title: Effect of thermocycling on the bond strength between dual-cured resin cements and zirconium-oxide ceramics.
abstract: The present study evaluated the durability of bond strength between zirconia and 3 different resin cements. Thirty stabilized tetragonal zirconium-dioxide blocks were duplicated in dual-curing resin core build-up material specimens. Resin blocks were randomly luted to zirconium surfaces using 1) Clearfil Esthetic Cement (CLF), 2) RelyX Unicem Aplicap (RELX), or 3) Multilink Automix (MLA). After 24 h, half of the specimens from each of the 3 groups were loaded in tension until fracture (0.5 mm/min). The remaining half were tested after 6,000 thermal cycles (5 to 55°C). Data were analyzed using 2-way ANOVA and the Tukey test (α = 0.05). Fractographic analysis was performed using a stereomicroscope. Tensile bond strength values were significantly affected by the luting agent system employed and by thermal aging (P < 0.001). The highest tensile bond strength values in non-thermal-aged groups were observed for specimens from the RELX and CLF groups. In contrast, in the thermal-aged groups, the highest tensile bond strength values were for the MLA and RELX groups. Moreover, while thermocycling significantly affected bond strengths in the RELX and CLF groups, the mean strength of the MLA group did not significantly change after aging. There was little difference in the distribution of failure modes in any group.
authors.affiliation: Department of Restorative Dentistry, Dental Clinic, University of L'Aquila, L'Aquila, Italy. damariom@libero.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: D'Amario
authors.forename: Marco
authors.initials: M
authors.lastname: Campidoglio
authors.forename: Anna L
authors.initials: AL
authors.lastname: Morresi
authors.forename: Ludovica
authors.initials: L
authors.lastname: Luciani
authors.forename: Enrico
authors.initials: E
authors.lastname: Marchetti
authors.forename: Mario
authors.initials: M
authors.lastname: Baldi
mesh_terms: D000704:Analysis of Variance; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D006358:Hot Temperature; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry; D055116:Self-Curing of Dental Resins; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D015040:Zirconium
chemical_list: C483701:Rely X Unicem; D019279:Resin Cements; C530542:clearfil esthetic cement; C502351:multilink adhesive system; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide