This research was designed to compare the thickness and the depth of penetration of two resin-based materials (Icon and one-step self-etch adhesive (Single Bond Universal)) in artificial white spot lesion (WSL) created on caries-free molar teeth, without and with surface treatment prior application of the resin-based materials at different storage time (one day, one week and one month).  The 126 samples were randomly divided into three equal main groups (n=42) according to the resinous material (M); Group 1 (M1) was considerate to be control group. Group 2 (M2) was restored with Icon. Group 3 (M3) was restored with Single Bond Universal. Each group was divided into two equal subgroups (n=21) according to the surface treatment (W); Where the first subgroup (W1) was subjected to surface treatment while the second subgroup (W2) was without surface treatment. The samples were further divided into three divisions (n=7) according to the storage time (S). Division 1 (S1) was stored for one day. Division 2 (S2) was stored for one week. Division 3 (S3) was stored for one month. Each resin-based material was applied after creation of white spot lesion, according to the manufacture instruction. Buccal and lingual surface of each sample was used to measure the thickness of the resin-based materials using Optical profilometer while confocal laser scanning microscopy (CLSM) was used to measure the depth of penetration. The result of this study reveals that: the surface treatment prior application of Icon group improve the degree of penetration depth to get the highest value compared with the other groups while the thickness of the untreated surface prior application of Icon groups gives the thickest value compared with the thickness of the other groups.  Conclusion; Icon is the best choice for treatment of (WSLs).