Effect of prior silane application on the bond strength of a universal adhesive to a lithium disilicate ceramic

Statement of problem. Universal adhesives combine silane and various monomers in a single bottle to make them more versatile. Their adhesive performance is unclear. Purpose. The purpose of this in vitro study was to assess the effects of an additional silane application before using a universal adhesive on the adhesion between a disilicate glass ceramic and a composite resin by using a microshear bond strength test (mu 5BS) and fracture analysis immediately and after thermocycling. Material and methods. One hundred lithium disilicate glass ceramic disks were divided into 10 groups for bond strength testing according to the following 3 surface treatments: silane application (built-in universal adhesive or with additional application), adhesive (Adper Single Bond Plus [SB, 3M ESPE], Scotchbond Universal Adhesive [U, 3M ESPE], and mixed U with Dual Cure Activator [DCA, 3M ESPE]); or thermocycling (half of the specimens were thermocycled 10 000 times). After surface treatment, 5 resin cylinders were bonded to each disk and submitted to a mu SBS test. The failure mode was analyzed under a stereomicroscope and evaluated by scanning electron microscope and energy-dispersive x-ray spectroscopy. Data from the mu SBS test were analyzed by 3-way ANOVA followed by the Tukey HSD post hoc test (alpha=.05). Results. An additional silane application resulted in a higher mu SBS result for all adhesive groups (P <.05). Conclusions. Ceramic surface treatment influenced the performance of adhesives, which may be improved with an additional silane application.