Computerized Tomography Technique for the Investigation of the Maxillary First Molar Mesiobuccal Root

The aim of this paper was to review the literature about the use of computerized tomography to evaluate the presence and characteristics of the second mesiobuccal canal in the maxillary first molar. An electronic search was performed. Frequencies of the presence of second mesiobuccal canal and root anatomy characteristics were extracted from the selected studies. Pooled frequencies were calculated as weighted means. Seven articles were included. A second mesiobuccal canal was present in 59.32% of the teeth, and it was noncommunicating in 58.45% of teeth presenting the canal itself. The most common root canal morphology was single canal or two separated canals. The present paper showed that cone beam CT is a viable radiologic device for the evaluation of the mesiobuccal root of maxillary first molars. In fact, it was observed that the frequency of second mesiobuccal canal detection is similar to those presented by clinical studies or micro-CT evaluations. 1. Introduction A sound knowledge of root canal anatomy is mandatory in order to perform an adequate root canal treatment. Studies reported that failure to detect all the canals present in a root canal system was one of the causes of failure of endodontic therapy [1–6]. A number of studies that evaluated the anatomy of mesiobuccal roots of maxillary permanent first molars reported a wide range of anatomical variations [7–10]. It was hypothesized that failure to detect, debride, and fill a second mesiobuccal canal (MB2) of first permanent maxillary molars was one of the main causes of poor long-term prognosis after root canal treatment in these teeth [11, 12]. While many ex vivo studies investigated the presence of a mesiobuccal canal using canal staining, cross-sectioning, and dentine examination through magnification devices [13–15], the most used technique to investigate the anatomy of these teeth prior to an endodontic treatment is periapical radiography, which does not allow a complete detailed evaluation of the root canal anatomy [16]. Cone-beam computed tomography (CBCT) was developed in the 1990s with the aim of producing maxillofacial three-dimensional images using a lower radiation dose than conventional computed tomography (CT) [17, 18]. The characteristics of the CBCT scanning were described as well suited to the endodontic field because of the higher accuracy of the device in comparison to that of the standard CT [17, 19]. Despite the known limitations of the CBCT (scattering [20], lower resolution than conventional radiography [17, 21]), it proved to be valuable in endodontic therapy for