To evaluate changes in surface characteristics of two different resin composites after 1 year of water storage using a profilometer, Vickers hardness, scanning electron microscopy (SEM), and atomic force microscopy (AFM). A total of 46 composite disk specimens (10mm in diameter and 2mm thick) were fabricated using Clearfil Majesty Esthetic and Clearfil Majesty Posterior (Kuraray Medical Co, Tokyo, Japan). Ten specimens from each composite were used for surface roughness and microhardness tests (n=10). For each composite, scanning electron microscope (SEM, n=2) and atomic force microscope (AFM, n=1) images were obtained after 24h and 1 year of water storage. The data were analyzed using two-way analysis of variance and a post-hoc Bonferroni test. Microhardness values of Clearfil Majesty Esthetic decreased significantly (78.15-63.74, p=0.015) and surface roughness values did not change after 1 year of water storage (0.36-0.39, p=0.464). Clearfil Majesty Posterior microhardness values were quite stable (138.74-137.25, p=0.784), and surface roughness values increased significantly (0.39-0.48, p=0.028) over 1 year. One year of water storage caused microhardness values for Clearfil Majesty Esthetic to decrease and the surface roughness of Clearfil Majesty Posterior increased. AFM and SEM images demonstrated surface detoration of the materials after 1 year and ensured similar results with the quantitative test methods. SCANNING 38:694-700, 2016. (c) 2016 Wiley Periodicals, Inc.