Three-Body Wear of Flowable Short-Fiber Reinforced Composite: Effect of Food Simulating Media

Objectives: The aim was to investigate the three-body wear of a short-fiber reinforced flowable composite (everX Flow, Dentin shade, GC, Japan) using various food simulating media.
Methods: The composite was placed and cured in cavities (20 mm length x 10 mm width x 2 mm depth) prepared in an acrylic resin block. The surfaces were then polished flat using a sequence of #1200- to #4000-grit silicon carbide papers. After one day of water storage (37 °C), three-body wear test was conducted with 15000 chewing cycles using a dual-axis chewing-simulator. The test involved a weight of 2 kg, equivalent to a 20 N chewing force, with a frequency of 1.5 Hz. As an antagonist, a Steatite ball with a diameter of 6 mm was utilized. Specimens were mounted within a lower plastic sample holder, which contained either water with no seeds (control), an aqueous slurry of poppy seeds, an aqueous slurry of poppy seeds with PMMA, an aqueous slurry of nut shells, or an aqueous slurry of millet seeds for simulating three-body wear, respectively. Wear depth was assessed (n=6/ per group) using a 3D optical profilometer, and surface wear behavior was evaluated with SEM. The wear depth values underwent statistical analysis through a one-way analysis of variance (ANOVA) followed by Tukey HSD test (α = 0.05)
Results: The composite used exhibited varying wear behavior, ranging from 7 to 38 µm (p<0.05). The highest wear depth values were observed when nut shells and poppy seeds with PMMA were employed as food simulating media. In contrast, the lowest values (p<0.05) were recorded when a slurry of millet seeds was used. Notably, the use of poppy seeds alone did not have a significant (p > 0.05) impact on wear, as the behavior resembled that of the water-only group.
Conclusions: The data indicates that the choice of food simulating media significantly influences the wear behavior of short-fiber reinforced composite. Notably, everX Flow exhibited minimal surface wear when subjected to millet seeds as the third-body medium.