Is additional silane application necessary for a new silane-containing universal adhesive to bond to glass ceramics?

Objective To evaluate the in vitro influence of prior silane application on the microshear bond strength (mu SBS) of Scotchbond Universal Plus to glass ceramic. Materials and Methods Thirty blocks of lithium disilicate ceramic were etched with hydrofluoric acid for 20 s and distributed into Group 1 (no silane and no adhesive), Group 2 (adhesive), Group 3 (silane + adhesive). Three cylinders of resin cement were made on each ceramic block. Five blocks (n = 15 cylinders) were subjected to the mu SBS test after 24 h, and the other five blocks (n = 15 cylinders) were tested after 6 months of water storage. Results According to two-way ANOVA, followed by Tukey's test, the means of mu SBS (MPa), denoted by different letters, show significant differences (p < 0.05): after 24 h-Group 1 (31.7)(B), Group 2 (43.3)(A), and Group 3 (31.3)(B); after 6 months-Group 1 (14.8)(B), Group 2 (33.6)(A), and Group 3 (30.3)(A). After 6 months of storage, there was a significant decrease in mu SBS for Groups 1 and 2, along with an increase in adhesive failures across all groups. Conclusions Prior application of silane did not increase the mu SBS between Scotchbond Universal Plus and ceramic, and there was degradation at the bond interface over time. Clinical SignificancePrior application of a silane agent is not necessary when using Scotchbond Universal Plus for bonding to glass ceramics. Regardless of the prior application of silane, there is degradation at the bond interface over time.