have two canals in the mesiobuccal root, case referral to an en- dodontist for microscope-supported treatment should be considered. Endodontists are increas- ingly using CBCT and the operating microscope to diagnose and treat anatomically challenging teeth, such as those with unusual root anatomies, congenital variants or iatrogenic alteration. The endodontic specialist, using appropriate strate- gies, can achieve good outcomes even in cases with significant challenges (Fig. 1). _Preparation of the endodontic space The goal of canal preparation is to provide ad- equate access for disinfecting solutions without making major preparation errors such as perfora- tions, canal transportations, instrument fractures or unnecessary removal of tooth structure. The introduction of nickel-titanium (NiTi) instruments to endodontics almost two decades ago2 has resulted in dramatic improvements for successful canal prepa- ration for generalists and specialists. Today there are more than 50 canal preparation systems; however, not every instrument system is suitable for every clinician and not all cases lend themselves to rotary preparation. Several key factors have added versatility in this regard, for example, the emergence of special designs such as orifice shapers and mechanized glide path files. Another recent development is the applica- tion of heat treatment to NiTi alloy, both before and after the file is manufactured. Deeper knowledge of metallurgical properties is desirable for clinicians who want to capitalize on these new alloys. Finally, more recent strategies such as minimally invasive endodontics have emerged.3 _Basic nickel titanium metallurgy What makes NiTi so special? It is highly resistant to corrosion and, more importantly, it is highly elastic and fracture-resistant. NiTi exists reversibly in two conformations, martensite and austenite, depending on external tension and ambient temperature. While steel allows 3 percent elastic deformation, NiTi in the _c.e. credit This article qualifies for C.E. credit. To take the C.E. quiz, log on to www.dtstudyclub.com. Click on ‘C.E. articles’ and search for this edition (Roots C.E. Magazine — 1/2017). If you are not registered with the site, you will be asked to do so before taking the quiz. You may also access the quiz by using the QR code below. 06 I roots 1_ 2017

roots C.E. - the international magazine of endodontology

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