Figure 3.

Mouth-motion step stress fatigued veneered Y-TZP crowns exhibiting typical veneer chipping failure mode. In views A-C, an approximately uniform 1.0-mm core was veneered with 0.5-1.0 mm porcelain, while in views D-F, a 0.5-mm core had a 1.0- to 1.5-mm veneer applied. The anatomic core support resulted in smaller chips which developed at higher loads than for the less supportive thinner core. Note that the veneer-core interface is rarely exposed. These laboratory test results parallel clinical reports.