Evaluation of the shear bond strength of lingual brackets manufactured by three different processes using two different adhesive primers: An in vitro study

Abstract

The most important procedures in orthodontic practice is bonding brackets to tooth enamel. The adhesive force should be enough to keep the bracket in position throughout the orthodontic treatment, but not strong enough to cause damage on its debonding to the enamel. Lopez, as well as Reynolds, suggests that shear strength should be 6-8. [1] Equivalent traction would be about 5 MPa.Since the inception of lingual orthodontics, it was necessary that orthodontist had to think of an optimal straight wire technique because of the reduced interbracket span on the lingual surfaces with its associated biomechanical consequences and the problems encountered while working on the lingual surface and also because of the anatomical irregularities of the teeth on that side. The introduction of computer-aided design/ computer-aided manufacturing (CAD/CAM) technology has made it possible to produce brackets with an adaptable base and with the necessary precision for all lingual surfaces, also it became obvious that there was a need for indirect bonding involving bracket positioning on cast models. Three popular indirect bonding systems are the Torque Angulation Reference Guide (TARG), Class and Pacon systems.Shear bond strength (SBS) is the main factor, which has to be considered in the evolution of bonding materials. The bond strength of the orthodontic bracket must be able to withstand the forces applied during the orthodontic treatment.