Bond Strength of Different Resin Cement and Ceramic Shades Bonded to Dentin

Purpose: To evaluate the microtensile bond strength (MTBS) of ceramic cemented to dentin varying the resin cement and ceramic shades.Materials and Methods: Two VITA VM7 ceramic shades (Base Dentine 0M1 and Base Dentine 5M3) were used. A spectrophotometer was used to determine the percentage translucency of ceramic (thickness: 2.5 mm). For the MTBS test, 80 molar dentin surfaces were etched and an adhesive was applied. Forty blocks (7.2 x 7.2 x 2.5 mm) of each ceramic shade were produced and the ceramic surface was etched (10% hydrofluoric acid) for 60 s, followed by the application of silane and resin cement (A3 yellow and transparent). The blocks were cemented to dentin using either A3 or transparent cement. Specimens were photoactivated for 20 s or 40 s, stored in distilled water (37 degrees C/24 h), and sectioned. Eight experimental groups were obtained (n = 10). Specimens were tested for MTSB using a universal testing machine. Data were statistically analyzed using ANOVA and Tukey's post-hoc tests (alpha <= 0.05).Results: The percentage translucency of 0M1 and 5M3 ceramics were 10.06 (+/- 0.25)% and 1.34 (+/- 0.02)%, respectively. The lowest MTBS was observed for the ceramic shade 5M3. For the 0M1 ceramic, the A3 yellow cement that was photocured for 20 s exhibited the lowest MTBS, while the transparent cement that was photocured for 40 s presented the highest MTBS.Conclusions: For the 2.5-mm-thick 5M3 ceramic restorations, the MTBS of ceramic cemented to dentin significantly increased. The dual-curing cement Variolink II photocured for 40 s is not recommended for cementing the Base Dentine 5M3 feldspathic ceramic to dentin.

Effect of Resin Cement Type on the Microtensile Bond Strength to Lithium Disilicate Ceramic and Dentin Using Different Test Assemblies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of Surface Conditioning Modalities on the Repair Bond Strength of Resin Composite to the Zirconia Core / Veneering Ceramic Complex

Purpose: This study evaluated the effect of different surface conditioning protocols on the repair strength of resin composite to the zirconia core / veneering ceramic complex, simulating the clinical chipping phenomenon.Materials and Methods: Forty disk-shaped zirconia core (Lava Zirconia, 3M ESPE) (diameter: 3 mm) specimens were veneered circumferentially with a feldspathic veneering ceramic (VM7, Vita Zahnfabrik) (thickness: 2 mm) using a split metal mold. They were then embedded in autopolymerizing acrylic with the bonding surfaces exposed. Specimens were randomly assigned to one of the following surface conditioning protocols (n = 10 per group): group 1, veneer: 4% hydrofluoric acid (HF) (Porcelain Etch) + core: aluminum trioxide (50-mu m Al2O3) + core + veneer: silane (ESPE-Sil); group 2: core: Al2O3 (50 mu m) + veneer: HF + core + veneer: silane; group 3: veneer: HF + core: 30 mu m aluminum trioxide particles coated with silica (30 mu m SiO2) + core + veneer: silane; group 4: core: 30 mu m SiO2 + veneer: HF + core + veneer: silane. Core and veneer ceramic were conditioned individually but no attempt was made to avoid cross contamination of conditioning, simulating the clinical intraoral repair situation. Adhesive resin (VisioBond) was applied to both the core and the veneer ceramic, and resin composite (Quadrant Posterior) was bonded onto both substrates using polyethylene molds and photopolymerized. After thermocycling (6000 cycles, 5 degrees C-55 degrees C), the specimens were subjected to shear bond testing using a universal testing machine (1 mm/min). Failure modes were identified using an optical microscope, and scanning electron microscope images were obtained. Bond strength data (MPa) were analyzed statistically using the non-parametric Kruskal-Wallis test followed by the Wilcoxon rank-sum test and the Bonferroni Holm correction (alpha = 0.05).Results: Group 3 demonstrated significantly higher values (MPa) (8.6 +/- 2.7) than those of the other groups (3.2 +/- 3.1, 3.2 +/- 3, and 3.1 +/- 3.5 for groups 1, 2, and 4, respectively) (p < 0.001). All groups showed exclusively adhesive failure between the repair resin and the core zirconia. The incidence of cohesive failure in the ceramic was highest in group 3 (8 out of 10) compared to the other groups (0/10, 2/10, and 2/10, in groups 1, 2, and 4, respectively). SEM images showed that air abrasion on the zirconia core only also impinged on the veneering ceramic where the etching pattern was affected.Conclusion: Etching the veneer ceramic with HF gel and silica coating of the zirconia core followed by silanization of both substrates could be advised for the repair of the zirconia core / veneering ceramic complex.

