Long-term Durability of the Dual-cure Resin Cement/Silicon Oxide Ceramic Bond

To determine the effects of using a ceramic primer, ceramic bonding agent, or a combination of primer/bonding agent on the long-term durability of the dual-cure resin cement/silicon oxide ceramic bond. Ceramic blocks (Vita Celay Blanks), A2M, were cut into 1-, 2-, and 3-mm-thick slices and polished using 600-grit SiC paper. Group 1 consisted of pairs of 1- and 3-mm-thick slices, and Group 2 of pairs of 2- and 3-mm-thick slices. Ceramic surfaces were treated with 40% phosphoric acid and silanated using one of three treatments: (1) Clearfil Liner Bond 2V Primer (2V Pr) and Porcelain Bond Activator (PBA), (2) Liner Bond 2V Primer/PBA and Liner Bond 2V Bond (2V Pr + Bd), and (3) Clearfil Photo Bond/PBA (P Bd). They were then bonded with a dual-cure resin cement (Panavia F) and light-cured for 20 s from each of six directions. After 24 h water storage at 37°C, 0.7-mm-thick slabs were serially sectioned. Immediately thereafter, after one and six weeks, and after one year of water storage, two slabs were randomly selected from each subgroup and sliced into beams for the microtensile bond strength (µTBS) test. Data were evaluated with three-way ANOVA and Fisher's PLSD test (p 0.05) and failure modes determined using a laser-scanning confocal microscope. After 1 day, there were no significant differences between 2V Pr, 2V Pr + Bd, and P Bd (p > 0.05), whereas after one year, significant differences were found (p 0.05). For Group 1, the µTBS of P Bd after one year of water storage was similar to that after one day. In both groups, µTBS of 2V Pr and 2V Pr + Bd significantly decreased over time (p 0.05), which was accompanied by an increase in the percentage of complete adhesive failures. The chemical composition of the multicomponent ceramic primer/bonding agent significantly affects the long-term durability of the dual-cure resin cement/silicon oxide ceramic bond. The presence of water in a ceramic primer has a significant detrimental effect on resin-ceramic bond durability. In addition, the thickness of the ceramic restoration influences dual-cure resin cement/ceramic bond durability.