The Influence of Aging on the Fracture Load of Monolithic Crowns

Background: This in-vitro study was conducted to assess the fracture load of molar crowns fabricated with monolithic CAD/CAM materials. Methods: : The crown restorations were produced from Cerasmart, Vita Enamic, and IPS e.max CAD blocks. Dual-axis chewing simulator (50 N, 1.1 Hz, lateral movement: 1 mm, mouth opening: 2 mm, 1,200,000 cycles) and thermocycling (± 5-55 °C, 6000 cycles) were applied as an aging procedure to half of the samples. Aging was not applied to the other half of the specimens. Then, all samples were evaluated in a universal testing machine to determine the fracture loading values’. Repeated measures of Variance analysis were used for statistical analysis of the data ( p < 0.05). Results: : The aging applied Vita Enamic crowns (1978,71 ± 364,05 N) were exhibited the lowest fracture load value. No aging process applied IPS e. max CAD crowns (3098,4 ± 667,09 N) were exhibited the highest fracture load value. According to the fracture load values after the aging process, statistically significantly different was found Vita Enamic crowns from all the others. Conclusions: : Cerasmart, Vita Enamic, and IPS e.max CAD monolithic crowns used in the study were found resistant to the 5-years aging process via chewing simulator. Cerasmart, a hybrid ceramic material may be used as an alternative to IPS e.max CAD when considering the behavior against fracture load.