In Vitro Study of Transverse Strength of Fiber Reinforced Composites

Abstract

Objective: Reinforcement with fiber is an effective method for considerable improvement
in flexural properties of indirect composite resin restorations. The aim of this in-vitro
study was to compare the transverse strength of composite resin bars reinforced with preimpregnated
and non-impregnated fibers.
Materials and Methods: Thirty six bar type composite resin specimens (3×2×25 mm)
were constructed in three groups. The first group was the control group (C) without any
fiber reinforcement. The specimens in the second group (P) were reinforced with preimpregnated
fibers and the third group (N) with non-impregnated fibers. These specimens
were tested by the three-point bending method to measure primary transverse strength.
Data were statistically analyzed with one way ANOVA and Tukey's tests.
Results: There was a significant difference among the mean primary transverse strength in
the three groups (P<0.001). The post-hoc (Tukey) test showed that there was a significant
difference between the pre-impregnated and control groups in their primary transverse
strength (P<0.001). Regarding deflection, there was also a significant difference among
the three groups (P=0.001). There were significant differences among the mean deflection
of the control group and two other groups (PC&N<.001 and PC&P=.004), but there was no
significant difference between the non- and pre-impregnated groups (PN&P=.813).
Conclusion: Within the limitations of this study, it was concluded that reinforcement with
fiber considerably increased the transverse strength of composite resin specimens, but impregnation
of the fiber used implemented no significant difference in the transverse
strength of composite resin samples.