Evaluation of Two-Body Wear of Nanocomposites With Different Filler Morphology and Composition Using White-Light...

The aim was to compare the two-body wear behavior of four nanocomposites used for enamel replacement.

Nanocomposite specimens (Estelite Asteria [EA], Enamel Biofunction [EBF], Neospectra [NS], Clearfil Majesty [CM]; n = 8 for each, diameter = 10 mm, height = 1.5-2 mm) were prepared in a custom-made mold according to the manufacturer's instructions. The degree of conversion (DC) was measured by Fourier transform infrared spectroscopy. Vickers hardness (VH) was measured on the top and bottom surfaces, and the VH ratio (VHR) was calculated. The specimens were aged using a thermocycling machine (10,000 cycles), followed by 120,000 chewing cycles. The mean volume loss (MVL), maximum wear depth (MWD), and surface roughness (SR) were assessed with a white-light interferometer. The tested surfaces before and after the wear test, along with the morphology of extracted fillers, were evaluated using scanning electron microscopy (SEM). Statistical analysis-ANOVA, Levene, Tukey, and Tamhane tests-was performed with SPSS Statistics version 28.

CM exhibited a significantly higher VH compared to the other nanocomposites, both before and after aging. It also showed lower MVL, MWD, and SR than the other three tested nanocomposites.

VH and wear behavior are significantly affected by the filler parameters of nanocomposites.

This study may assist clinicians in selecting resin-based composite (RBC) for occlusal rehabilitation. Based on this in vitro study, CM exhibited a lower wear rate than the other tested RBCs; therefore, it is worth considering its use for patients with higher bite forces.