Cone-beam computed tomography analysis of curved root canals after mechanical preparation with three nickel-titanium rotary instruments

Abstract

Cone beam computed tomography is a 3-dimensional high resolution imaging method. The purpose of this study was to compare the effects of 3 different NiTi rotary instruments used to prepare curved root canals on the final shape of the curved canals and total amount of root canal transportation by using cone-beam computed tomography. A total of 81 mesial root canals from 42 extracted human mandibular molars, with a curvature ranging from 15 to 45 degrees, were selected. Canals were randomly divided into 3 groups of 27 each. After preparation with Protaper, Revo-S and Hero Shaper, the amount of transportation and centering ability that occurred were assessed by using cone beam computed tomography. Utilizing pre- and post-instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Canals were metrically assessed for changes (surface area, changes in curvature and transportation) during canal preparation by using software SimPlant; instrument failures were also recorded. Mean total widths and outer and inner width measurements were determined on each central canal path and differences were statistically analyzed. The results showed that all instruments maintained the original canal curvature well with no significant differences between the different files (P = 0.226). During preparation there was failure of only one file (the protaper group). In conclusion, under the conditions of this study, all instruments maintained the original canal curvature well and were safe to use. Areas of uninstrumented root canal wall were left in all regions using the various systems.

Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-file Systems

“…Each sample was inserted into the unset acrylic resin so that its long axis was parallel to the long axis of the mold to ensure standardization of the specimens for tomographic imaging. 10 …”

“…D2 was the measurement of the quantity of voxels from the external surface of the distal portion of the root to the distal surface of the canal after instrumentation ( Figs 1 and 2 ). 10 …”

“…When this value was closer to zero, it implied that the instrument had a lower capacity to maintain itself in the central axis of the canal. 10 …”

A comparative evaluation of the increase in root canal surface area and canal transportation in curved root canals by three rotary systems: A cone-beam computed tomographic study

“…Cone beam computed tomography (CBCT) is a recent advancement with advantages of image accuracy, acquisition of images in three planes (coronal, sagittal and axial) and reduced image artifacts. [ 9 10 11 ]…”

Root canal segmentation in cone-beam computed tomography

“…Regarding the segmentation performed on CBCT images, the results showed that, when compared to the gold standard, both the "automatic CBCT" and "visual CBCT" were statistically different compared to the gold standard, revealing a limitation of the accurate determination of root canal volume using this image modality (with acquisition parameters used in this study). Despite the accuracy of CBCT in allowing a three-dimensional and detailed view of bone 3,22 , in this study, it did not allow a precise determination of root canal volume. This may be probably explained by the specific acquisition parameters and resolution of the CBCT used.…”