Measuring the Shear Bound Strength on Acrylic Resin Veneer to Metal Surface of Nickel (A Comparative Study)

Abstract

The bound strength of metal resin interface of prosthesis is a key factor in determining the service ability of that prosthesis. The main objective of this study was to determine the effect of different surface treatment on the shear bond strength of Ni-Cr alloy (CB-Blando 72 alloy) and heat cured acrylic veneer resin (Vertex). Thirty disc shaped samples from base plate wax were prepared, the diameter of disc was (8 mm x 4.5 mm). After casting the metal, the samples were cleaned, finished and polished by silicon carbide abrasive paper with grit size (600 μm) and then the profilometer was u sed to determine the surface roughness of samples. Then the sa mples were divided in to three groups, each group contain (10) sa mples. The first group rece ived no treatment and serve as control .The Second group received micro mechanical treatment using 250 μm Al2o3 .The third group recived micro mechanical treatment using 400 μm Al2o3. The acrylic was prepared as a round shape (8 μm) in diameter and (2 μm) in thickness, which was placed on the metal surface treatment, the acrylic was fabricated in the same conventional way for construction veneer resin. Then all samples was tested the shear bond strength by using Instron universal testing machine .The result from this study showed that, the first group was give low shear bond strength while the second group showed that the air abrasion with 250 μm Al2o3 give the highest shear bond values when compared with the third group which air abrasive with 400 μm Al2o3.