Introduction: The resistance to fracture of all-ceramic prostheses may be positively or negatively affected by the distribution of compressive and tensile residual stresses within the relatively weak veneering ceramic. Objective: To determine the effect of slow-cooling and fast-cooling on residual stresses as a function of distance from the surface of monolithic and bilayered dental veneer. Methods: Monolithic veneer (M) and bilayer (B) veneer/ceramic-core bars (e.max Ceram and e.max Press, Ivoclar Vivadent, Schaan, Liechtenstein) were fabricated according to the manufacturer's recommendations.  After heat treatment, the specimens were either fast-cooled (FC) or slow-cooled (SC). The twenty specimens were 40mm x 2mm x 4mm and polished through 1μm abrasive. Vicker's microindentations (n=1000) were produced at distances (200, 300, 400, 600, 800μm) from the veneer surface using a 9.8N load. Indentation-crack length images were captured and measured using a calibrated image capture system (Buehler, Lake Bluff, IL).  Residual stress was calculated (Kese and Rowcliffe, 2000) for each of the cooling treatments (FC or SC). Statistical analysis was performed to determine the influence of main effects and interactions on residual stress.  Results: Results revealed that there were statistically significant differences in stresses associated with SC and FC treatments; bilayer effect (M>B); and test location (p<0.0001 for each). The negative values indicate compressive stresses.

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