Background: Orthodontists are faced with the challenge of bonding to various types of restorations like amalgam, gold, composite and porcelain. Several methods have been suggested to bond brackets on porcelain with different surface conditioning methods.
Aims & Objectives: The aim of this in-vitro study was to compare the shear bond strength of several modalities that have been advocated for bonding orthodontic brackets to porcelain and further evaluate the fracture site and the bonding surface for porcelain fracture and residual adhesive under stereomicroscope.
Materials & Method: Eighty samples of porcelain fused metal ceramic were divided into eight groups, subjected to different surface conditioning methods and brackets were bonded onto it. Mean Shear bond strength and ARI Score were evaluated after debonding.
Discussion: All the shear bond strength values in the present study were in the optimal range of 6-8 MPa. Mechanical deglazing and chemical surface conditioning followed by silane application enhanced the bond strength due to the chemical link between them. ARI revealed minimal surface damage of the sample when examined under stereomicroscope.
Summary & Conclusion: This exhaustive study revealed that the ideal surface conditioning would be to sandblast, etch with HF acid and apply silane coupling agent, which yielded the maximum shear bond strength. The other alternative would be to roughen the surface with diamond bur followed by silane application or to use ProphyJet followed by silane application. All these methods yielded clinically significant mean shear bond strength with minimal damage to porcelain requiring minimal polishing post debonding