Prevalence and extent of long oval canals in the apical third

Computed tomography evaluation of rotary systems on the root canal transportation and centering ability

“…This result differs from previous studies that indicate that the apical segment usually has more canal transportation toward the outside of the curve. 19,22,25 As in the present study, an average deviation from the direction of the different thirds was used, and hence our results probably reflect the higher incidence of deviation inside of the curve that occurs in the cervical and middle segments, as previously reported by Stavileci et al 9 An important difference between the NiTi systems used in the present study is related to the number of the files used. ProTaper and Twisted File systems use a small number of files in an attempt to simplify the root canal instrumentation, whereas Hero and Liberator systems allow the use of a larger number of instruments.…”

“…ProTaper and Twisted File systems use a small number of files in an attempt to simplify the root canal instrumentation, whereas Hero and Liberator systems allow the use of a larger number of instruments. Since the anatomic diameter at 1 mm from the apex of the mesiobuccal root is around 0.22 mm and 0.43 mm in mesial-distal and buccal-lingual directions, respectively, 22 Hero and Liberator systems provide further enlargement in the third apical dentine removal, which is greater in this region compared to the final instrument of the ProTaper and Twisted File. Although Hero and Liberator instrumentation results in a larger apical diameter, the transportation values obtained with these instruments were similar to those obtained with the ProTaper and Twisted File systems.…”

“…Previous reports already clarify that canal transportation can be considered a procedural error resulting in lower efficiency of preparation techniques due to inadequate root canal cleaning and the persistency of periapical lesions. 21 In this sense, Wu et al 22 reported that apical transportation of more than 0.3 mm could negatively affect the sealability of filling material. In the present study the shaping ability of all groups was similar, considering the apical transportation and centering ability values in which none of the rotary systems used reached apical transportation greater than 0.2 mm.…”

A comparison of techniques for obturating oval-shaped root canals

“…[2][3][4][5] was confirmed in this study. Findings revealed that only the apical third exhibited a consistently smooth, round shape 1,13) . Therefore, obturation of oval canals depended to a considerable extent on sealer cement or on the Thermafil group that permitted the flow of gutta-percha into unprepared recesses of the canal.…”

“…Oval-orribbon-shapedcanalsoccurinapproximately 25% of teeth 1) . The preparation and obturation of these canals pose a challenge.…”