title: Fatigue analysis of computer-aided design/computer-aided manufacturing resin-based composite vs. lithium disilicate glass-ceramic.
abstract: 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.
authors.affiliation: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Ankyu
authors.affiliation: Laboratory for Redox Regulation, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Harada
authors.affiliation: Liaison Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Guang
authors.initials: G
authors.lastname: Hong
authors.affiliation: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Kanno
authors.affiliation: Laboratory for Redox Regulation, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Niwano
authors.affiliation: Department of Clinical Dentistry/Faculty of Health Sciences, The Arctic University of Norway, Tromsø, Norway.|Department of Cariology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Örtengren
authors.affiliation: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Egusa
mesh_terms: D002516:Ceramics; D017076:Computer-Aided Design; D003442:Crowns; D003776:Dental Porcelain; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D006801:Humans; D008422:Materials Testing
chemical_list: C493120:lithia disilicate; D003776:Dental Porcelain
keywords: fatigue; lithium disilicate glass-ceramic; mechanical cycling; resin-based composite; thermal cycling