The influence of fatigue load to various adhesive resin luting agents in a zirconia-reinforced lithium silicate ceramic bonded to dentin

Purpose. To examine fatigue failure load value of etch-and-rinse and self-adhesive luting systems used to bond ZLS to dentin. Moreover, this study seeks to evaluate whether the application of unfilled resin on silanated ceramic intaglio surface could improve fatigue failure load value. Methods. Vita Suprinity (VS, Vita Zahnfabrik) blocks were sectioned into cylindrical shape (5 mm in diameter and 1.5 mm in height). All VS were crystallized, and bonded surfaces were treated as followed: Heliobond (HB, Ivoclar Vivadent) application after silanization and non-application of HB. Each VS was cemented to each flat occlusal dentin surface of extracted human molar, following the adhesive luting systems: Optibond FL (FL, Kerr) with Nexus3 (NX3, Kerr), RelyXTM Unicem (UC, 3M ESPE), and Maxcem Elite (ME, Kerr). 24-hour mean fatigue failure load was determined using a staircase approach (500,000 cycles, 20Hz, initial load = 844 N, step size = 42 N). Representatives of failed specimens were evaluated by a scanning electron microscope (SEM). Results. The Behrens-Fisher T-test revealed that ZLS cemented to dentin using self-adhesive resin luting cements (UC and ME) had a statistically significant lower mean fatigue failure load value than etch-and-rinse resin luting cement (FLNX3) (alpha = 0.05). Meanwhile, the HB application groups did not achieve statistically significant difference in fatigue failure load value when compared to non-application groups (alpha = 0.05). Conclusion. Etch-and-rinse resin luting system was recommended for cementation of ZLS to dentin, regardless the use of unfilled resin on the intaglio surface of the restoration after silanization.