Effect of the Etching Duration and Ultrasonic Cleaning on Microtensile Bond Strength Between Feldspathic Ceramic and Resin Cement

This study assessed the effect of different etching durations of feldspathic ceramic with hydrofluoric acid (HF) and ultrasonic cleaning of the etched ceramic surface on the microtensile bond strength stability of resin to a feldspathic ceramic. The research hypotheses investigated were: (1) different etching times would not affect the adhesion resistance and (2) ultrasonic cleaning would improve the adhesion. Ceramic blocks (6 x 6 x 5 mm) (N = 48) were obtained. The cementations surfaces were duplicated in resin composite. The six study groups (n = 8) were: G1Etching with 10% aqueous HF (30 s) + silane; G 210% HF (1 min) + silane; G3-10% HF (2 min) + silane; G4-10% HF (30 s) + ultrasonic cleaning (4 min) in distilled water + silane; G5-10% HF (1 min) + ultrasonic cleaning + silane; G6-10% HF (2 min) ultrasonic cleaning + silane. The cemented blocks were sectioned into microbars for the microtensile test. The etching duration did not create significant difference among the groups (p = .156) but significant influence of ultrasonic cleaning was observed (p = .001) (Two-way ANOVA and Tukey's test, p > 0.05). All the groups after ultrasonic cleaning presented higher bond strength (19.38-20.08 MPa) when compared with the groups without ultrasonic cleaning (16.2117.75 MPa). The bond strength between feldspathic ceramic and resin cement was not affected by different etching durations using HF. Ultrasonic cleaning increased the bond strength between ceramic surface and resin cement, regardless of the etching duration.

The potential of novel primers and universal adhesives to bond to zirconia

Objectives: To investigate the adhesive potential of novel zirconia primers and universal adhesives to surface-treated zirconia substrates.Methods: Zirconia bars were manufactured (3.0 mm x 3.0 mm x 9.0 mm) and treated as follows: no treatment (C); air abrasion with 35 mu m alumina particles (S); air abrasion with 30 mu m silica particles using one of two systems (Rocatec or SilJet) and; glazing (G). Groups C and S were subsequentially treated with one of the following primers or adhesives: ZP (Z-Prime Plus), AZ (AZ Primer); MP (Monobond Plus); SU (ScotchBond Universal) and; EA (an Experimental Adhesive). Groups Rocatec and SilJet were silanized prior to cementation. Samples form group G were further etched and silanized. Bars were cemented (Multilink) onto bars of a silicate-based ceramic (3.0 mm x 3.0 mm x 9.0 mm) at 90 degrees angle, thermocycled (2.500 cycles, 5-55 degrees C, 30 s dwell time), and tested in tensile strength test. Failure analysis was performed on fractured specimens to measure the bonding area and crack origin.Results: Specimens from group C did not survive thermocycling, while CMP, CSU and CEA groups survived thermocycling but rendered low values of bond strength. All primers presented a better bond performance after air abrasion with Al2O3 particles. SilJet was similar to Rocatec, both presenting the best bond strength results, along with SMP, SSU and CEA. G promoted intermediate bond strength values. Failure mode was predominately adhesive on zirconia surface combined to cohesive of the luting agent.Conclusions: Universal adhesives (MP, SU, EA) may be a considerable alternative for bonding to zirconia, but air abrasion is still previously required. Air abrasion with silica particles followed by silane application also presented high bond strength values. (C) 2013 Elsevier Ltd. All rights reserved.

