<p>This study aimed to evaluate changes in surface roughness after simulated toothbrushing in conventional and additively manufactured resin-based restorative materials using different dentifrices. Four conventional resin composites (flowable, ormocer-based, supra-nano-filled, and bulk-fill) and two additively manufactured restorative resins were included. Specimens were subjected to five brushing conditions: distilled water (control), fluoridated, bioactive, probiotic, and whitening dentifrices (<i>n</i> = 10). Toothbrushing was performed for 5,000 cycles under a 200-g load. Surface roughness (Ra) was measured before and after brushing using a contact profilometer, and surface morphology was qualitatively assessed by scanning electron microscopy. Data were analyzed using two-way analysis of variance followed by post hoc tests (α = 0.05). No significant main effect of restorative material (<i>p</i> = 0.540) or dentifrice type (<i>p</i> = 0.645) was observed; however, a significant material–dentifrice interaction was detected (<i>p</i> &lt; 0.001). Pairwise comparisons revealed material-dependent differences in roughness change following brushing. Within the limitations of this in vitro study, post-brushing surface roughness was influenced by the specific combination of restorative material and dentifrice. These findings may be relevant when selecting restorative materials and dentifrices for clinical use.</p>