The aim of this work was to measure tensile strength and microleakage of full cast crowns cemented on built-up cores using two formulations of glass-ionomer cement, Cermet and "miracle-mix", as compared to full cast crowns cemented exclusively on tooth structure. Thirty freshly extracted upper molars were selected, ten for each experimental condition. An alloy of the silver/tin system (M3) was employed to obtain the full crowns. The samples were thermocycled at 5ºC, 37ºC and 55ºC, for 60 minutes, during 7 days. For the last thermal cycle, 1% Rhodamine B aqueous solution dye was used. After that, the samples were washed and kept at room temperature for 24 hours, and taken to a universal testing machine for testing. The data were analyzed by parametric and non parametric statistical methods and the following conclusions were drawn: 1 - there was a statistically significant difference in removal resistance of cemented full crowns under the various conditions; 2 - the crowns cemented on the "miracle-mix" and Cermet reconstructed teeth showed statistically significant lower removal resistances than controls (teeth which had not been reconstructed); 3 - no statistically significant difference was found comparing teeth reconstructed either with "miracle-mix" or Cermet; 4 - no statistically significant differences were found between microleakage patterns in teeth rebuilt with the "miracle-mix" and with Cermet; 5 - statistically significant differences were found between microleakage patterns in teeth rebuilt with "miracle-mix" and Cermet cores as compared to the non reconstructed group (control)
Crowns; Glass-ionomer cements; Cermet cements
