Influence of material type, thickness and storage on fracture resistance of CAD/CAM occlusal veneers

• Published in: Journal of the mechanical behavior of biomedical materials 2021-07, Vol.119, p.104485-104485, Article 104485
• Main Authors: Albelasy, Eman, Hamama, Hamdi H., Tsoi, James K.H., Mahmoud, Salah H.
• Format: Article
• Language: English
• Subjects: Aging; CAD/CAM composite; Fracture resistance; Lithium disilicate glass-ceramic; Non-retentive occlusal veneers; Polymer-infiltrated ceramic
• ISSN: 1751-6161; 1878-0180
• DOI: 10.1016/j.jmbbm.2021.104485

The present study aimed to evaluate the effect of restoration thickness, CAD/CAM material, and 6 months of artificial saliva storage on the fracture resistance of occlusal veneers. A total of 84 intact maxillary molars were sectioned 4.0 mm occlusal to the cementoenamel junction to expose the dentine. The teeth were assigned into 3 main groups according to the type of restorative material (e.max CAD, Vita Enamic, and Lava Ultimate). In each group, the teeth were allocated into 2 subgroups (n = 14) according to restoration thickness (1.0 and 1.5 mm). The veneers were adhesively bonded using dual-cure self-adhesive luting agent. A total of 42 specimens comprising half the tested subgroups were stored in distilled water for 24-h before the test. The remaining half was stored in artificial saliva at 37 ± 1 °C in an incubator for 6 months. All specimens (n = 84) were subjected to 5000 thermal cycles between 5 and 55 °C ± 2 before the fracture resistance test. The maximum force at fracture was recorded in Newton. Failure mode was analyzed using a stereomicroscope. The results were analyzed using a parametric Three-way ANOVA test. The results of the Three-way ANOVA test revealed that material type and restoration thickness significantly affected fracture resistance values (p