Objective: The aim of this study was to compare the two-body wear resistance and the surface roughness of three different bulk-fill composite resins and a conventional resin composite materials with against human enamel and porcelain.
Materials and methods:
Eighty cylindrical specimens were fabricated from three bulk fill resin composites and one conventional composite : group I (n=20) discs of Sonic, group II (n=20) discs of Tetric Evoceram , group III (n=20) Filtek and group IV(n=20) Filtek Z250. All specimens were subjected to a programmable logic controlled equipment was used to record the two-body wear of tested composites. Enamel and porcelain were used as antagonists. Wear were determined by weight loss and images analysis software were evaluated the tested samples surface topography. All data were statistically analyzed by Kruskal-Wallis test followed by Dunnʼs and Wilcoxon signed-rank test.
Result: With enamel and porcelain antagonist; there was no statistically significant difference between weight loss and ΔRa of the four materials.
Porcelain antagonist showed statistically significantly higher weight loss than enamel antagonist with Tetric Evo Ceram, Sonic fill, Filtek as well as Z250 composite types;
While with Filtek, there was a statistically significant difference between ΔRa of the two antagonists(P-value = 0.025, Effect size = 2.714). Enamel showed an increase in roughness while porcelain showed a decrease in roughness.

Conclusion
Nanofillers bulkfill resin composite did not significantly influence the wear resistance. Porcelain antagonist showed more wear than enamel antagonist. However, enamel showed decrease the roughness