Abstract

The aim of this research work is to study the reinforcement effect of nylon 66 nanofibrous mats on the mechanical properties of the three different dental composites, termed as Nanohybrid, Microhybrid and, Microfill. Nylon 66 nanofibrous mats were prepared by using the electrospinning technique at different spinning dope concentrations (17, 20 and 23 wt.) and characterized by a scanning electron microscopy and a mechanical tester. The obtained mats were added to the dental composites in a laminate form with the weight fraction of 0, 0.5, 1.5, 3 and 6. The flexural strength (F-s), elastic modulus (E-y), and work of fracture (WOF) of the dental composites were evaluated using three-point bending test and the Vickers hardness of the composites was studied using microhardness test. Obtained results showed that by increasing the spinning solution concentration, the diameter of the resultant nanofibers increased which further increased the tensile strength of the nanofibrous mats. The results of the three-point bending test indicated that F-s, E-y, WOF of the nanofiber reinforced composites were all significantly increased by the addition of nylon 66 nanofibers; as an illustration, the addition of 6 nanofibrous mats (23 wt) improved F(s )of the Microhybrid composite by 68.08, E-y of the Nanohybrid composite by 509, and WOF of the Microfill composite by 106.08, as compared to those of the pure dental composite. Furthermore, the incorporation of the nanofibers within the resin matrix increased the microhardness value of the reinforced resin, as compared to the unreinforced resin, for all three different dental composites.