Fatigue analysis of computer-aided design/computer-aided manufacturing resin-based composite vs. lithium disilicate glass-ceramic.

Resin-based composite molar crowns made by computer-aided design/computer-aided manufacturing ( CAD/ CAM) systems have been proposed as an inexpensive alternative to metal-ceramic or all-ceramic crowns. However, there is a lack of scientific information regarding fatigue resistance. This study aimed to analyze the fatigue behavior of CAD/ CAM resin-based composite compared with lithium disilicate glass-ceramic. One-hundred and sixty bar-shaped specimens were fabricated using resin-based composite blocks [Lava Ultimate ( LU); 3M/ ESPE] and lithium disilicate glass-ceramic [ IPS e.max press ( EMP); Ivoclar/Vivadent]. The specimens were divided into four groups: no treatment ( NT); thermal cycling ( TC); mechanical cycling ( MC); and thermal cycling followed by mechanical cycling ( TCMC). Thermal cycling was performed by alternate immersion in water baths of 5°C and 55°C for 5 × 10 4 cycles. Mechanical cycling was performed in a three-point bending test, with a maximum load of 40 N, for 1.2 × 10 6 cycles. In addition, LU and EMP molar crowns were fabricated and subjected to fatigue treatments followed by load-to-failure testing. The flexural strength of LU was not severely reduced by the fatigue treatments. The fatigue treatments did not significantly affect the fracture resistance of LU molar crowns. The results demonstrate the potential of clinical application of CAD/ CAM-generated resin-based composite molar crowns in terms of fatigue resistance. [ABSTRACT FROM AUTHOR]

Copyright of European Journal of Oral Sciences is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)