Subcritical crack growth and in vitro lifetime prediction of resin composites with different filler distributions

Ornaghi BP, Meier MM, Rosa V, Cesar PF, Lohbauer U, Braga RR (2012)

Publication Type: Journal article

Publication year: 2012

Journal

Dental Materials Elsevier

Book Volume: 28

Pages Range: 985-995

Journal Issue: 9

DOI: 10.1016/j.dental.2012.05.001

Abstract

Objectives: Verify the influence of different filler distributions on the subcritical crack growth (SCG) susceptibility, Weibull parameters (m and σ 0) and longevity estimated by the strength-probability-time (SPT) diagram of experimental resin composites. Methods: Four composites were prepared, each one containing 59 vol% of glass powder with different filler sizes (d 50 = 0.5; 0.9; 1.2 and 1.9 μm) and distributions. Granulometric analyses of glass powders were done by a laser diffraction particle size analyzer (Sald-7001, Shimadzu, USA). SCG parameters (n and σ f0) were determined by dynamic fatigue (10 -2 to 10 2 MPa/s) using a biaxial flexural device (12 × 1.2 mm; n = 10). Twenty extra specimens of each composite were tested at 10 0 MPa/s to determine m and σ 0. Specimens were stored in water at 37 °C for 24 h. Fracture surfaces were analyzed under SEM. Results: In general, the composites with broader filler distribution (C0.5 and C1.9) presented better results in terms of SCG susceptibility and longevity. C0.5 and C1.9 presented higher n values (respectively, 31.2 ± 6.2 a and 34.7 ± 7.4 a). C1.2 (166.42 ± 0.01 a) showed the highest and C0.5 (158.40 ± 0.02 d) the lowest σ f0 value (in MPa). Weibull parameters did not vary significantly (m: 6.6 to 10.6 and σ 0:170.6 to 176.4 MPa). Predicted reductions in failure stress (P f = 5%) for a lifetime of 10 years were approximately 45% for C0.5 and C1.9 and 65% for C0.9 and C1.2. Crack propagation occurred through the polymeric matrix around the fillers and all the fracture surfaces showed brittle fracture features. Significance: Composites with broader granulometric distribution showed higher resistance to SCG and, consequently, higher longevity in vitro. © 2012 Academy of Dental Materials.

Authors with CRIS profile

Ulrich Lohbauer Medizinische Fakultät

Involved external institutions

University of Passo Fundo (UPF) BR Brazil (BR) University of São Paulo / Universidade de São Paulo (USP) BR Brazil (BR) Universidade Positivo (UP) BR Brazil (BR)

How to cite

APA:

Ornaghi, B.P., Meier, M.M., Rosa, V., Cesar, P.F., Lohbauer, U., & Braga, R.R. (2012). Subcritical crack growth and in vitro lifetime prediction of resin composites with different filler distributions. Dental Materials, 28(9), 985-995. https://doi.org/10.1016/j.dental.2012.05.001

MLA:

Ornaghi, Barbara P., et al. "Subcritical crack growth and in vitro lifetime prediction of resin composites with different filler distributions." Dental Materials 28.9 (2012): 985-995.

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