The aim of this study To compare in vitro shear bond strength (SBS) of different orthodontic adhesives in and rebonding metal brackets after preparing their bases mechanically. Material and methods:Sample consisted of 40 extracted first premolars, randomly divided into two groups (n=20),.Adhesive removed by tungsten carbide bur later the brackets were rebonded. The tests were performed in a tecnotest (6kN) SBS testing machine, at a speed of 1 mm/min. It was found that the mean shear bond strength of Reseliencewas 19.25 MPa and that of Heliosit orthodontic was 10.25MPa.We foundthat the mean shear bond strength of rebonding forReselience was 13.70 and 7.95 forHeliosit.The t-test revealed that there was a significant difference between the shear bond strength of the two groups. We found a significant difference between bonding and rebondingfor Reselience,while there was no significant difference between bonding and rebonding for Heliosit.