Aim: The aim of this study is to evaluate the effect of dental prophylaxis techniques on surface roughness of composite resins. Materials and methods: A total of 36 nanohybrid resin composite test specimens were fabricated and divided into three groups (n = 12). They were kept in distilled water at 37°C for 24 hours and submitted to the finishing and polishing technique. For the prophylactic techniques, in group G1, a mixture of pumice stone and distilled water was used with the aid of a rubber cup; in group G2, Herjos-F prophy paste was used with a rubber cup; and in group G3, a bicarbonate jet spray was used. Afterward, all the samples were repolished using the Soflex pop-on disks. A roughness meter was used to measure surface roughness at three points in time: Before the prophylactic techniques (1st evaluation), afterward (2nd evaluation), and following repeat polishing (3rd evaluation). Results: It was found that roughness values changed significantly between the 1st and 2nd evaluations (p < 0.05) and between the 2nd and 3rd evaluations (p < 0.05), showing that the change in roughness depended on the type of prophylactic treatment. Roughness was significantly higher after the bicarbonate jet (p < 0.05). Conclusion: Prophylaxis using the sodium bicarbonate jet significantly altered the roughness of nanoparticle-reinforced resin. Clinical significance: Dental prophylaxis is the most common practice employed to remove bacterial plaque and other coatings. However, one side effect of the cleaning may be a rougher surface subject to degradation and staining. The correct use of prophylactic devices and avoiding prolonged use on resin restorations reduce surface roughness.