Effect of short glass fiber reinforcement on wear resistance and fracture strength of high-viscosity glass ionomer cements

Context: The longevity of a posterior restorative material is highly dependent on its wear resistance and ability to endure occlusal stresses. Short-discontinuous fiber-reinforced glass ionomer cements (GICs) have shown promising enhanced mechanical properties. Aim: The aim of the study was to evaluate the influence of discontinuous E-glass fiber reinforcement on the wear resistance and fracture strength of two high-viscosity GICs (HVGICs). Materials and Methods: Standardized Class I cavities on 120 extracted human mandibular molars were grouped ( n = 24 each) and restored either with (1) EverX Posterior, (2) GC Gold Label Hybrid, (3) GC Hybrid + fiber, (4) Shofu RX Ease, or (5) Shofu RX Ease + fiber. Discontinuous silanized E-glass fibers (5 wt%) were manually blended into the GIC powders. Twelve samples per group underwent thermocycling and chewing simulation for wear resistance assessment, while the remaining samples were mechanically loaded and tested for fracture strength using a universal testing machine. Statistical analysis used one-way ANOVA and Tukey’s post hoc test (α =0.05). Results: GC Gold Label Hybrid with fiber showed the lowest mean percentage weight loss, indicating superior wear resistance, while Shofu RX Ease exhibited the highest percentage wear (P = 0.0001). However, the addition of fiber did not significantly affect the wear resistance of GC Gold Label Hybrid (P = 0.3736). In contrast, fiber reinforcement significantly increased the fracture strength in both test groups (P = 0.0001). Conclusion: Short discontinuous fiber reinforcement significantly improves fracture strength and wear resistance of HVGICs. The wear of the GC Glass hybrid was not affected with fiber reinforcement.