Retentive strength evaluation of resin cements in two-piece zirconia abutments

Abstract

Objective : To evaluate, in vitro, the retentive strength between the two-piece zircônia abutments, comparing different types of resin cements.Methods: Thirty zirconia parts manufactured by CAD-CAM technology were divided into three groups, according to the resin cement used for their cementation on the metallic titanium bases: dual-curing self-adhesive, dual-curing conventional and chemically activated. The specimens were stored in distilled water (24 hours, 37°C), followed by thermocycling and submitted to 30 s in baths of 5°C and 55°C, 2 s displacement time, with 6,000 cycles. The mechanical cycling tests werecarried out with specimens submerse in distilled water (37°C), with load of 100N, 2 H z frequency and 200,000 cycles. After thermomechanical tests, the specimens were submitted to a tensile test using a universal testing device until the complete separation of, which were analyzed in stereomicroscope, to determine the cementation failure pattern.Results : The adhesive-type cementation failure occurred in all specimens. The retentive strength values did not differ statistically between the groups.Conclusion : All three tested resin cements provided enough retentive to the two-piece zirconia abutments.