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 (μSBS) 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 μSBS 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 μSBS (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 μSBS for Groups 1 and 2, along with an increase in adhesive failures across all groups.

Conclusions

Prior application of silane did not increase the μSBS between Scotchbond Universal Plus and ceramic, and there was degradation at the bond interface over time.

Clinical Significance

Prior 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.