Evaluation in vitro of the influence of auxiliary chemicals in microleakage, bond strength and intrarradicular adhesive durability

Abstract

This study aims to evaluate in vitro the influence of chemical substances auxiliary (sodium hypochlorite 5.25% Chlorhexidine Gluconate 2%, EDTA 17%) in the adhesive properties of resin materials associated with the root dentin. For a wider scope of this research work will be divided into two parts:Part 1Evaluation of the effect of different chemicals in the microleakage and bond strength of resin root canal sealer AH Plus. To evaluate the microleakage will be used palatal roots of maxillary molars divided into 18 groups (n = 12) who receive different chemical treatments, will be obtured and its microleakage evaluated by the fluids infiltration method. The evaluation of bond strength of root canal sealer to dentin will be realized in the roots of teeth that animals receive the same protocols of chemicals used to evaluate the microleakage. These roots are adapted arrays of silicone is inserted where the AH Plus cement, with or without an adhesive system. After removal of the matrix, the specimens are tested for bond strength to dentin by means of mechanical testing machine EMIC DL 2000. Subsequently, the mode of fracture will be examined by scanning electron microscopy, and classified into: adhesive (cement dentin interface) or cohesive (in cement, hybrid layer, or mixed). The results will be analyzed statistically.Part 2This study aims to evaluate in vitro the influence of two chemical substances auxiliary to the endodontic treatment (5.25% sodium hypochlorite, 2% chlorhexidine gluconate) and the use of ethanol before the use of different adhesive systems (Clearfil SE Bond or Scotchbond Multi Purpose) on (1) bond strength and (2) adhesion longevity of fiber glass post model with composite resin to intrarradicular dentin. Besides that, it aims to check the real importance of the collagen fibers in this adhesion. The samples will be subjected to mechanical test extrusion by push out, after immersion in water in intervals of 1 day and 1 year. To control the hydrolysis collagen, part of the sample, corresponding to the period of 1 year, will be immersed in mineral oil. Subsequently, the mode of fracture will be examined by scanning electron microscopy and classified into: adhesive (resin dentin interface); or cohesive (in dentin, hybrid layer, resin or mixed). The results will be analyzed statistically. (AU)