Impact of new final irrigation substances and its repercussion in bond strength of root canal sealer in root canal dentin wall

• Grant number: 12/03042-3
• Support Opportunities: Regular Research Grants
• Duration: June 01, 2012 - August 31, 2012
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Milton Carlos Kuga
• Grantee: Milton Carlos Kuga
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The aims of this study is to evaluate the reduction in microhardness, the presence of debris and smear layer, erosion of dentin and the impact of these phenomena on the bond strength of an epoxy cement in root dentin after final irrigation with: 1. Compound of citric acid, Tween 80 and tetracycline (Biopure MTAD) 2. Compound of Cetrimide, 17% EDTA and surfactant (Smear Clear) 3. Compound of bisbiguanida acid, and surfactant poliaminocarboxilic (QMix) and 4. 17% EDTA solution, in comparison with distilled water. In dentin microhardness test, fifty palatal roots of human molars will be sectioned transversely to the long axis, obtaining a segment of 5 mm in length. After the root canal instrumentation with the instrument F3 (Protaper), the specimens will be included in acrylic resin, keeping the exposed the cervical side. All specimens are polished and divided into five experimental groups (n = 10, per group). At this time, the initial microhardness will be obtained with a microdurometer (HMV2; Shimadzu, Tokyo, Japan). The indentations will be performed in triplicate on the buccal root side, at 100 micron to the pulp-dentin interface. The load will be of 25g to 10 seconds of application. In sequence, the root canals wiil be filled with one of the solutions, divided into four experimental groups (n = 10): (QMix, Smear Clear, MTAD and 17% EDTA) and a control (distilled water). After drying, the specimens are again subjected to microhardness test, similar to that previously described, but in the lingual root side. The difference between the initial and final measurement will be a reduction in dentin microhardness caused by the solutions. The data will be submitted to ANOVA test (± = 5%). To evaluation of the presence of debris and smear layer, fifty single-rooted extracted human, with root length in 16 mm, will be instrumented to the instrument F3 (ProTaper) and in sequence subdivided into 5 groups (n = 10), similar to microhardness test. After use of the solutions in test, the root canal will be irrigated with 10 mL of distilled water and a hemisection of each root will be processed for scanning electron microscopy. Images of each specimen will be obtained in 200X and 1000X, in the apical-middle and middle-cervical segments, to evaluate the presence of debris and smear layer, respectively. With 1000X and 5000X magnification, the possible areas of dentin erosion will be evaluated and assigned scores, in accordance to the intensity of erosion of dentin. The data will be statistically analyzed using Kruskal Wallis test (± = 5%). To evaluate the interference of these substances in the adhesion of the sealer to dentin conditioned, will be used to test push-out. Fifty roots of freshly extracted human teeth of the root anatomy similar will be used. The canals will be eintrumented to F5 instrument (ProTaper) and prepared identically to previous study. After conclusion of the chemical-mechanical preparation, the specimens are divided into five groups similarly as described above. After the final irrigation canals will be filled with an epoxy-based cement. The roots are then sectioned transversely to the long axis root obtaining a specimen of each third of the root, which will be submitted to the push-out test, in a universal testing machine, with a load of 5 kN and a speed of 0.5 mm / min. The force required to displace the material will be converted in MPa. Data will be submitted to ANOVA test (± = 5%). The fracture type in the specimens will be classified as cohesive, adhesive and mixed, after obtaining and analyzing the images in stereomicrocopy. (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)

ARANDA-GARCIA, ARTURO JAVIER; KUGA, MILTON CARLOS; VITORINO, KELI REGINA; CHAVEZ-ANDRADE, GISSELLE MORAIMA; HUNGARO DUARTE, MARCO ANTONIO; BONETTI-FILHO, IDOMEO; FARIA, GISELE; REIS SO, MARCUS VINICIUS. Effect of the root canal final rinse protocols on the debris and smear layer removal and on the push-out strength of an epoxy-based sealer. MICROSCOPY RESEARCH AND TECHNIQUE, v. 76, n. 5, p. 533-537, MAY 2013. (12/03042-3)

ARANDA-GARCIA, ARTURO JAVIER; KUGA, MILTON CARLOS; CHAVEZ-ANDRADE, GISSELLE MORAIMA; KALATZIS-SOUSA, NATALIA GUIMARAES; HUNGARO DUARTE, MARCO ANTONIO; FARIA, GISELE; REIS SO, MARCUS VINICIUS; FARIA-JUNIOR, NORBERTO BATISTA. Effect of Final Irrigation Protocols on Microhardness and Erosion of Root Canal Dentin. MICROSCOPY RESEARCH AND TECHNIQUE, v. 76, n. 10, p. 1079-1083, OCT 2013. (12/03042-3)