Table of Contents
Journal of Composites
Volume 2016, Article ID 3823952, 13 pages
Research Article

Mechanical Properties Comparing Composite Fiber Length to Amalgam

1Departments of Biomedical Engineering, Biomaterials and Restorative Sciences, University of Alabama at Birmingham, SDB 539, 1919 7th Avenue South, Birmingham, AL 35294, USA
2Department of Restorative Sciences, University of Alabama at Birmingham, SDB 539, 1919 7th Avenue South, Birmingham, AL 35294, USA

Received 30 August 2015; Revised 17 January 2016; Accepted 19 January 2016

Academic Editor: Francesco Aymerich

Copyright © 2016 Richard C. Petersen and Perng-Ru Liu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Photocure fiber-reinforced composites (FRCs) with varying chopped quartz-fiber lengths were incorporated into a dental photocure zirconia-silicate particulate-filled composite (PFC) for mechanical test comparisons with a popular commercial spherical-particle amalgam. FRC lengths included 0.5-mm, 1.0 mm, 2.0 mm, and 3.0 mm all at a constant 28.2 volume percent. Four-point fully articulated fixtures were used according to American Standards Test Methods with sample dimensions of  mm3 across a 40 mm span to provide sufficient Euler flexural bending and prevent top-load compressive shear error. Mechanical properties for flexural strength, modulus, yield strength, resilience, work of fracture, critical strain energy release, critical stress intensity factor, and strain were obtained for comparison. Fiber length subsequently correlated with increasing all mechanical properties, . Although the modulus was significantly statistically higher for amalgam than all composites, all FRCs and even the PFC had higher values than amalgam for all other mechanical properties. Because amalgams provide increased longevity during clinical use compared to the standard PFCs, modulus would appear to be a mechanical property that might sufficiently reduce margin interlaminar shear stress and strain-related microcracking that could reduce failure rates. Also, since FRCs were tested with all mechanical properties that statistically significantly increased over the PFC, new avenues for future development could be provided toward surpassing amalgam in clinical longevity.