The Effect of Two Adhesive Promoters on Bond Strength of Ultra-Translucent Zirconia to Two Resin Cements.

Abstract

Statement of the problem:The increased amount of crystals in zirconia ceramics and the absence of glass make them resistant to acid etching and chemical bonding through traditional silane application. Alternative durable bonding techniques between zirconia and resin cement are still mandatory. Objective: This study was conducted to investigate the effect of two adhesive promoter types and two resin cements on the shear bond strength of sandblasted ultra-translucent zirconia plates to resin cement. Materials and Methods: BruxZir anterior Zirconia blank was sliced to obtain forty-two ultra-translucent zirconia plates, followed by their sintering. All the plates were sandblasted using 50 µm alumina particles. Plates were divided into three groups according to the type of adhesive promoter: Group A: no primer, Group B: coated with zirconia primer, and group C: coated with a universal bonding agent. One plate from each group was examined under Scanning Electron Microscope. Half of the plates in each group were bonded to conventional composite resin cement while the other half were bonded to Phosphate containing one following the manufacturers' instructions. All plates were stored in an incubator containing distilled water at 37 ºc for 1 week. Shear bond strength test was performed using universal testing machine. Data obtained were analyzed statistically. Results: The application of Z prime and bonding to conventional resin cement resulted in the highest shear bond strength values (19.58 MPa) followed by no primer application and bonding to phosphate resin cement (15.8 MPa). Universal bonding agent showed the lowest bond strength values with both resin cements. Conclusions: Application of MDP-containing primer showed the highest bond strength with conventional resin cement while the universal adhesive showed weak bond strength with both resin cements. Resin cements reacted almost equally when used directly on zirconia without primer application.