The influence of adhesives and the base structure of metal brackets on shear bond strength.

OBJECTIVE

The objective of this study was to investigate the shear bond strength of compound made of tooth enamel, adhesive, and brackets for certain material combinations according to the DIN 13990-2 standard.

MATERIALS AND METHODS

We examined a combination of the following materials on permanent bovine incisors: (1) adhesives: Light Bond™ and Phase II® (both produced by Reliance Orthodontic Products, Itasca, IL, USA), Transbond XT™ (3M Unitek, Monrovia, CA, USA), (2) brackets: Carriere®, Euro Midi Classic, Midi Low Friction (all from Ortho Organizers, Carlsbad, CA, USA). The discovery® bracket (Dentaurum, Ispringen, Germany) served as the reference. According to the DIN standard, the teeth were embedded, adhesive was applied and they were then put into storage. This was followed by shear tests in a material testing machine with the shear force acting directly on the bracket base in the occlusal-gingival direction. Finally, the Adhesive Remnant Index was determined.

RESULTS

We observed the greatest shear bond strength (mean value) from the combination of Carriere® and Transbond XT™ (17.4 N/mm(2)), and the lowest from the combination of Euro Midi Classic and Phase II® (12.8 N/mm(2)). There were significant differences in the various material combinations. The values obtained from the measurements of discovery® together with Transbond XT™ agreed very well with the results of previous investigations.

CONCLUSION

The combinations of brackets and adhesives investigated in this study according to DIN standard 13990-2 provided a satisfactory result for clinical use.