Dentin microshear bond strength of various resin luting agents to zirconia-reinforced lithium silicate ceramics

Abstract

Statement of problemThe performance of adhesive and resin luting cements used to bond zirconia-reinforced lithium silicate (ZLS) ceramics to dentin has not been well established. PurposeThe purpose of this in vitro study was to examine the microshear bond strength (μSBS) of an etch-and-rinse adhesive system, a universal adhesive, and a self-adhesive resin cement that were used to bond ZLS to dentin. Material and methodsVITA Suprinity (VS) and Celtra Duo (CD) blocks were sectioned into 36 and 72 microbars (1×1×3 mm). All VS were crystallized, while half of CD were additionally fired and defined as fired-Celtra Duo (FCD). The others were defined as unfired-Celtra Duo (UCD). Each microbar was cemented to each flat occlusal dentin surface of a human first premolar, following the adhesive luting systems: Scotchbond Multi-purpose (SM), Single Bond Universal (SU) combined with RelyX Ultimate, and RelyX Unicem (U2) (n=12 per group). μSBS at 24 hours was then determined, and the data were analyzed by using 2-way ANOVA and a Tukey post hoc test (α=.05). Failure modes were analyzed under a stereomicroscope at ×40 magnification. ResultsTwo-way ANOVA revealed that the type of ZLS had no influence on μSBS (P=.699). However, the kinds of adhesive luting cements and their interaction had a statistically significant effect on μSBS (P<.001 and P=.002). U2 had a statistically significant lower mean μSBS, regardless of the type of ZLS, than SM and SU (P≤.05), while UCDU2 did not show a statistically significant difference in μSBS from UCDSU (P=.478). ConclusionsResin cement used with an etch-and-rinse and a universal adhesive agent demonstrates higher bond strength for the cementation of zirconia-reinforced lithium silicate ceramics to dentin than a self-adhesive resin cement.