Method: Twelve extracted premolars received a tooth preparation for laminate veneers with the buccal cusp completed covered. Four groups were made: Group A1 (n = 3) – Laminate veneers restored with the Leucite reinforced (IPS d.sign) submitted a FS and SLF; Group A2 (n = 3) – Restored with lithium disilicate ceramics (IPS e.max Press) submitted to FL and SLF, Group B1 (n = 3) – Restored with the Leucite reinforced (IPS d.sign) FL and Group B2 (n = 3) – Restored with lithium disilicate ceramics (IPS e.max Press) submitted to FS. All laminate veneers were restored with a 0. 5 mm thick (IPS d.sign and IPS e.max) and bonded with resin cement (Variolink II, Ivoclar Vivadent). A cyclic load of 1,200.000 cycles and and isometric load (50 N) at 2 Hertz were used, and a compressive test (SLF) of 0.5/mm were performed using a universal machine. The number of cycles or the loading to failure at initial failure (first cracks) was recorded. The results were compared using Tukey test (p < 0.1).
Result: All samples survive to FL, and fracture after SLF. There were no statistical differences between groups. However the groups A2 (350, 76 N medium fracture value) and B2 (417, 61 N medium fracture value) showed an average fracture load greater than groups A1 (325,33 N medium fracture value) and B1 (253,44 N medium fracture value).
Conclusion: No statistical differences were found between veneering materials and type of loading stress.