title: Ceramic primer heat-treatment effect on resin cement/Y-TZP bond strength.
abstract: The purpose of this study was to evaluate the effect of different heat-treatment strategies for a ceramic primer on the shear bond strength of a 10-methacryloyloxydecyl-dihydrogen-phosphate (MDP)-based resin cement to a yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic. Specimens measuring 4.5 × 3.5 × 4.5 mm(3) were produced from Y-TZP presintered cubes and embedded in polymethyl methacrylate (PMMA). Following finishing, the specimens were cleaned using an ultrasound device and distilled water and randomly divided into 10 experimental groups (n=14) according to the heat treatment of the ceramic primer and aging condition. The strategies used for the experimental groups were: GC (control), without primer; G20, primer application at ambient temperature (20°C); G45, primer application + heat treatment at 45°C; G79, primer application + heat treatment at 79°C; and G100, primer application + heat treatment at 100°C. The specimens from the aging groups were submitted to thermal cycling (6000 cycles, 5°C/55°C, 30 seconds per bath) after 24 hours. A cylinder of MDP-based resin cement (2.4 mm in diameter) was constructed on the ceramic surface of the specimens of each experimental group and stored for 24 hours at 37°C. The specimens were submitted to a shear bond strength test (n=14). Thermal gravimetric analysis was performed on the ceramic primer. The data obtained were statistically analyzed by two-way analysis of variance and the Tukey test (α=0.05). The experimental group G79 without aging (7.23 ± 2.87 MPa) presented a significantly higher mean than the other experimental groups without aging (GC: 2.81 ± 1.5 MPa; G20: 3.38 ± 2.21 MPa; G100: 3.96 ± 1.57 MPa), showing no difference from G45 only (G45: 6 ± 3.63 MPa). All specimens of the aging groups debonded during thermocycling and were considered to present zero bond strength for the statistical analyses. In conclusion, heat treatment of the metal/zirconia primer improved bond strength under the initial condition but did not promote stable bonding under the aging condition.
authors.affiliation: Biomaterials and Oral Biology, University of São Paulo (USP), São Paulo, Brazil.
authors.forename: L H
authors.initials: LH
authors.lastname: Silva
authors.forename: A K F
authors.initials: AK
authors.lastname: Costa
authors.forename: J R C
authors.initials: JR
authors.lastname: Queiroz
authors.forename: M A
authors.initials: MA
authors.lastname: Bottino
authors.forename: L F
authors.initials: LF
authors.lastname: Valandro
mesh_terms: D000268:Adhesiveness; D002152:Calorimetry, Differential Scanning; D002516:Ceramics / Q000737:chemistry*; D001840:Dental Bonding; D003799:Dental Stress Analysis / Q000295:instrumentation; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D008742:Methyl n-Butyl Ketone / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013818:Thermogravimetry; D013997:Time Factors; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*; D020002:tert-Butyl Alcohol / Q000737:chemistry
chemical_list: D008689:Methacrylates; C438843:Panavia-Fluoro; D019279:Resin Cements; C499362:yttria stabilized tetragonal zirconia; D015019:Yttrium; D008742:Methyl n-Butyl Ketone; C069749:methacryloyloxydecyl dihydrogen phosphate; D015040:Zirconium; D020002:tert-Butyl Alcohol; C005458:methyl isobutyl ketone