Zirconia-Porcelain Bonding: Effect of Multiple Firings on Microtensile Bond Strength

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Nd:YAG Laser on the Bond Strength of Self-etching and Conventional Adhesive Systems to Dental Hard Tissues

Purpose: The aim of this study was to investigate the influence of Nd:YAG laser on the shear bond strength to enamel and dentin of total and self-etch adhesives when the laser was applied over the adhesives, before they were photopolymerized, in an attempt to create a new bonding layer by dentin-adhesive melting.Material and Methods: One-hundred twenty bovine incisors were ground to obtain flat surfaces. Specimens were divided into two substrate groups (n=60): substrate E (enamel) and substrate D (dentin). Each substrate group was subdivided into four groups (n=15), according to the surface treatment accomplished: X (Xeno III self-etching adhesive, control), XL (Xeno III + laser Nd:YAG irradiation at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental), S (acid etching + Single Bond conventional adhesive, Control), and SL (acid etching + Single Bond + laser Nd:YAG at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental). The bonding area was delimited with 3-mm-diameter adhesive tape for the bonding procedures. Cylinders of composite were fabricated on the bonding area using a Teflon matrix. The teeth were stored in water at 37 degrees C/48 h and submitted to shear testing at a crosshead speed of 0.5 mm/min in a universal testing machine. Results were analyzed with three-way analysis of variance (ANOVA; substrate, adhesive, and treatment) and Tukey tests (alpha=0.05). ANOVA revealed significant differences for the substrate, adhesive system, and type of treatment: lased or unlased (p<0.05). The mean shear bond strength values (MPa) for the enamel groups were X=20.2 +/- 5.61, XL=23.6 +/- 4.92, S=20.8 +/- 4.55, SL=22.1 +/- 5.14 and for the dentin groups were X=14.1 +/- 7.51, XL=22.2 +/- 6.45, S=11.2 +/- 5.77, SL=15.9 +/- 3.61. For dentin, Xeno III self-etch adhesive showed significantly higher shear bond strength compared with Single Bond total-etch adhesive; Nd:YAG laser irradiation showed significantly higher shear bond strength compared with control (unlased).Conclusion: Nd:YAG laser application prior to photopolymerization of adhesive systems significantly increased the bond strength to dentin.

Influence of Different Surface Treatments on Bond Strength of Resin Composite Using the Intrinsic Characterization Technique

Objective: This study evaluated the influence of different surface treatments on the resin bond strength/light-cured characterizing materials (LCCMs), using the intrinsic characterization technique. The intrinsic technique is characterized by the use of LCCMs between the increments of resin composite (resin/thin film of LCCM/external layer of resin covering the LCCM).Materials and Methods: Using a silicone matrix, 240 blocks of composite (Z350/3M ESPE) were fabricated. The surfaces received different surface treatments, totaling four groups (n=60): Group C (control group), no surface treatment was used; Group PA, 37% phosphoric acid for one minute and washing the surface for two minutes; Group RD, roughening with diamond tip; and Group AO, aluminum oxide. Each group was divided into four subgroups (n=15), according to the LCCMs used: Subgroup WT, White Tetric Color pigment (Ivoclar/Vivadent) LCCM; Subgroup BT, Black Tetric Color pigment (Ivoclar/Vivadent) LCCM; Subgroup WK, White Kolor Plus pigment (Kerr) LCCM; Subgroup BK, Brown Kolor Plus pigment (Kerr) LCCM. All materials were used according to the manufacturer's instructions. After this, block composites were fabricated over the LCCMs. Specimens were sectioned and submitted to microtensile testing to evaluate the bond strength at the interface. Data were submitted to two-way analysis of variance (ANOVA) (surface treatment and LCCMs) and Tukey tests.Results: ANOVA presented a value of p<0.05. The mean values (+/- SD) for the factor surface treatment were as follows: Group C, 30.05 MPa (+/- 5.88)a; Group PA, 23.46 MPa (+/- 5.45)b; Group RD, 21.39 MPa (+/- 6.36)b; Group AO, 15.05 MPa (+/- 4.57)c. Groups followed by the same letters do not present significant statistical differences. The control group presented significantly higher bond strength values than the other groups. The group that received surface treatment with aluminum oxide presented significantly lower bond strength values than the other groups.Conclusion: Surface treatments of composite with phosphoric acid, diamond tip, and aluminum oxide significantly diminished the bond strength between composite and the LCCMs.

