Aim: to assess the fracture resistance of maxillary molars restored using lithium disilicate glass-ceramic (LDG) table-top restorations fabricated with two different production protocols.
Methods: sixteen maxillary molars were randomly assigned to two groups (n = 8). The teeth received a preparation for a full-coverage table-top restoration with a 90° rounded shoulder margin. Restorations were fabricated using monolithic LDG blocks milled via Cerec 3 CAD/CAM System in group 1 (G1) and heat-pressed LDG in group 2 (G2). All table-tops were luted with Variolink II cement. The specimens were loaded to fracture after thermomechanical aging (1 250 000 cycles). A qualitative analysis on the type of fracture was conducted. Collected data were statistically analyzed with non-parametric test (Mann Whitney U-test).
Results: the mean load to fracture was 2395.01 ± 150.96 N in G1 and 1796.58 ± 307.27 N in G2; the difference was statistically significant (p < 0.05). The majority of the specimens showed restorable fractures (6 specimens in G1 and 6 specimens in G2).
Conclusion: the milled CAD/CAM LDG table-top restorations withstood higher load before fracturing than the restorations made with the heat-pressed LDG production protocol.
