Abstract
The aims of this study is to evaluate the presence of debris and smear layer and the impact 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. 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 divided into four experimental groups (n = 10): (QMix, Smear Clear, MTAD and 17% EDTA) and a control (distilled water). 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. 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
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