Evaluation of Bond Strength & Enamel Alterations with the Contemporary Light Cure Orthodontic Adhesives: A Scanning Electron Microscope Study

Introduction: The introduction of acid etch technique in orthodontics has partially eliminated the banding technique due to factors like conservation of band space, prevention of decalcification beneath the loose bands and improved aesthetics and decreased cost. Two paste system, no mix adhesive, light activated direct bonding material and adhesive pre-coated brackets are present modifications of adhesive formulations. Materials and Methods: The sample of this in-vitro study consisted of ninety caries free, intact extracted mandibular first molar teeth. The roots of the teeth were embedded in the centre of a cold cure acrylic. A molar tube of 0.018” Roth prescription with micro etched base was bonded to each molar with three different bonding agents. All the molar tubes were subsequently tested for evaluation of shear bond strength with a universal testing machine. Scanning Electron Microscope (SEM) was used to evaluate the effect of various light cure adhesives on the enamel morphology. Results: Transbond-XT exhibited the highest bond strength (22.6 MPa) closely followed by Transbond Plus SEP (19.6 MPa) and GC Fuji Ortho LC (13.89 MPa). Conclusions: The adequate bond strength of glass ionomers, less deleterious effects on the enamel and sustained fluoride release make it a good option for routine use in orthodontics.