feldspar and phosphoric-acid

To evaluate the microtensile bond strength (MTBS) of ceramic cemented to dentin varying the resin cement and ceramic shades.. 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°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 (α <= 0.05).. 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.. 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.

Topics: Acid Etching, Dental; Aluminum Silicates; Cementation; Ceramics; Color; Dental Bonding; Dental Cements; Dental Porcelain; Dental Stress Analysis; Dentin; Humans; Hydrofluoric Acid; Light-Curing of Dental Adhesives; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Phosphoric Acids; Potassium Compounds; Resin Cements; Silanes; Spectrophotometry; Stress, Mechanical; Surface Properties; Temperature; Tensile Strength; Time Factors; Water

This study compared the durability of repair bond strength of a resin composite to a reinforced ceramic after three repair systems.. Alumina-reinforced feldspathic ceramic blocks (Vitadur-alpha) (N=30) were randomly divided into three groups according to the repair method: PR-Porcelain Repair Kit (Bisco) [etching with 9.5% hydrofluoric acid+silanization+adhesive]; CJ-CoJet Repair Kit (3M ESPE) [(chairside silica coating with 30microm SiO(2)+silanization (ESPE)-Sil)+adhesive (Visio-Bond)]; CL-Clearfil Repair Kit [diamond surface roughening, etching with 40% H(3)PO(4)+Clearfil Porcelain Bond Activator+Clearfil SE Bond)]. Resin composite was photo-polymerized on each conditioned ceramic block. Non-trimmed beam specimens were produced for the microtensile bond strength (microTBS) tests. In order to study the hydrolytic durability of the repair methods, the beam specimens obtained from each block were randomly assigned to two conditions. Half of the specimens were tested either immediately after beam production (Dry) or after long-term water storage (37 degrees C, 150 days) followed by thermocyling (12,000 cycles, 5-55 degrees C) in a universal testing machine (1mm/min). Failure types were analyzed under an optical microscope and SEM.. microTBS results were significantly affected by the repair method (p=0.0001) and the aging conditions (p=0.0001) (two-way ANOVA, Tukey's test). In dry testing conditions, PR method showed significantly higher (p<0.001) repair bond strength (19.8+/-3.8MPa) than those of CJ and CL (12.4+/-4.7 and 9.9+/-2.9, respectively). After long-term water storage and thermocycling, CJ revealed significantly higher results (14.5+/-3.1MPa) than those of PR (12.1+/-2.6MPa) (p<0.01) and CL (4.2+/-2.1MPa) (p<0.001). In all groups when tested in dry conditions, cohesive failure in the composite accompanied with adhesive failure at the interface (mixed failures), was frequently observed (76%, 80%, 65% for PR, CJ and CL, respectively). After aging conditions, while the specimens treated with PR and CJ presented primarily mixed failure types (52% and 87%, respectively), CL group presented mainly complete adhesive failures at the interface (70%).. Hydrolytic stability of the repair method based on silica coating and silanization was superior to the other repair strategies for the ceramic tested.

Topics: Acid Etching, Dental; Aluminum Oxide; Aluminum Silicates; Bisphenol A-Glycidyl Methacrylate; Composite Resins; Dental Bonding; Dental Cements; Dental Materials; Dental Porcelain; Dental Prosthesis Repair; Dental Restoration Failure; Dental Stress Analysis; Dentin-Bonding Agents; Diamond; Humans; Hydrofluoric Acid; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Phosphoric Acids; Potassium Compounds; Resin Cements; Silanes; Silicon Dioxide; Stress, Mechanical; Temperature; Tensile Strength; Time Factors; Water

Purpose Hydrofluoric acid has been used to remove salivary contamination in dental glass-ceramics before bonding treatment. However, alternative methods are required because hydrofluoric acid is harmful. This study examined the cleaning effects of phosphoric acid and sodium hydroxide on glass-ceramics for bonding pre-treatment.Methods Feldspar porcelain was divided into four groups: (C) cleaned porcelain without any contamination, (S) porcelain contaminated with saliva, (SPA) porcelain cleaned with 37% phosphoric acid after saliva contamination, and (SSH) porcelain cleaned with 10% sodium hydroxide after saliva contamination. Each sample was bonded to the resin cement using a silane-containing primer. They were then subjected to a shear bond strength (SBS) test. Each surface was analyzed by scanning electron microscopy (SEM), contact angle measurements, and Fourier transform infrared spectroscopy (FT-IR).Results The SBS of group SSH was comparable to that of group C but significantly higher than that of groups S and SPA. SEM observations showed that saliva-like structures remained on the samples of groups S and SPA, but not on the SSH group. The contact angles of groups C and SSH were comparable and significantly smaller than those of groups S and SPA, respectively. FT-IR analysis also revealed saliva in groups S and SPA, which was absent in the SSH group.Conclusions The saliva remained on the porcelain even after cleaning with phosphoric acid, and SBS was not restored to the same level as before the contamination. In contrast, sodium hydroxide eliminated saliva and restored SBS to the same level as before contamination.

