The Effect Of Surface Treatments and pH media On Micro-Shear Bond Strength Of Lava Ultimate Using Two Resin Cements

Abstract

This study was designed to assess the effect of two surface treatments and PH media on the micro-shear bond strength of CAD/CAM block Lava-Ultimate (resin nano-ceramic) to adhesive and self-adhesive resin cements. Lava-Ultimate blocks were used to create sixteen plates having the following dimensions:14mm x 12mm x 2mm. prepared plates were divided equally into two main groups (n=8) regarding to the surface treatment applied. Half of the plates treated with HF-acid etching and the other half treated with sandblasting, after surface treatments all plates received a silane coupling agent. Each plate received five resin micro-cylinders. Iris of polyethylene tubes having 1mm diameter and 1mm height were used, acting as a mold to create resin micro-cylinders having the same dimensions. Each maingroup (n=8)was divided into two sub-groups (n=4) according to resin cement applied, one sub-group (n=4) received adhesive resin micro-cylinders, while the other sub-group(n=4) received self-adhesive resin micro-cylinders. After that one plate from each sub-group was not-aged, while the other three plates aged in saline, milk or carbonated beverage, where one plate was immersed in one of the mentioned media. A total of eighty resin micro-cylinders were loaded under shear at a cross head speed 1mm/min till failure in a Universal Testing Machine. The micro-shear data were collected and tabulated. Three way ANOVA was used to statistically analyze the effect of surface treatment, PH media, and resin cement on the micro-shear bond strength of Lava-Ultimate and resin cements. The results revealed that regarding to surface treatment, both surface treatments used in this study showed a comparable values, where sandblasting showed a non-significant higher values. Results also concluded that PH media used in this study had a deleterious effect on micro-shear bond strength values in all the tested specimens.