Fracture strength and fatigue resistance of dental resin-based composites.
OBJECTIVE
The aim of this study was to evaluate in vitro the influence of fiber-reinforcement on the fracture strength and fatigue resistance of resin-based composites.


METHODS
One hundred rectangular bar-shaped specimens (2 mm x 2 mm x 25 mm) made of resin-based composite were prepared in a stainless steel split-mould: (i) thirty specimens of particulate filler composite (PFC) (Filtek Z100, 3M ESPE, St Paul, MN, USA), (ii) thirty specimens of fiber-reinforced composite (FRC) (Everstick C&B, Sticktech Ltd., Turku, Finland) and (iii) forty specimens of PFC and FRC combined in two longitudinal layers of equal thickness. Each specimen was trimmed into a cylindrical hourglass shape. The fracture strength (cantilever beam test, n=10) and the fatigue resistance (rotating cantilever beam test; staircase method: 10(4) cycles, 1.2 Hz, n=20) were determined. Fracture strength, fatigue resistance and work-of-fracture were calculated. The fracture surfaces of failed specimens were analyzed with SEM. Data was analyzed by logistic regression, one-way ANOVA followed by Tukey's post hoc test and, a Student's t-test.


RESULTS
ANOVA revealed that fiber-reinforcement had significant effect (P<0.001) on fracture strength, fatigue resistance, and work-of-fracture. Student's t-test showed significant differences (P<0.001) in fatigue resistance compared to fracture strength.


CONCLUSIONS
Within the limitations of this study, the following conclusions can be drawn (i) the fatigue resistance of resin-based composites is lower than their fracture strength and (ii) FRC are more fatigue resistant than PFC or combinations of FRC and PFC.
Keulemans
Filip
F
Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Louwesweg 1, 1066 EA Amsterdam, The Netherlands. f.keulemans@acta.nl
Palav
Prem
P
Aboushelib
Moustafa M N
MM
van Dalen
Andy
A
Kleverlaan
Cornelis J
CJ
Feilzer
Albert J
AJ
D000465:Algorithms; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D005898:Glass / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D018583:Pliability; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012399:Rotation; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry
D003188:Composite Resins; D003764:Dental Materials; D011109:Polymethacrylic Acids; D012821:Silanes; C083568:Z100 composite resin; C496140:everStick; C009753:fiberglass; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D019904:Polymethyl Methacrylate; D015040:Zirconium; C028541:zirconium oxide