Abstract
This study was conducted to examine the influence on bond strength of the white layer produced after ceramic-making and of crystal mica in the cements when Dicor castable ceramics are cemented with enamels using Dicor light activated cements.
Shear and tensile tests of the bond strength were conducted together with observation of the failed surface by means of SEM (scanning electron microscope).
The following results were obtained:
1. Bond strength
1) The bond strength was 229-317kgf/cm2 in the shear test, and 108-125kgf/cm2 in the tensile test.
2) Cementing without a white layer displayed more bond strength in both tests than that with a white layer.
3) Cementing with cements containing no crystal mica displayed more bond strength in both tents than that with crystal mica.
2. Observation by SEM
1) When cementing with a white layer, destruction of needle-like particles, which developed in the white layer, was found.
2) When cementing with cements containing crystal mica, destruction phases were found on the cement layer.
These results suggest that Dicor cementation is an effective way to eliminate the white layer completely as well as cementing with cements containing no crystal mica.
