In oral orthodontic treatments, achievement ofa good adhesion between brackets and teeth surfaces isessential. One way to increase adhesion is to apply a surfacetreatment of teeth facing surfaces through the projectionof abrasive particles to produce a surface roughnesswhich improves adhesion of the bracket to the tooth,because of the significantly increased contact between thetwo surfaces. The effect on adhesion through the use of thistechnique in different types of brackets, as well as throughthe use of different blasting particles, however, is yet notwell described. In this study we have included three typesof brackets which are commonly used in orthodontictherapies (two of them a mesh-type and the third one amicro-milled type) with a contact surface area of 11.16,8.85 and 6.89 mm2 respectively. These brackets were usedcombined with a sandblasting treatment with two differenttypes of abrasive particles, alumina (Al2O3) and siliconcarbide (SiC) and applied to natural teeth in vitro. Theabrasive particles used are bio-compatible and usually usedin achieving increased roughness for improved adherencein biomedical materials. Sandblasting was performed at 2bars for 2 s; three particle sizes were used: 80, 200 and600 lm. Non-blasted samples were used as control. Eachof the pieces were cemented to natural teeth with a selfcuringcomposite. Samples were stored in physiologicserum at 5 C temperature. Tensile tests were performedwith a universal testing machine. Brackets treated withsandblasted particles were measured to have an increasedadhesion as compared to the control sample. The highestbond strength was measured for samples sandblasted withalumina particles of 80 and 200 lm combined with micromilledbrackets. The recorded stresses did not exceed thetensile strength of tooth enamel.