Root canal therapy requires the clinician to carefully satisfy a host of requisites through each phase (e.g., access, preparation, disinfection, and obturation, sealing) of treatment. As Dr. Gary Glassman explains in Part 1 of his four-part virtual training series on endodontic therapy, not only does the process require diligent examination, shaping, and disinfection, but no two therapies are the same. This becomes a factor due to the differing anatomy of teeth in patient’s mouths. For some, this may come as a great challenge, working with what is present and tackling it through the necessary precautions and treatment. Dental students and practitioners know that several complications often come into play, including:
Calcifying Root Canals
Sometimes calcium deposits make a canal too narrow for endodontic instruments to reach the apex of the root. If teeth have this calcification, the practitioner may perform endodontic surgery to clean and seal the remainder of the canal.1 Calcified root canals can be caused by a whole host of reasons, such as caries, trauma or infection, drugs, or simply because of the natural aging of the tooth.2
Obstructions and Ledges
Instrument obstruction is another common obstacle to successful endodontic therapy. Because of complications such as calcified root canals, sometimes a practitioner does not have both a good visual and/or physical space to achieve the intended access into the root canal. This leads to the stubborn approach of forcing therapy, which may lead to broken or fractured instruments. However, there are many approaches, such as proper radiography and pre-curved files, that can be used around these obstructions.3 If the practitioner is unsure about access, then alternatives should be the main focus.
Soft or hard tissue blockages can present clinical challenges as well. A ledge is created when the working length can no longer be negotiated and the original pathway of the canal has been lost. Don’t force the instruments by instead using passive step-back and balanced force techniques, instrumenting the canal to its full length to help prevent ledge formation.4
Though a real challenge, finding the MB2 canal in endodontic treatment means that you have finally arrived as a clinician. More often than not, the MB2 is identified in maxillary first molars, and being able to clean the root canal system here is of the utmost importance. Patient examination is critical here, with steps that include checking for apical palpations as well as sensitivities to biting, percussions, and on/off swelling. Three-dimensional (3D) imaging provides optimal evidence of the canal location, and provides the practitioner with sufficient information to begin treating the canal. The future of 3D imaging, therefore, looks very bright for endodontic treatment.5
While root canal therapy can often be complex, dental students know that such difficulties are expected. The obstacles and hurdles that are common with the treatment provide a challenge that requires focus, patience, and much, much practice. Endodontic therapy requires diligence and repetition, but can be rewarding as one's skills and experience develop over time. Building one’s skills is key in all aspects of dentistry, but for the endodontic specialty, it’s even more so. If you treat endodontics with the right mindset, you’ll be more confident in performing consistent root canal therapy.
 Krasner P, Rankow HJ, Abrams ES. Access opening and canal location. Endodontics Colleagues for Excellence. 2010. https://www.aae.org/uploadedfiles/publications_and_research/endodontics_colleagues_for_excellence_newsletter/ecfespring2010_final.pdf. Accessed December 27, 2016.
 Garg N, Garg A. Cleaning and shaping of the root canal system. In: Textbook of Endodontics. Westminster, London, England: JP Medical Ltd; 2013:277.
 Carrotte P. Endodontic problems. Brit Dent J. February 2005:127-133.
 Jafarzadeh H, Abbott PV. Ledge formation: Review of a great challenge in endodontics. J Endo 2007;33(10):1155-1162. https://www.ncbi.nlm.nih.gov/pubmed/17889681. Accessed December 21, 2016. Glassman G. Advances in Endodontic Treatment: Part 1--Diagnosis and Treatment Planning. https://www.youtube.com/watch?v=0NWBVwF-vek&t=1410s. Accessed December 21, 2016.