Effect of 4-META adhesive on the bond strength of different metal framework designs and acrylic resins.

The effect of relining the 4-META adhesive resin onto metal alloy of a partial denture framework was tested. Seventy-two metal frameworks with three different retentive patterns were designed. Half of the specimens were treated with 4-META, the other group was left untreated. Thirty-six specimens were first divided into three groups in which 12 samples had different designs of retention, i.e. mesh, ring-shaped and flat plane. Then, each different retentive design was divided into two groups and in one group Lucitone 199 and the other QC acrylic resin were processed. Finally they were subjected to shear test. While samples with adhesive exhibited greater bond strength than the others, samples without adhesive may be ranked in the order mesh, ring-shaped and flat planes with regard to shear bond strength. In samples with adhesive, the flat plane ones displayed better results. Statistically significant differences were observed in the relationships between the groups.