Evaluation of the internal anatomy, instrumentation and retreatment techniques, using new mechanized instrumentation systems on permanent mandibulary second molars with fused roots

• Grant number: 14/03009-1
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): June 01, 2014
• Effective date (End): May 31, 2016
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Cooperation agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal researcher: Ivaldo Gomes de Moraes
• Grantee: Pablo Andrés Amoroso Silva
• Home Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The knowledge of the internal anatomy of the teeth and their possible anatomical variations are important for clinical success of endodontic treatment. The fusion of the roots of the second molars may occur more frequently than in other dental groups, leaving an anatomical feature known as "C" shaped canal. With a sample of 88 lower second fused molars, the study aims to analyze the morphological and morphometric aspects of the internal anatomy of the root canal system of the C-shaped canals using micro computed tomography (Micro-CT). All teeth will be scanned using micro-CT system (SkyScan 1174v2; Bruker-microCT, Kontich, Belgium). The parameters to be used are 50 kV, 800 mA, 360 degrees of rotation and an isotropic resolution of 19.6 micrometers. The system includes a charge-coupled device camera producing images (1304 × 1024 pixels). Images of each sample will be reconstructed with specific software NRecon (v.1.6.3 NRecon; Bruker-microCT) providing axial cross sections of the structure of the samples. Using the program segmentation and modeling of automatic surface CTAN V.1.12 (Bruker-microCT and the software for data visualization CTVol v.2.2.1 (Bruker-microCT) the qualitative evaluation of specimens will be analyzed: area, perimeter, circularity, major diameter, minor diameter and aspect ratio. In the second phase of the study, samples will be used for evaluation before and after instrumentation with new instrumentation systems (Reciproc and SAF). After scanning the teeth with the instrumented canals all the images will be reconstructed with (NRecon v.1.6.3; Bruker-microCT) program. To evaluate area, volume remaining dentin and pre and post instrumentation of both groups, the CTAN (Bruker-microCT) program will be used. Additionally, the study aims to examine the ability of retreatment (removal of the filling material), of both instrumentation systems through Micro-CT. Once the images are reconstructed with NReconv1.6.4.8 program), the CTAN software will be used to measure the volume of material (mm3) remaining after each shutter retreatment step. For each sample, the volume of material is calculated in three levels: between 0.5 - 2.5 mm, apical, between 2.5 - 4.5 millimeters, middle third from 4.5 to 6.5 millimeters. The amount of the residual obturation material after retreatment procedure will be expressed in percentages compared with the initial volume filling of root canals. Finally, the amount of remaining sealer and the new obturation of the retreated teeth will be analyzed by confocal microscopy analysis at 2, 4 and 6 mm from the apex. The software fore measuring the remaining sealer and the new sealer an the sealer/dentin interface will be the Image J V1.46r. (National Institute of Health, USA) To obtain the of anatomical studies results, the range of the average, minimum and maximum values will be processed by Prism 5.0 (GraphPad Software Inc, La Jolla, CA, USA) software. The other results will be tested for D'Agostino and Pearson for verifying the normal distribution. In the absence of normality, the nonparametric Kruskal-Wallis will be used. If the presence of normal distribution is confirmed a parametric ANOVA test will be used. For all tests the significance level of 5% will be set. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SILVA, PABLO AMOROSO; ALCALDE, MURILO PRIORI; VIVAN, RODRIGO RICCI; HUNGARO DUARTE, MARCO ANTONIO. Comparison of the Self-Adjusting File and Hedstrom File Used as Supplementary Instruments for the Remaining Filling Material Removal During Retreatment of C-Shaped Canals: A Micro-CT Study. EUROPEAN ENDODONTIC JOURNAL, v. 5, n. 2, p. 112-117, 2020. Web of Science Citations: 0.

AMOROSO-SILVA, P.; ALCALDE, M. P.; HUNGARO DUARTE, M. A.; DE-DEUS, G.; ORDINOLA-ZAPATA, R.; FREIRE, L. G.; CAVENAGO, B. C.; DE MORAES, I. G. Effect of finishing instrumentation using NiTi hand files on volume, surface area and uninstrumented surfaces in C-shaped root canal systems. International Endodontic Journal, v. 50, n. 6, p. 604-611, JUN 2017. Web of Science Citations: 10.

AMOROSO-SILVA, PABLO ANDRES; ORDINOLA-ZAPATA, RONALD; HUNGARO DUARTE, MARCO ANTONIO; GUTMANN, JAMES L.; DEL CARPIO-PEROCHENA, ALDO; BRAMANTE, CLOVIS MONTEIRO; DE MORAES, IVALDO GOMES. Micro-computed Tomographic Analysis of Mandibular Second Molars with C-shaped Root Canals. JOURNAL OF ENDODONTICS, v. 41, n. 6, p. 890-895, JUN 2015. Web of Science Citations: 7.