Effect of Surface Treatments on the Resin to Zirconium-Based Ceramic

Objectives: The development of zirconium core via CAD/CAM system has allowed the all ceramic restorations to be applied to almost all fixed prosthesis. But, the increased strength has been reported to increase in proportion with the bond strength of cement, and recently, the “Tribochemical system" which increases the bond strength through, silica coating and silanization has been introduced. The purpose of this study was to compare the Rocatec systemTM(3M/ESPE) and CoJet systemTM(3M/ESPE) with the traditional acid etching and silanization method of the zirconium based ceramic.

Methods: 50 In-Ceram Zirconia discs were fabricated and embedded in resin, group 1 was treated with glass-bead blasting and cleaning, group 2 was treated with 20% HF for 10 minutes and silanized, group 3 was treated with the Rocatec systemTM, and group 4 was treated with the CoJet systemTM. Each group was comprised of 10 specimens. The specimens were cemented to resin blocks with Super-Bond C&B. The shear bond strength was measured with the Instron® 8871. The surface character was observed via SEM(X2000).

Results: According to SEM results, there were little difference between group 1 & group 2, but in group 3 and 4, silica coating was detected and there was increase in surface roughness. The shear bond strength decreased in the order of group 3(46.28MPa), group 4(42.04MPa), group 2(31.56MPa), and group 1(27.46MPa) and there was significant differnce between group 1&2 and group 3&4(p<0.05).

Conclusion: From the results above, it can be considered that the conventional method of acid etching and silane treatment cannot increase the bond strength with resin cements, and that by applying the "Tribochemical system" of Rocatec systemTM and CoJet systemTM, we can achieve a stronger all ceramic restoration.