Topics: Dental Bonding; Dental Porcelain; Dental Stress Analysis; Hydrofluoric Acid; Materials Testing; Resin Cements; Saliva; Shear Strength; Sodium Hydroxide; Spectroscopy, Fourier Transform Infrared; Surface Properties

Phosphoric acid (PA) etchants are widely used for the bonding pretreatment of teeth; however, their influences on the bonding between glass-ceramics and resin cement have not been clarified yet. This study investigated the effect of a thickening agent on the bonding strength between feldspar porcelain treated with a PA etchant and resin cement with a silane coupling agent. The experiments were performed using two PA etchants: commercial one and prepared one consisting a PA aqueous solution and poly(ethylene glycol) thickening agent. The samples were evaluated by shear bond strength testing, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The obtained results revealed that the thickening agent adhered to the porcelain surface and inhibited cement bonding. Meanwhile, PA remained on the surface due to the presence of the thickening agent and activated the silane coupling agent. Overall, the PA etchant did not improve the bond durability.

Topics: Ceramics; Dental Bonding; Dental Porcelain; Materials Testing; Resin Cements; Shear Strength; Silanes; Surface Properties

The objective of this study was to evaluate the influence of hydrofluoric acid (HF) concentration, etching time, and application of phosphoric acid (PA) followed by neutralization with sodium bicarbonate on the bond strength between a feldspar ceramic and resin cement. Thus, 80 blocks (10 x 12 x 2 mm) of glass ceramic (VM - Vita Mark II - Vita Zahnfabrik) were made and randomly assigned to eight groups (n = 10) according to the factors: HF concentration (5 and 10%), etching time (60 and 120 s), and use of phosphoric acid (PA) (with and without). According to the experimental group, 37% PA (Condac, FGM) was applied after HF etching for 60s. Afterwards, samples were immersed in sodium bicarbonate for 1 min then in an ultrasonic bath in distilled water (5 min) for cleaning. After surface bonding treatment, cylinders (Ø = 2 mm; h = 2 mm) of dual resin cement (AllCem / FGM) were made in the center of each block. The samples were then stored in water (37ºC) for 90 days and submitted to the shear bond test (50 KgF, 1 mm/min). Failure analysis was performed by stereomicroscope and scanning electron microscopy. Data (MPa) were analyzed with 3-way ANOVA and Tukey's test. Only the factor "HF concentration" was significant (p = 0.02). Most failures were of cohesive in ceramic (40%) and mixed types (42.5%). The 10% HF resulted in higher shear bond strength value than the 5% HF. Surface cleaning with phosphoric acid followed by sodium bicarbonate and HF time (60 or 120 seconds) did not influence the resin bond strength to feldspar ceramic.

Topics: Aluminum Silicates; Analysis of Variance; Dental Bonding; Dental Porcelain; Hydrofluoric Acid; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Phosphoric Acids; Potassium Compounds; Reference Values; Reproducibility of Results; Resin Cements; Shear Strength; Silanes; Surface Properties; Time Factors

