Resistência de união entre liga de níquel-cromo e cimentos resinosos

The purpose of the investigation was to test tensile strength between Ni-Cr alloy and adhesive cements. Variables were: three cements (Comspan, Panavia Ex and All-Bond CB four surface treatments (smooth, sandblasted, electrolytic etching and silicoater); two types of storage (3 and 30 days in NaCl 0.9% solution at 37° C, performing in the latter 600 thermocycles at 5 and 55° C). Specimens were discs obtained through conventional casting procedures and cemented together two by two. Opposite sides of cementing discs were provided with a loop for fixing to the testing equipment. Conclusions were that: smooth surfaces presented very low retentivity and those with silicoater a very high one; Panavia Ex with sandblasting also led to very high retention; highest retention was obtained with the combination silicoater/All-Bond C&B.