Aim of The Study;to evaluate the Fracture Resistance of laminate veneers constructed with two different ceramic materials (Zirconia reinforced lithium silicate glass ceramic (CeltaDUO) and Lithium disilicate glass ceramics (e.max CAD) at different load angulations (60o,125o).
Methodology:A total of 16 freshly extracted central incisors were mounted in epoxy blocks then prepared with butt joint design,then divided into 2 equal groups and subgroups Group1 e.max group (laminate veneers constructed from e.max CAD)/Group2 Celta duo group (laminate veneers constructed from Celtaduo) then each group was subdivided into 2 sub-groups according to loading angle.Group A load angle 60/Group B load angle 125o Fabricated by CEREC MC XL milling machine.The veneers were fired for a short firing cycles,then cemented with Choice 2 resin cement after surface treatment of both teeth and veneers according to manufacturer instructions.All samples were subjected to thermocycling equivalent to 1 year of clinical service.Measurements were reported after thermocycling.All samples were subjected to universal testing machine to evaluate the effect of Different load angulations (60o,125o) on fracture resistance.
Results;The highest fracture resistance mean value was recorded for e.max group with 60o loading angle followed by e.max group with 125o loading angle then CeltraDuo group with 60o loading angle while the lowest fracture resistance mean value was recorded for Celtra Duo group with 125o loading angle.
Conclusion:
1.Fracture resistance of ceramic veneers under functional Loads was higher at 60° than at 125° angle for both ceramic materials.
2.Both Celtraduo and e. max CAD laminate veneers provide clinically acceptable fracture resistance values.