Evaluation of the adhesivity of the resin sealer to the intraradicular dentin by computed microtomography during the push-out test

• Grant number: 13/10151-6
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2013
• End date: July 31, 2015
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Manoel Damiao de Sousa Neto
• Grantee: Manoel Damiao de Sousa Neto
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The aim of this study is to evaluate the adhesiveness of the Real Seal XT to the intraradicular dentin through the push-out test, and his failures using computed microtomography (micro-CT). Forty-five human canines were selected and crowns removed leaving the roots with 15 mm length. Root canals were instrumented with Reciproc System (R50 file) and irrigation was performed with 1% sodium hypochlorite solution. Then the channels were filled with 5 mL of 17% EDTA for 3 minutes, followed by irrigation with 5 mL of distilled water and dried with absorbent paper points. Samples were randomly divided into three groups according the sealer: G1 (n = 15) - RealSeal XT, G2 (n = 15) - Epiphany SE and G3 (n = 15) - AH Plus. The cement was handled according to the manufacturer's instructions and inserted into the root canals with a lentulo spiral. Radiographs at different angles were performed to verify the absence of voids in fillings. The samples were stored at 37 ° C and 100% humidity during a period three times longer than the setting time of the cement. After this period, 12 samples in each group were sectioned obtaining slice thicknesses of 1-mm (three for every third: coronal, medium and apical) that were tested with the push-out test. The other three samples (nine slices for every third) in each group were analyzed by the Scanning electron microscope (SEM). The push-out test was conducted through a device equipped with a load cell and coupled to the micro-CT, where it was generated a load graph (MPa) of x for displacement (mm) or tension x for deformation. During the tests the samples could be scanned anytime. The reconstruction and retrieval of the three-dimensional models was performed by qualitative analysis in the cervical, middle and apical thirds to verify the location of the fracture line in relation to the obturator paste and root dentin (dentin/obturation paste, cone/cement), and the quantitative analysis of the extent in mm. Because it is a fixed dispositive with a static position, it was possible to compare the specimen before and after the test due to the overlap of the three-dimensional models. Data from the bond strength from the push-out test were statistically analyzed. (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)

BRITO-JUNIOR, MANOEL; LEONI, GRAZIELA BIANCHI; PEREIRA, RODRIGO DANTAS; FARIA-E-SILVA, ANDRE LUIS; GOMES, ERICA ALVES; SILVA-SOUSA, YARA TERESINHA; SOUSA-NETO, MANOEL DAMIAO. A Novel Dentin Push-out Bond Strength Model That Uses Micro-Computed Tomography. JOURNAL OF ENDODONTICS, v. 41, n. 12, p. 2058-2063, DEC 2015. (09/09989-0, 13/10151-6)