To evaluate the effect of the cementation strategy and mechanical cycling (MC) on the microtensile bond strength (MTBS) of feldspathic inlays cemented to premolars.. Forty-eight human premolars were prepared and porcelain inlays were produced. Specimens were allocated into 3 groups, based on the cementation strategy: 1) conventional adhesive cementation (RelyX ARC, 3M ESPE): application of etch-and-rinse single bottle adhesive to dentin / ceramic surface treated with hydrofluoric acid (HF) and silane (S) / cementation with resin cement; 2) simplified cementation using a self-adhesive resin cement (RelyX U100, 3M ESPE); 3) modified simplified cementation using a self-adhesive resin cement (RelyX U100, 3M ESPE) with HF+S treatment. Half of the specimens from each group were submitted to MC (2x106 pulses, frequency = 4 Hz, load = 100 N). Each specimen was serially sliced for MTBS and the failures were classified. The stress distribution analysis using FEA was verified.. All of the bar-samples from G2 were lost during cutting of the specimens. Mechanical-cycling had no significant effect on bond strength, whereas cementation strategy significant affected MTBS results. The most common type of failure was cohesive of cement. FEA showed that stresses were concentrated mainly at the loading region going up to the root fixation.. Porcelain inlays cemented with conventional resin cement or self-adhesive resin cement should be associated with ceramic surface treatment. FEA showed the most critical zone for failure is located in the cement region close to the marginal crest.

Topics: Acid Etching, Dental; Adhesiveness; Aluminum Silicates; Bicuspid; Bisphenol A-Glycidyl Methacrylate; Cementation; Composite Resins; Computer-Aided Design; Dental Bonding; Dental Cavity Preparation; Dental Porcelain; Dentin; Elastic Modulus; Finite Element Analysis; Humans; Hydrofluoric Acid; Inlays; Materials Testing; Phosphoric Acids; Polyethylene Glycols; Polymethacrylic Acids; Potassium Compounds; Resin Cements; Silanes; Stress, Mechanical; Surface Properties; Tensile Strength

The aim of this in vitro study was to observe the effect of hydrofluoric acid (HF) on the surface of two glass ceramics for Cerec and to compare it with the effect on a conventional glass ceramic. Discs were cut from a feldspathic ceramic block (VitaMKII) and from a leucite reinforced glass ceramic (IPS EMPRESS CAD) for Cerec. 5% and 9% HF concentrations were used during 1 min and 2 min each. Afterwards samples were thoroughly water rinsed for 30 s. Half of the 9% HF 1 min samples were subsequently submitted to a complex post-etching cleaning. All samples were observed under a scanning electron microscope (SEM). The conventional feldspathic ceramic samples were built up on a refractory die and a platinum foil. They were treated with 9% HF for 2 min and water rinsed for 30 s. Half of the samples were submitted to the same post-etching cleaning protocol. All samples were examined under SEM and EDX. The Cerec ceramic samples and the platinum foil ones were clean and free of any precipitate after 30 s of water rinsing. Acid concentration, times of application and the postetching cleaning treatment did not influence the cleanliness of the samples. A thick layer of deposit was observed only on the refractory die samples. This was only diminished after the post-etching treatment. The EDX analysis detected the presence of fluoride (F) only on the refractory die samples.

Topics: Acid Etching, Dental; Aluminum Oxide; Aluminum Silicates; Ceramics; Composite Resins; Computer-Aided Design; Dental Cements; Dental Etching; Dental Porcelain; Fluorides; Humans; Hydrofluoric Acid; Materials Testing; Microscopy, Electron, Scanning; Phosphoric Acids; Platinum; Potassium Compounds; Resin Cements; Spectrometry, X-Ray Emission; Surface Properties; Time Factors; Ultrasonics; Water

The purpose of this in vitro study was to evaluate the effects of four surface treatments and two resin cements on the repair bond strength of a ceramic primer.. Eighty-eight pairs of disks (10 and 5 mm in diameter, 3 mm thickness) were prepared from heat-pressed feldspar ceramics (GC Initial IQ). After being stored in mucin-artificial saliva for 2 weeks, the 10-mm disks were divided into four surface treatment groups (n = 22) and then treated as follows: (1) no treatment (control); (2) 40% phosphoric acid; (3) 5% hydrofluoric acid + acid neutralizer + 40% phosphoric acid; (4) silica coating (CoJet-sand) + 40% phosphoric acid. The 5-mm disks were treated with 5% hydrofluoric acid + 40% phosphoric acid. The two sizes of porcelain disks, excluding the control group, were primed with Clearfil Ceramic Primer. The specimens in each group were further divided into two subgroups of 11 each, and bonded with Clearfil Esthetic Cement (CEC) or Panavia F 2.0 Cement (PFC). The specimens were stored in distilled water at 37°C for 24 hours, thermocycled for 3000 cycles at 5 to 55°C, and stored at 37°C for an additional 7 days. Shear bond strength (SBS) was measured with a universal testing machine at a 0.5 mm/min crosshead speed until fracture. Statistical analysis of the results was carried out with a two-way ANOVA and Tukey HSD test (α = 0.05). Debonded specimen surfaces were examined under an optical microscope to determine the mode of failure.. The statistical analysis showed that the SBS was significantly affected by surface treatment and resin cement (p < 0.05). For treatment groups bonded with CEC, the SBS (MPa) values were (1) 2.64 ± 1.1, (2) 13.31 ± 3.6, (3) 18.88 ± 2.6, (4) 14.27 ± 2.7, while for treatment groups cemented with PFC, the SBS (MPa) values were (1) 3.04 ± 1.1, (2) 16.44 ± 3.3, (3) 20.52 ± 2.2, and (4) 16.24 ± 2.9. All control specimens exhibited adhesive failures, while mixed types of failures were observed in phosphoric acid-treated groups. The other groups revealed mainly cohesive and mixed failures.. Combined surface treatment of etching with hydrofluoric acid and phosphoric acid provides the highest bond strengths to porcelain. Also, PFC exhibited higher SBS than CEC did.

