Comparison of Shear Bond Strength of Edgewise Bracket Bonded to Composite Restoration by Using Three Regimes of Orthodontic Adhesive Systems (In Vitro Study)

Abstract

Introduction: Direct bonding of orthodontic attachment has removed some of the esthetic concerns many adults previously had when considering orthodontic therapy. With an increase in adult treatment comes the challenge of direct bonding to non-enamel surface, such as composite restoration. This in vitro study was designed to compare the effect of using three regimes of orthodontic adhesion systems on shear bond strength when bonded edgewise brackets to composite restoration. Materias and methods : The study samples were randomly divided into three groups (30 specimens each).Group I using resilience orthodontic adhesive material (4thgeneration) consist from acid-etching, primer and adhesive; group II using heliosit orthodontic adhesive (1stgeneration) consist from acid-etching and adhesive without bonding agent; group III using self-etching/self-bonding orthodontic adhesive (Totalcem) (7thgeneration). Results: The result of the study showed that the light cured bonding adhesive resilience orthodontic (group I) has the highest mean of shear bond strength (33.7 Mpa) followed by dual-cure automix bonding self-etch/self-bonding adhesive resin cement (23.6 Mpa). While the light cured bonding adhesive heliosit showed the lowest mean of shear bond strength (18.04 Mpa). The cohesive failure (score 2) was the predominant mode of the bond failure in group (I) (4thgeneration) of this study, also the adhesive– composite interface failure was the predominant especially in group (II) (1stgeneration). In group (III) (7thgeneration) while the adhesive -composite interface failure was predominant, but cohesive failure (score 2) and composite detachment (score 4) was found but in less percentage if compared with adhesive–composite interface failure in the same group.