Influence of Cone-beam Computed Tomography on Endodontic Retreatment Strategies among General Dental Practitioners and Endodontists Gustavo Rodr  ıguez, DDS, MSc,* Shanon Patel, BDS, MSc, † Fernando Dur  an-Sindreu, DDS, PhD,* Miguel Roig, DDS, PhD,* and Francesc Abella, DDS, PhD* Abstract Introduction: Treatment options for endodontic failure include nonsurgical or surgical endodontic retreatment, intentional replantation, and extraction with or without replacement of the tooth. The aim of the present study was to determine the impact of cone-beam computed tomographic (CBCT) imaging on clinical decision making among general dental practitioners and endodontists af- ter failed root canal treatment. A second objective was to assess the self-reported level of difficulty in making a treatment choice before and after viewing a preopera- tive CBCT scan. Methods: Eight patients with endodon- tically treated teeth diagnosed as symptomatic apical periodontitis, acute apical abscess, or chronic apical abscess were selected. In the first session, the exam- iners were given the details of each case, including any relevant radiographs, and were asked to choose 1 of the proposed treatment alternatives and assess the difficulty of making a decision. One month later, the ex- aminers reviewed randomly the same 8 cases with the additional information from the CBCT data. Results: The examiners altered their treatment plan after viewing the CBCT scan in 49.8% of the cases. A significant dif- ference in the treatment plan between the 2 imaging modalities was recorded for endodontists and general practitioners (P < .05). After CBCT evaluation, neither group altered their self-reported level of difficulty when choosing a treatment plan (P = .0524). The extrac- tion option rose significantly to 20% after viewing the CBCT scan (P < .05). Conclusions: CBCT imaging directly influences endodontic retreatment strategies among general dental practitioners and endodontists. (J Endod 2017;-:1–5) Key Words Cone-beam computed tomographic imaging, decision making, endodontists, general dental practitioners, retreatment strategies C linical decision mak- ing to reach the most suitable treatment choice is a complex process that involves consideration of the best available evi- dence, case-specific clin- ical judgment, and patient preferences (1). However, treatment decisions are usually made with some degree of uncertainty. Treatment de- cisions can vary widely among general dental practitioners and dental specialists (1–3) and are dependent on level training, clinical experience, attitudes and values of persons involved, and economic resources (4). Several studies have shown that success rates of primary nonsurgical root canal treatment generally approach 90% (5–7). Given the anatomic complexity of root canal systems, intricate and resilient pathogenic microbial communities, inherent limitations of chemomechanical instrumentation and obturation methods, and leakage of permanent restorations, complete elimination of bacteria from the root canal systems is not achievable (8, 9). Therefore, it is inevitable that some initial root canal treatments fail. Clinicians are often faced with 3 treatment modalities for teeth with periapical dis- ease: nonsurgical retreatment, endodontic surgery, or extraction and replacement with an implant-supported crown (10). Long-term survival rates for restored single-tooth implants and teeth with nonsurgical root canal treatment are remarkably similar (11–14). Over the past decade, considerable advances have been made not only in single-tooth implants but also in surgical endodontic treatment. Recent meta-analyses indicate that modern endodontic microsurgery is more successful than traditional endodontic surgery (15, 16). Tsesis et al (17) evaluated the outcome of contemporary periapical microsurgery and concluded that there was a 91.6% suc- cess rate 1 year postoperatively. Another possible treatment option in certain cases of endodontic failure is intentional replantation. A recent study on intentional replantation using contemporary materials showed an 88% mean survival rate (18). Thus, the decision to perform endodontic or implant treatment should not be based only on treatment outcome (11). Conventional periapical (PA) radiography has been used for many years as a diag- nostic aid in endodontics. However, it is well established that PA radiographs are not as accurate as cone-beam computed tomographic (CBCT) imaging in detecting the From the *Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Sant Cugat del Vall es, Barcelona, Spain; and † Department of Conservative Dentistry, King’s College London Dental Institute, London, UK. Address requests for reprints to Dr Francesc Abella, Dentistry Faculty, Universitat Internacional de Catalunya, C/Josep Trueta s/n, Sant Cugat del Vall es 08195. E-mail address: franabella@uic.es 0099-2399/$ - see front matter Copyright ª 2017 American Association of Endodontists. http://dx.doi.org/10.1016/j.joen.2017.04.004 Significance A CBCT scan should only be considered in cases of abnormal findings on PA radiography and/or mod- erate to high difficulty. Our findings show that end- odontic retreatment strategies may be directly influenced by information gained from a CBCT scan. Clinical Research JOE — Volume -, Number -, - 2017 Cone-beam Computed Tomography in Endodontic Retreatment Strategies 1