Study of testing types used on the evaluation of dentin-composite bond / Estudo de metodologias utilizadas na avaliação da resistencia mecanica da união composito-dentina

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The aim of this study was to evaluate the dentin-restorative composite strength of 2 adhesive systems Clearfil SE Bond (CSEB) and Single Bond (SB) using 4 different tests: Shear , Tensile, Micro-shear and Micro-tensile tests. 52 bovine incisors were used in this study which were cut and embedded in PVC tubes (20mm internal diameter, 40mm height) with polyester resin. Buccal surfaces were flattened with sandpaper grit number 180 and 400 under water refrigeration. For the shear bond (SH) strength tests, a circular area of 5mm in diameter was delimited and adhesive systems were applied according to the manufacturers` instructions. A composite cylinder (Z250) of 4mm diameter and 5mm height were built in the area. The loading occurred on Instron testing machine at crosshead speed of 0.5mm/min. using a metallic tape which evolved the cylinder. The tensile test (TEN) were run used samples made with use of a conical shape - metallic mould with 6mm and 4mm in diameter on the edges. The smaller edge was positioned on the surface and a composite put in its internal portion. The loading were carried out at crosshead speed of 0.5mm using a metallic device which evolved the sample. The microshear tests (µ-SH) were carried out using composite samples of 0.7mm in internal diameter in 0,4mm height, built by the use of Tygon tubes (TGY-030). Loading were carried out at crosshead speed of 0.5mm using an orthodontic wire loop (0.3mm). The micro-tensile tests (µ-TEN) were run using sticks with 1mm² of cross seccional area. These sticks were adhered to an testing device using cyanoacrilate glue (Super Bonder Gel) and tested using an Instron testing machine at crosshead speed of 0.5mm/min. Data showed that CSEB bonding system had higher values with statistical significance for all tests compared to SB bonding system (p>0.05) (CSEB/SH=6.35MPa; SB/SH=3.02MPa; CSEB/TEN=12.43MPa; SB/TEN=7.11MPa; CSEB/µ-SH=36.52MPa; SB/µ-SH=26.39MPa; CSEB/µ-TEN=30.10MPa; SB/µ-TEN=21.08MPa). The CSEB showed cohesive and mixed failure for all tests. SB bonding system showed adhesive failure for the most tests

ASSUNTO(S)

dentina materiais dentarios dental materials dentin

ACESSO AO ARTIGO

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