In vitro shear bond strength between fluorinated zirconia ceramic and resin cements

PURPOSE: The purpose of this study was to evaluate the efficiency of a gas-phase fluorination method under different fluorination periods through using two resin cements. MATERIALS AND METHODS: 84 zirconia specimens in dimensions of 5 mm × 5 mm × 2 mm were prepared and surface treated with 50 µm aluminum oxide particles or gas phase fluorination for 2 min, 5 min, or 10 min. One specimen in each group was surface analyzed under scanning electron microscope. The remaining specimens were bonded to composite cylinders in dimensions of 2 mm diameter and 3 mm high with Panavia SA Plus or Variolink N. Then, the specimens were stored in 37℃ distilled water for 24 hours and shear bond strength test was applied at a speed of 1 mm/min. RESULTS: The highest shear bond strength values were observed in the samples fluorinated for 5 minutes and cemented with Panavia SA Plus. Variolink N did not elicit any statistical differences between surface treatments. Panavia SA Plus resin cement and Variolink N resin cements featured statistically significant difference in shear bond strength values only in the case of 5 minutes of fluorination treatment. CONCLUSION: According to the results of this study, application of 5 minutes of fluorination with 10-methacryloyloxydecyl dihydrogen phosphate monomer (MDP) containing Panavia SA Plus resin cement increased the resin bond strength of zirconia. Fluorination of the zirconia surface using conventional resin cement, Variolink N, did not lead to an increase in bond strength.

Establishment and mechanisms of chemical interaction between phosphate monomer and zirconia model / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To analyze chemical mechanism of bonding improvement of zirconia via 10-methacryloyloxydecyl dihydrogen phosphate (MDP) conditioning.</p><p><b>METHODS</b>Various models were created for tetragonal zirconia crystals, molecular MDP, and MDP complex, and tetragonal zirconia crystal. Thermodynamic methods were used to analyze configuration between MDP and tetragonal zirconia crystal through calculation of their Gibbs free energy values and equilibrium constants.</p><p><b>RESULTS</b>Two potential configurations (double- and single-coordinate) may occur between MDP and ZrO2 crystal clusters. Thermodynamic calculations showed that -147.761 and -158.073 kJ·mol⁻¹ Gibbs free energy were required to form single- and double-coordinate configurations; their negative signs indicate that reactions for both configurations can occur. Equilibrium constant for single-coordinate configuration was 7.72×10²⁵, which was less than that of double-coordinate configuration (4.95×10²⁷), suggesting that the latter was more stable.</p><p><b>CONCLUSIONS</b>MDP can spontaneously establish a double-coordinate configuration with zirconia.
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Shear bond strength of Universal bonding systems to Ni-Cr alloy / 대한치과보철학회지

PURPOSE: The aim of this study was to evaluate the shear bond strength between Ni-Cr alloy and composite resin using universal adhesive systems coMPared to conventional method using metal primers. MATERIALS AND METHODS: For this study, a total of 120 cast commercial Ni-Cr alloy (Vera Bond 2V) disks were embedded in acrylic resin, and their surfaces were smoothed with silicon carbide papers and airborne-particle abrasion. Specimens of each metal were divided into 6 groups based on the combination of metal primers (Metal primer II, Alloy primer, Metal & Zirconia primer, MKZ primer) and universal adhesive systems (Single Bond Universal, All Bond Universal). All specimens were stored in distilled water at 37degrees C for 24 hours. Shear bond strength testing was performed with a universal testing machine at a cross head speed of 1 m/min. Data (MPa) were analyzed using one-way ANOVA and the post hoc Tukey's multiple comparison test (alpha=.05). RESULTS: There were significant differences between Single Bond Universal, All Bond Universal, Metal Primer II and Alloy Primer, MKZ Primer, Metal & Zirconia Primer (P<.001). CONCLUSION: Universal Adhesive system groups indicated high shear bond strength value bonded to Ni-Cr alloy than that of conventional system groups using primers except Metal Primer II. Within the limitations of this study, improvement of universal adhesive systems which can be applied to all types of restorations is recommended especially non-precious metal alloy. More research is needed to evaluate the effect of silane inclusion or exclusion in universal adhesive systems.

Evaluation of shear-bond strength between different self-adhesive resin cements with phosphate monomer and zirconia ceramic before and after thermocycling / 대한치과보철학회지

PURPOSE: This study compared shear bond strengths of five self-adhesive cements with phosphate monomer to zirconium oxide ceramic with and without airborn particle abrasion. MATERIALS AND METHODS: One hundred zirconia samples were air-abraded (50 microm Al2O3). One hundred composite resin cylinders were fabricated. Composite cylinders were bonded to the zirconia samples with either Permacem 2.0 (P), Clearfil(TM) SA Luting (C), Multilink(R) Speed (M), RelyX(TM) U200 Automix (R), G-Cem LinkAce(TM) (G). All bonded specimens were stored in distilled water (37degrees C) for 24 h and half of them were additionally aged by thermocycling (5degrees C, 55degrees C, 5,000 times). The bonded specimens were loaded in shear force until fracture (1 mm/min) by using Universal Testing Machine (Model 4201, Instron Co, Canton, MA, USA). The failure sites were inspected under field-emission scanning electron microscopy. The data was analyzed with ANOVA, Tukey HSD post-hoc test and paired samples t-test (alpha=.05). RESULTS: Before and after thermocycling, Multilink(R) Speed (M) revealed higher shear-bond strength than the other cements. G-Cem LinkAce(TM) (G) showed significantly lower bond strengths after thermocycling than before treatment (P.05). CONCLUSION: Most self-adhesive cements with phosphate monomer showed high shear bond strength with zirconia ceramic and weren't influenced by thermocycling, so they seem to valuable to zirconia ceramic bonding.

Effect of universal primer on shear bond strength between resin cement and restorative materials / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the difference in shear bonding strength between resin cements to dental materials when a universal primer (Monobond plus) was applied in place of a conventional primer. MATERIALS AND METHODS: Four groups of testing materials: gold alloy (Argedent Euro, n = 16), non precious metal (T-4, n = 20), zirconia (Cercon, n = 20) and glass ceramic (IPS e.max press, n = 20), were fabricated into discs, which were embedded in an acrylic resin matrix. The gold alloy specimens were airborne-particle abraded, 8 of the specimens were coated with Metal primer II, while the remaining 8 specimens were coated with Monobond plus. The non precious and zirconia specimen were airborne-particle abraded then, the control group received Alloy primer coating, while the other was coated with Monobond plus. Glass ceramic specimens were etched. 10 specimens were coated with Monobond-S and the remaining specimens were coated using Monobond plus. On top of the surface, Multilink N was polymerized in a disc shape. All of the specimens were thermal cycled before the shear bonding strength was measured. Statistical analysis was done with Two sample t-test or Mann-Whitney U test (alpha=.05). RESULTS: There were no significant differences in bonding strength depending on the type of primer used in the gold alloy and glass ceramic groups (P>.05), however, the bonding strengths of resin cements to non precious metal and zirconia groups, were significantly higher when the alloy primer was used (P<.05). CONCLUSION: Within the limitations of this study, improvement of universal primers which can be applied to all types of restorations is recommended to precious metals and zirconia ceramics. But, the bond strengths of non precious metals and zirconia ceramics were significantly lower when compared to a 10-MDP primer. More research is needed to apply universal primers to all types of restorations.