Fatigue resistance of composite resins and glass-ceramics on dentin and enamel

• Published in: The Journal of prosthetic dentistry 2022-04, Vol.127 (4), p.593-598
• Main Authors: de Kok, Paul, Kanters, Gustave F., Kleverlaan, Cornelis J.
• Format: Article
• Language: English
• ISSN: 0022-3913; 1097-6841
• DOI: 10.1016/j.prosdent.2020.11.002

Composite resins and glass-ceramics are both used to restore worn teeth. Which restoration material is more durable is unclear. The purpose of this in vitro study was to evaluate the load to failure of thin composite resins and glass-ceramic restorations on enamel and dentin under increasing repetitive loads. Glass-ceramic blocks (IPS e.max CAD; Ivoclar AG) were shaped into cylinders (Ø4.0×1.0 mm), crystallized, and adhesively luted to bovine dentin and enamel substrates that were embedded in polymethyl methacrylate (n=20). Identical direct composite resin restorations (Clearfil AP-X; Kuraray Noritake Dental Inc) were made and directly applied on the same substrates (n=20). All specimens were tested in a pneumatic device with a stainless steel ball that provided a stepwise increase of the load (N) starting at 250 N and increasing by 50 N after every 10 000 cycles to a maximum of 1150 N. Failures were detected by a displacement sensor and defined by chipping of restorative material or catastrophic failure. On dentin, composite resin showed a significantly higher fatigue resistance than glass-ceramic. On enamel, no significant difference was found between the 2 materials. When bonded to dentin, thin direct composite resin restorations were more durable than glass-ceramics. When bonded to enamel, no difference was found.