Resistência à remoção por tração de coroas totais metálicas cimentadas em dentes com e sem reconstrução coronária

The purpose of this study was to evaluate the tensile strength of metal crowns cemented with Ketac-Cem (ESPE) glass ionomer cement, on teeth properly prepared with and without previous treatment of 40% polyacrylic acid, as well as on built-up teeth reconstructed with Vitremer (3M) ionomer cement. For comparison purposes, zinc phosphate cement (SS White) was also employed. Fifty upper pre-molar human teeth were selected, embedded in epoxy resin, and divided into 5 groups of 10 elements each. After cementing, the specimens were submitted to thermocycling at 5°C, 37°C and 55°C, and later subjected to tensile tests in a Universal Kratos testing machine. The results obtained were submitted to ANOVA, showing statistically significant differences (5%) between the distinct conditions studied. Regarding the teeth without reconstruction, we verified improved results of Ketac-Cem when using polyacrylic acid. The teeth reconstructed with Vitremer did not show significant statistical difference between the two cementing agents. The reconstruction of teeth buildup surfaces did not hinder the retentiveness of the metal crowns.