Fracture Strength of Ceramic Posterior Occlusal Veneers for Functional Rehabilitation of an Abrasive Dentition

Purpose: To evaluate the load at fracture and influence of artificial aging of posterior teeth occlusal veneers (table tops) made of two different ceramics. Materials and Methods: A total of 80 table tops were produced from feldspathic ceramic (VM) and zirconia-reinforced lithium silicate ceramic (CD) using computer-aided design/computer-assisted manufacturing (CAD/CAM). Half of the specimens from each ceramic were aged prior to the load test. Results: Mean +/- standard deviation (SD) load at fracture was significantly higher for CD (1,571.1 N +/- 297.0 N) than for VM (573.6 N +/- 86.4 N) (P < .001). After aging, load at fracture increased significantly to 1,819.0 N (+/- 310.6 N) for CD and to 745.2 N (+/- 168.3 N) for VM. Conclusion: The use of zirconia-reinforced lithium silicate ceramic for molar nonprep table tops should be uncomplicated according to the high load-at-fracture values. Mechanical stability of either ceramic is not compromised by aging.