Effect of Preheating on the Surface Roughness of Nanofilled and Nanohybrid Resin Composites: An In Vitro Study

Abstract

Background: Resin composites can have their viscosity reduced and their polymerization altered by preheating; nevertheless, the effect of preheating on surface roughness may be composition-dependent.

Objective: The purpose of this experiment is to determine how preheating affects the surface roughness of resin composites that contain nanofillers or nanohybrids. To evaluate the effect of preheating on the surface roughness of nanofilled and nanohybrid resin composites. Materials and Methods: Four groups (n=12) were established based on material and temperature: either preheated to 70°C or at room temperature (24°C). Forty-eight disc-shaped specimens (8 mm × 2 mm) were made from Filtek Z350 XT and Tetric N-Ceram. Using a contact profilometer, we assessed the surface roughness (Ra) after standard grinding and polishing using Sof-Lex disks. We used Tukey's post hoc test (α=0.05) and two-way ANOVA to examine the data. Results: The mean Ra was 0.2717 ± 0.0035 µm for the preheated Filtek Z350 XT and 0.2262 ± 0.0034 µm for the room-temperature Tetric N-Ceram. There was a strong relationship between composite type and roughness (p<0.001), with Filtek Z350 XT showing greater values than Tetric N-Ceram. There was a slight but statistically significant increase in Ra (p=0.009) due to preheating. Preheating had no statistically significant effect on the material. Neither the heated nor room-temperature groups differed significantly when compared using Tukey's method.

Conclusion: Preheating has less of an effect on surface roughness than material composition. Preheating resulted in a minor increase in roughness, whereas Tetric N-Ceram made the polished surface much smoother.