This research compares the effect of different rotary instruments for finishing (tungsten carbide laminated drill or diamond drill) on composite restorations and on the interface between enamel and composite. The composite resins used were HRi (R) (Micerium)-nanoparticle dental resin and Synergy (R) D6 (Coltene) nanohybrid resin. Surface roughness was evaluated using optical profilometry and studied with SensoScan software 5.3 (SensoTech, S.L.). Statistical analysis was performed using IBM SPSS software (v.23) to identify significant differences on the roughness surface on finishing and polishing procedures.