Effect of Dental Surface Treatment with Nd:YAG and Er:YAG Lasers on Bond Strength to Recently Bleached Dentin

The objective of this study was to evaluate the effect of surface treatment with Er:YAG and Nd:YAG lasers on resin composite bond strength to recently bleached dentin. A total of 120 bovine incisors were distributed into two groups: C- without bleaching; and B- bleached with 35% hydrogen peroxide. Each group was divided into three subgroups: N- without laser treatment; Nd- Nd:YAG laser irradiation; and Er- Er:YAG laser irradiation. The adhesive system (Adper Single Bond 2) was applied and composite build-ups were constructed with Filtek Supreme (3M/ESPE). The teeth were sectioned to obtain dentin-resin sticks (1x1mm(2)) and tested by microtensile bond testing. The bond strength values in group B, subgroup N (16.1 +/- 3.5MPa) presented no significant difference compared with group B, subgroup Er (14.7 +/- 6.1MPa). Group C, subgroup N (26.8 +/- 7.4MPa) presented no significant difference compared with group B, subgroup Nd (28.8 +/- 5.6MPa). Group C, subgroup Nd (36.1 +/- 7.9MPa) presented a significant increase in bond strength compared with the other groups. The Er:YAG laser did not influence the bond strength of bleached specimens, and the use of the Nd:YAG laser on bleached specimens was able to reverse the immediate effects of bleaching, obtaining bond strength values similar to those of the control group.

Dentin Bond Strength: Influence of Er:YAG and Nd:YAG Lasers

The aim of this study was to investigate the effects of Er:YAG and Nd:YAG lasers on the shear bond strength of composite resin to dentin. The coronal portion of 56 human molars was divided into three parts, and the dentin thickness was standardized at 2 mm. A 3-mm hole was marked in the center of each tooth with sealing tape paper. The specimens (n = 14) were then divided into four groups: (1) acid etching + Single Bond (SB) (control), (2) acid etching + SB + Nd: YAG laser irradiation (before adhesive curing), (3) thermal etching with the Er: YAG laser + SB, and (4) thermal etching with the Er: YAG laser + SB + Nd: YAG laser irradiation (before adhesive curing). A composite resin cylinder was built into the delimited area for conducting the shear bond strength test on the universal testing machine. The means +/- standard deviations were: group 1, 17.05 +/- 4.15 MPa; group 2, 16.90 +/- 3.36 MPa; group 3, 12.12 +/- 3.85 MPa; and group 4, 12.92 +/- 2.73 MPa. Groups 1 and 2 presented significantly higher values than groups 3 and 4. It was concluded that conventional etching with 37% phosphoric acid yielded significantly higher bond strength values compared to thermal etching with the Er:YAG laser. The Nd:YAG laser did not significantly influence the bond strength.

