2024-03-28T12:46:54Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/154252012-04-24T22:00:00Zcom_10261_78com_10261_3col_10261_331
00925njm 22002777a 4500
dc
Baudín de la Lastra, Carmen
author
Osorio, Raquel
author
Toledano, Manuel
author
Aza Pendas, Salvador de
author
2008
The aim of this work was to investigate those
mechanical parameters able to describe the fracture behavior
of dental composite resins. A commercially available
fine-particle micro-hybrid resin composite was used. Classical
parameters as Young’s modulus, strength distribution,
and critical stress intensity factor were considered. Strength
values were determined using the diametrical compression
of discs test and for the critical stress intensity factor both
unstable and controlled fracture tests were used. Controlled
fracture tests allowed determining the work of fracture.
Microstructure was studied by optical and field emission
scanning electron microscopy. The obtained properties have
been Young’s modulus, 17.7 6 0.6 GPa; Weibull modulus,
m 5 14 (upper and lower limits for 90% confidence: 17 and
10); characteristic strength 51 MPa (upper and lower limits
for 90% confidence: 53 and 49 MPa); critical stress intensity
factor in mode I, KIC 5 1.3 6 0.1 and work of fracture, gwof
5 8–9 J/m2. Pores and bubbles formed during the packing
of the composite were identified as critical defects in the
tested specimens. Crack deflection and branching have been
identified as toughening mechanisms. Classical mechanical
parameters (Young’s modulus, hardness. . .) are not able to
efficiently predict the major clinical failure mode of composite
resins by fatigue. Work of fracture analysis, which is
dependant on microstructural parameters such as particle
size and shape, have to be included when testing mechanical
properties of dental composite resins in future research
studies.
Journal of Biomedical Materials Research Part A
http://hdl.handle.net/10261/15425
10.1002/jbm.a.32016
Composite resin
work of fracture
strength
Young’s modulus
Work of fracture of a composite resin: Fracture-toughening mechanisms