EFFECT OF BERYLLIUM ON THE CASTABILITY AND RESISTANCE OF CERAMOMETAL BONDS IN NICKEL-CHROMIUM ALLOYS

Statement of problem. Castability and ceramometal bond resistance play an important role in accepting nickel-chromium alloys as a substitute for gold alloys in dentistry. Purpose. This study was developed to ve rify the effect of beryllium on these factors in several compositions of nickel-based alloys by submitting them to castability and ceramomet al bonding resistance tests. Material and methods. Three experimental compositions of Ni-Cr allays with different amounts of beryllium were used. One beryllium-free alloy was used as the control. Results. Analy sis of variance and Tukey's test showed significant differences (alpha =.001) for the castability test results and significant differences (a lpha=.05) for ceramometal bond resistance between alloys. Conclusions. Although the amounts of chromium, manganese, and niobium were maintai ned, the variations in the amounts of beryllium allowed the estimation that Be-containing alloys presented better castability than Be-free a lloys. The 0.9% Be-containing alloy demonstrated higher resistance of the ceramometal bond than the Be-free alloy.