Effects of using fibres on fracture resistance of composite resins

Objective: to investigate the effects of polyethylene and glass fibres on the fracture resistance of composite resins. Method: Rhombic test specimens 2 × 2 × 25 mm for five groups were prepared. They were divided into the controls group, group I which is Targis and group II which is TPH Spectrum, tested groups, group III which is glass fibres (Vectris)/ Targis, group IV which is polyethylene (Connect)/ TPH Spectrum/ silane coupling and group V which is polyethylene (Connect)/ TPH Spectrum group. All specimens were water stored at 37 ± 1°C for 24 hours and tested dry at room temperature. A three-point bending test was used to measure the fracture resistance. The fractured specimens were analyzed under Image Analyser and Scanning Electron Microscope for load fracture. Results: the data were analyzed using an independent samples t-test for group I and III and one-way ANOVA for groups II, IV and V. An independent samples t-test showed that there were significant differences in fracture resistance between the control group, Targis and test group Vectris/ Targis. The fracture resistance results showed that the mean fracture resistance for Targis was 159.65 MPa, Vectris/ Targis was 177.63 MPa, Connect/ TPH Spectrum was 193.64 MPa, Connect/ TPH Spectrum/ Silane coupling was 175.59 MPa. Conclusions: Placement of glass and polyethylene fibres in the composite resins increased the fracture resistance of both groups. Image analysis and scanning electron microscopy showed the presence of horizontal and vertical fractured lines without catastrophic fracture. Silane coupling agent that was used here showed that there was no added improvement in fracture resistance after treatment with silane coupling on the fibres and composite resins. Study supported by Vote F 0125/2004B.