Survival rate and fracture strength of maxillary incisors, restored with different kinds of full veneers

Abstract

This in vitro study evaluated the survival rate and fracture strength of different kinds of ceramic full veneers, fabricated with a new experimental press ceramic (EPC VP2117/TC2, Ivoclar-Vivadent AG, Schaan, Liechtenstein). Eighty, caries-free human maxillary central incisors were used as abutments and were randomly divided into one control group and four test-groups of 16 samples each. In group A, unprepared teeth served as control. In the test groups, four different types of full veneer preparations were performed. In test groups B/C, the preparation was maintained in enamel and the contact point was on the tooth/on the veneer, respectively. In test groups D/E, the preparation was extended into dentin and the contact point was on the tooth/on the veneer, respectively. All veneers were adhesively luted using Variolink II (Ivoclar-Vivadent AG). Then, the samples were exposed to the artificial mouth for 1.2 million chewing cycles (49 N). After exposure in the artificial mouth, a survival rate of the abutment teeth of 81-100% was reported among the different groups, but was not significantly different between the groups. However, no failures of the ceramic materials could be recognized. The median fracture strength of group A was 713.3 N, of group B 647.1 N, of group C 594.8 N, of group D 483.8 N and of group E 502.6 N. Among the different groups no significant difference was found. All mean values obtained were within the limits of clinical acceptance, indicating further clinical investigations on full veneers made out of the EPC.