Wear and mechanical properties of composite resins consisting of different filler particles

Abstract

To investigate the effects of different fillers and their contents on the wear of composite resins, four composites (CS: non-porous spherical silica, AS: porous spherical silica, AZ: porous spherical zirconium silicate, and IS: non-porous irregular-shaped silica) were experimentally prepared using different fillers (CS, AZ, AS and IS). Simulated occlusal wear and toothbrush wear were evaluated for these composites and their worn surfaces were observed. The mechanical properties (flexural strength, elastic modulus and hardness) of these composites were determined to examine the relationships between wear and these mechanical properties. CS showed the highest occlusal wear, but the lowest toothbrush wear among four composites. AS and AZ had lower occlusal wear than CS and IS, while their toothbrush wear was higher than CS and close to that of IS. All composites showed increase in the occlusal wear as filler content increased. CS and IS showed decrease in the toothbrush wear as the filler content increased, whereas AS and AZ did not. The occlusal wear surfaces of CS and IS had concavities, while those of AZ and AS were relatively smooth with flattened filler. The toothbrush wear surfaces of CS and IS revealed the extrusion of filler from resin matrix, whereas those of AZ and AS were smooth with flattened filler. The toothbrush wear of CS and IS decreased as the mechanical properties increased, whereas those of AS and AZ did not. The occlusal wear of all composites increased as the mechanical properties increased, which would not reflect effects of these mechanical properties.

Surface roughness and filler particles characterization of resin‐based composites

“…Another aspect that might have affected the surface property of the evaluated composites is the shape of their filler particles, since Z100, Supreme Ultra, and Estelite ∑ Quick have spherical/rhomboid fillers, in contrast to the other tested materials, which present irregularly shaped fillers. Tamura, Kakuta, and Ogura () have suggested that irregularly shaped fillers might receive more frictional forces during abrasion than spherical particles, as they have corners and sharp edges that can be easily caught by abrasives and/or toothbrush bristles, which could facilitate their removal and enhance toothbrushing‐induced wear. Besides, EDX analysis (Figure ) showed the composites with smaller fillers tested in this study have an inorganic portion composed by silica and zirconia particles.…”

Effect of filler size and filler loading on wear of experimental flowable resin composites

“…The adhesion between filler and polymerized resin matrix could also be related to the wear resistance of flowable resin composites. Tamura, et al 19 (2013) reported that the filler loading is directly related to the occlusal wear of experimental resin composites containing four types of filler particles, including non-porous spherical silica, porous spherical silica, porous spherical zirconium silicate, and irregularshaped silica. However, the mechanical properties tested (flexural strength, elastic modulus, and Vickers hardness) showed no correlation with the occlusal wear.…”

Factors influencing mechanical and wear performance of dental composite: A review

“…On the other hand, the increased in filler loading and decreased in filler size improves wear resistance as well as aesthetics of dental composite [55][56][57][58]. In a recent work, the effects of different shapes, surface textures, structures and content of nanoalumina filler particles on the wear and mechanical properties on simulated occlusal wear and toothbrush wear were investigated [59]. It was concluded that the incorporation of nanofiller increased both the hardness and wear resistance of the dental composites and they also produced better polished surface than micro-filler.…”