Objective: The goal of this in vitro investigation is to assess laser irradiation and phosphoric acid etching effects on the dentinal surface topography. Materials and Methods: A total of 48 sound human premolars extracted for orthodontic purposes were included in this study. Teeth were divided into four groups (n = 10), G1 without surface treatment, G2 etched with phosphoric acid 37% for 15 seconds, and G3 and G4 were treated with an Er, Cr:YSGG laser at the following settings: 1W, 1.5W, respectively with set other laser parameters at 20 HZ and 10% air/water ratio. The effects were evaluated using SEM, AFM, and contact angle. Results: AFM and SEM images showed changes in the surface topography of the dentin with an increase in the surface roughness measurements and devoid from smear layer in the laser-treated groups compared to the control and phosphoric acid-treated groups. Also, highly significant differences (p≤0.01) were shown in the laser irradiation groups, specifically G3 with 1W, when compared with others considering contact angle measurement. Conclusion: Er, Cr: YSGG laser can be used as an alternative to conventional phosphoric acid etching for etching and preparing dentin surfaces prior to restoration or bracket placement.