Do the Microshear Test Variables Affect the Bond Strength Values?

Abstract EN

Little is known about the effect of specimen preparation and testing protocols on the micro-shear bond strength (μSBS) results.

To evaluate whether variations in polyethylene rod use affect (μSBS)).

Human dentin disks were randomly distributed into six groups (n=5): polyethylene tube (3 levels) and adhesive system (2 levels).

In Group 1, polyethylene tubes filled with polymerized composite) were placed on adhesive covered surfaces.

Tubes were removed 24 h after water storage, leaving the rods only.

In Group 2, the same procedure was performed; however, tubes were kept in place during testing.

In Group 3, composite rods without tubes were placed on adhesive covered dentin.

In all groups, adhesives were photoactivated after positioning filled tubes/rods on adhesive covered surfaces.

Specimens were tested under shear mode and the data subjected to a two-way ANOVA and Tukey’s tests.

Groups 1 and 2 resulted in statistically similar mean μSBS (P>0.05); however, a greater number of pretest failures were observed for Group 1.

Higher μSBS values were detected for Group 3, irrespective of adhesive system used (P<0.05).

Removing the polyethylene tube before composite rod is placed on dentin affects μSBS values.