Effect of surface treatment on the bond strength between yttria partially stabilized zirconia ceramics and resin cement

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Does the Method of Caries Induction Influence the Bond Strength to Dentin of Primary Teeth?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Performance of a New One-step Multi-mode Adhesive on Etched vs Non-etched Enamel on Bond Strength and Interfacial Morphology

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of reducing acid etching time on bond strength to noncarious and caries-affected primary and permanent dentin

The purpose was to evaluate the effect of acid etching time on the bond strength of a simplified etch-and-rinse adhesive system to noncarious and caries-affected dentin of primary and permanent teeth. Methods: Twenty-four extracted primary and permanent teeth were divided into three groups, according to the acid etching time. Four teeth from each group were exposed to a microbiological caries-inducing protocol. After caries removal, noncarious and caries-affected dentin surfaces were etched with 37 percent phosphoric acid for five, 10, or 15 seconds prior to the application of Prime & Bond NT adhesive. Crowns were restored with resin composite and prepared for microtensile testing. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (á=0.05). Results: Higher bond strengths were obtained for noncarious dentin vs. cariesaffected dentin for both primary and permanent teeth. Reducing the acid etching time from 15 to five seconds did not affect the bond strength to caries-affected or noncarious dentin in primary teeth. For permanent teeth, lower bond strength values were observed when the noncarious dentin was etched for five seconds, while no difference was seen between 10 and 15 seconds. Conclusions: For Prime & Bond NT, the etching of dentin for five seconds could be recommended for primary teeth, while 10 seconds would be the minimum time for permanent teeth.

Air abrasion before and/or after zirconia sintering: surface characterization, flexural strength, and resin cement bond strength

The purpose of this in vitro study was to evaluate the effect of air-abrasion/zirconia sintering order on the yttria partially stabilized tetragonal zirconia polycrystal (Y-TZP) surface characterization (roughness, morphology, and phase transformation), flexural strength (FS), and shear bond strength (SBS) to a resin cement. Y-TZP specimens were air abraded with 50-μm Al2O3 particles after (AS), before (BS), or before and after zirconia sintering (BAS). For roughness (Ra), 30 block specimens (12×12×3.0 mm; n=10) had their surfaces analyzed by a profilometer. Next, on the air-abraded surfaces of these specimens, composite resin discs (n=30) were bonded with RelyX ARC. The bonded specimens were stored for 24 hours in distilled water at 37°C before shear testing. Failure mode was determined with a stereomicroscope (20×). The surface morphology (n=2) was evaluated by SEM (500×). For the four-point flexural strength test (EMIC DL2000), 39 bar-shaped specimens (20×4.0×1.2 mm; n=13) were air abraded according to the three conditions proposed, and an additional group (nonabraded) was evaluated (n=13). The quantitative analysis of phase transformation (n=1) was completed with Rietveld refinement with X-ray diffraction data. Ra (μm) and SBS (MPa) data were analyzed by one-way analysis of variance (ANOVA) and the Tukey test (α=0.05). Pearson correlation analysis was used to determine if there was a correlation between roughness and SBS. For FS (MPa) data, one-way ANOVA and the Dunnett C-test (α=0.05) were used. The air-abrasion/zirconia sintering order influenced significantly (p<0.001) Ra, SBS, and FS. The BS and AS groups presented the highest (1.3 μm) and the lowest (0.7 μm) Ra. The highest SBS (7.0 MPa) was exhibited by the BAS group, followed by the AS group (5.4 MPa) and finally by the BS group (2.6 MPa). All groups presented 100% adhesive failure. A weak correlation (r=−0.45, p<0.05) was found between roughness and SBS. The air-abrasion/zirconia sintering order provided differences in the surface morphology. The nonabraded (926.8 MPa) and BS (816.3 MPa) groups exhibited statistically similar FS values but lower values than the AS (1249.1 MPa) and BAS (1181.4 MPa) groups, with no significant difference between them. The nonabraded, AS, BS, and BAS groups exhibited, respectively, percentages of monoclinic phase of 0.0 wt%, 12.2 wt%, 0.0 wt%, and 8.6 wt%. The rougher surface provided by the air-abrasion before zirconia sintering may have impaired the bonding with the resin cement. The morphological patterns were consistent with the surface roughness. Considering the short-term SBS and FS, the BAS group exhibited the best performance. Air abrasion, regardless of its performance order, provides tetragonal to monoclinic transformation, while sintering tends to zero the monoclinic phase content.