Evaluation of Fracture Resistance and Color Stability of Crowns Obtained by Layering Composite Over Zirconia and Polyetheretherketone Copings Before and After Thermocycling to Simulate Oral Environment: An Study.

Background: Most common material used for the fabrication of an implant restoration is full-ceramic crown or an all-ceramic crown. Frequent chipping of the ceramic under occlusal load has posed a great problem to the clinician and the patient. Composites have been layered over zirconia successfully in the recent past to overcome this problem.