Quantitative wear and wear damage analysis of composite resins in vitro

The aim of this study was to investigate volume loss and worn surfaces' morphologies of eight composite resins: Durafill VS (DUR), Clearfil AP-X (APX), Filtek Z250 (Z250), Filtek Supreme XT (FIL), Kalore (KAL), MI Flow (MFL), Venus Diamond (VED) and Venus Pearl (VEP). Disc-shaped specimens were fabricated and mounted in a ball-on-disc wear testing machine and abraded in water or with the third-body media, poppy seed slurry and polymethyl methacrylate (PMMA) slurry. Volume loss (n=5) was determined after 50k sliding cycles, and analyzed using two-way ANOVA (α=0.05). The worn surfaces were examined with SEM. Two-way ANOVA suggested significant interaction between composite and wear condition. DUR, KAL and MFL showed low wear in water. DUR, Z250 and FIL showed moderate wear with PMMA slurry, whereas APX, KAL and MFL were deeper abraded. Under the action of poppy seed slurry DUR proved high volume loss. SEM showed that Z250, FIL and MFL were uniformly abraded in water. KAL and MFL with poppy seed were heavily destructed, whereas VED and VEP appeared very smooth. KAL and MFL abraded with PMMA slurry showed many cracks, but VEP remained crack-free and smooth. Volume loss and worn surfaces' morphologies varied with type of composite and third-body media used. [Display omitted] •Wear of three conventional and five nanofiller containing composites was determined.•Ball-on-disk sliding wear was evaluated in water, in PMMA and poppy seed slurries.•Volume loss and morphology of wear traces were determined after 50k loading cycles.•Third-body action is the main wear mechanism resulting in fatigue-related failure.•Initially wear is mainly due to 2-body attrition, consecutively to 3-body abrasion.