Effect of resin cement selection on the microtensile bond strength of adhesively veneered 3Y-TZP

Abstract

Objective. The aim of this study was to investigate the effect of resin cement selection on the microtensile bond strength (μTBS) of adhesively veneered 3Y-TZP. Materials and methods. 3Y-TZP discs were fabricated from commercial powders and treated by sandblasting and zirconia primer. Porcelain discs were sectioned from a feldspathic block and conditioned with 5% HF and silane agent. Pre-treated surfaces of zirconia and porcelain discs were bonded together using one of the three following resin cements: Multilink N (MN), Panavia F (PA) or RelyX Unicem (RU), respectively. After light-curing the joined discs were cut into microbars where 15 microbars per group were randomly chosen for μTBS test until failure occurred (24 h storage in water in advance, crosshead speed of 0.5 mm/min). The data were analysed by one-way ANOVA and Tukey's test (p < 0.05). Fractured zirconia surfaces were examined using both a stereomicroscope and scanning electron microscope to identify the failure mode. Results. Significant differences in the μTBS values among three groups were found (p < 0.001) and the descending order was PA, RU and MN. No zirconia or feldspathic failure occurred, but the zirconia/cement interfaces suffered from fracture for all samples. Cement cohesive failure and/or feldspathic/cement interfacial failure sometimes were involved. Failures were mainly adhesive for RU, while they were mixed for MN and PA. Conclusion. When using the adhesive veneering method, Panavia F offers better bond strength than Multilink N or RelyX Unicem, which is probably due to the content of the 10-methacryloyloxydecyl dihydrogenphosphate (10-MDP) monomer.

Key Words::

• adhesion
• bond strength
• microtensile
• resin cement
• zirconium oxide

Acknowledgements

The work was supported by the China Scholarship Council (CSC). The authors express their thanks to Miss Bu Ying and Dr Wang Fangping for technical support. The authors are grateful for the critical review of Dr Kocjan Andraž. They also acknowledge the partial supply of materials from Ivoclar Vivadent and Kuraray Medical.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.