Reinforcing experimental resin-composites with synthesized zirconia and alumina nanofibers: evaluation of cuspal flexure, flexural strength, flexural modulus and fracture toughness

Abstract

Aim: This study evaluated cuspal flexure, flexural strength, flexural modulus and fracture toughness of experimental resin-composites reinforced with zirconia and alumina nanofibers. Zirconia and alumina nanofibers were synthesized by wet electrospinning technique. Characterization of these nanofibers was carried out by scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy that confirmed pure forms of zirconia nanofibers (50–100 nm in diameter) and alumina nanofibers (70–100 nm in diameter). Materials and methods: The study was divided into seven groups (n = 10/group) according to the type and percentage of added nanofibers: control group, three groups reinforced with 2, 4 and 6 wt% zirconia nanofibers and more three groups reinforced with 2, 4 and 6 wt% alumina nanofibers. Results: A one-way analysis of variance revealed significant differences between the studied groups (P = 0.000) for all investigated properties. Mean cuspal flexure ranged between 0.13 and 0.36% with markedly lower values for groups with higher percentages of nanofibers. For flexural strength, data ranged between 98 and 168 MPa, for flexural modulus between 7.6 and 17.04 GPa, and for fracture toughness between 1.16 and 3.51 MPa m1/2 with greater values recorded for nanofibers-reinforced groups. Conclusion: Zirconia nanofibers were superior to alumina nanofibers in reducing cuspal flexure and improving the studied mechanical properties.