Comparative fracture behavior of monolithic and veneered zirconia posterior fixed dental prostheses.

The purpose of this study was to evaluate and to compare the fracture load and the fracture pattern of monolithic and veneered zirconia posterior fixed dental prostheses (FDPs). Twenty standardized steel dies were prepared to receive posterior 3-unit FDPs. Specimens were randomly divided into 2 groups (n=10): (1) Lava Zirconia, and (2) Lava Plus. All FDPs were cemented using glass ionomer cement and subjected to thermal and mechanical cycling at 5-55ºC with a 30-s dwell time for 120,000 masticatory cycles. All specimens were subjected to a three-point bending test until fracture. Data were statistically analyzed using Student's t test, paired t-test and Weibull statistics (α=0.05). No differences were observed in fracture load between the groups. Veneering ceramic fractured before than framework in veneered zirconia group. The fracture pattern was different. The tested groups demonstrated clinically acceptable fracture load values. Monolithic zirconia solves the chipping problem.