Erosive-Abrasive Effects on Surface, Mechanical, and Optical Properties of 3D-Printed Resin Composites for Prosthetic Applications

To evaluate the effects of erosive-abrasive challenges on the microhardness (SH), surface roughness (SR), gloss (Gs), surface morphology, and color stability (ΔE) of 3D-printed resin composites for use in dental prosthetic restorations.

Rectangular specimens (10×10×2 mm³; n=10) were fabricated using digital light processing (DLP) 3D printing, post-polymerization (post-curing), polished, and standardized. Specimens were subjected to an erosive-abrasive protocol involving citric acid immersion and simulated toothbrushing. SH, SR, and Gs were measured before and after cycling. Additional specimens were immersed in coffee to assess ΔE, and surface morphology was analyzed by scanning electron microscopy. Data were statistically analyzed (α=0.05).

Significant differences in SH were observed among materials at baseline and after cycling (p < 0.001). The nanohybrid resin composite showed the highest initial values but a significant reduction after the challenge, whereas nanosilicate and zirconia-containing composites remained stable. SR did not differ among groups, although only the nanohybrid resin composite showed a significant increase after toothbrushing. Gloss was influenced by material and time, with the nanosilicate resin composite maintaining the highest values after cycling, although all materials exhibited a reduction after the challenge. No differences in ΔE were observed under a white background, whereas significant differences were found under a black background, with higher variability for the nanosilicate resin composite.

The response of 3D-printed resin composites to erosive-abrasive challenges was material-dependent. Nanohybrid composites showed greater susceptibility to degradation, whereas zirconia-containing and nanosilicate resin composites demonstrated a more favorable response under all evaluated parameters. These findings highlight the importance of material selection for esthetic outcomes and potential long-term performance in dental prostheses; however, extrapolation to clinical longevity requires further investigation.