Avaliação do volume remanescente de material obturador em molares retratados com diferentes sistemas: estudo ex vivo em TCFC

Abstract

Bacteria and their toxins play an important role in the etiology and progression of pulp and periapical inflammation; therefore, root canal therapy becomes necessary. After the failure of primary endodontic treatment, the first option is non-surgical retreatment. Thus, the aim of this study was to compare the effectiveness of different retreatment techniques in removing root filling material in maxillary molars using cone-beam computed tomography (CBCT) images with high resolution. Forty extracted first maxillary molars were endodontically treated with rotary instruments, obturated, and subjected to CBCT. For retreatment, ProTaper-R (PR) and WaveOne Gold (WOG) systems with and without solvent were used for removing the root filling material. After reinstrumentation, new CBCT images were obtained with and without the use of the metal artifact reduction (MAR) tool using the same parameters. The images were qualitatively analyzed by two evaluators for the identification and location (root third) of the remaining material. For quantitative evaluation, the volume of remaining material was calculated using ITK-SNAP® software. In R software, mixed logistic and linear regression models were used to check associations between variables (p<0.05). More than half of the teeth (66.7%) had only 3 canals, and of the 130 canals, more than half (64%) had remaining root filling material. The removal of root filling material using the WaveOne Gold system was more efficient compared to ProTaper-R. Regarding the solvent, in the ProTaper-R system, the volume of remaining material without solvent was greater than the volume identified with solvent. In the WaveOne Gold system, the difference was not significant. The MAR tool did not influence the assessment of remaining material in the CBCT exam. It was concluded that the removal of root filling material in maxillary molars was more efficient with the WaveOne Gold system. The volumetric analysis using ITK-SNAP® was also noticeably important, as it allowed visualization of the volume of remaining material according to the system used.