Objective. To evaluate the wear (roughness) and topographic changes of the Wave One Gold primary and Reciproc Blue R25 files after instrumentation at 3, 6 and 9 uses in curved canals. Methods. Ex vivo study, consisting of 10 new Reciproc Blue R25 and 5 Wave One Gold primary reciprocating files and 46 mandibular first molars with severe curvature. Molars were divided into 2 groups (23 molars in each group): group 1 Reciproc Blue R25/.08 and group 2 Wave One Gold Primary (25/.07). Reciprocating files from the two groups were analyzed with the contact profilometer at 0, 3, 6 and 9 uses. The measurement was made in the apical, middle, and coronal thirds, and in each analysis, 2 files were observed with the Scanning Electron Microscope. Subsequently, the analysis in the SPSS version 26 IBM ® program was performed using t-Student and Anova tests for normality (p<0.05). Results. There is no...