Topics: Acid Etching, Dental; Aluminum Oxide; Aluminum Silicates; Dental Bonding; Dental Etching; Dental Porcelain; Dental Prosthesis Repair; Dental Stress Analysis; Humans; Hydrofluoric Acid; Materials Testing; Methacrylates; Phosphoric Acids; Potassium Compounds; Resin Cements; Saliva, Artificial; Shear Strength; Silanes; Stress, Mechanical; Surface Properties; Temperature; Time Factors; Water

To compare porcelain surfaces at debonding after use of two surface preparation methods and to evaluate a method for restoring the surface.. Lava Ceram feldspathic porcelain discs (n = 40) underwent one of two surface treatments prior to bonding orthodontic brackets. Half the discs had sandblasting, hydrofluoric acid, and silane (SB + HF + S), and the other half, phosphoric acid and silane (PA + S). Brackets were debonded using bracket removing pliers, and resin was removed with a 12-fluted carbide bur. The surface was refinished using a porcelain polishing kit, followed by diamond polishing paste. Measurements for surface roughness (Ra), gloss, and color were made before bonding (baseline), after debonding, and after each step of refinishing. Surfaces were also examined by scanning electron microscopy (SEM). Data was analyzed with 2-way ANOVA followed by Tukey HSD tests (alpha = 0.05).. The SB + HF + S bonding method increased Ra (0.160 to 1.121 microm), decreased gloss (41.3 to 3.7) and altered color (DeltaE = 4.37; P < .001). The PA + S method increased Ra (0.173 to 0.341 microm; P < .001), but the increase in Ra was significantly less than that caused by the SB + HF + S bonding method (P < . 001). The PA + S method caused insignificant changes in gloss (41.7 to 38.0) and color (DeltaE = 0.50). The measurements and SEM observations showed that changes were fully restored to baseline with refinishing.. The PA + S method caused significantly less damage to porcelain than the SB + HF + S method. The refinishing protocol fully restored the porcelain surfaces.

Topics: Acid Etching, Dental; Aluminum Silicates; Carbon; Color; Composite Resins; Dental Bonding; Dental Debonding; Dental Etching; Dental Polishing; Dental Porcelain; Diamond; Humans; Hydrofluoric Acid; Luminescence; Materials Testing; Microscopy, Electron, Scanning; Orthodontic Brackets; Phosphoric Acids; Potassium Compounds; Resin Cements; Silanes; Surface Properties; Temperature; Time Factors; Water

To evaluate the effects of the elapsed time (ET) after nonvital bleaching (NVB) and sodium ascorbate application (10%) (SAA) on the shear bond strength of dentin to ceramic.. Bovine incisors were selected, internally bleached (35% carbamide peroxide) for 9 days and submitted to the following treatments (n = 10): G1, G2, G3-luting after 1, 7, and 14 days; G4, G5, and G6-luting after SAA, 1, 7, and 14 days, respectively. G7 and G8 were not bleached: G7-luting 24 hours after access cavity sealing; G8-luting 24 hours after access cavity sealing after SAA. After NVB, the vestibular dentin was exposed and flattened. The SAA was applied to the dentin (G4, G5, G6, G8) for 10 minutes, and it was then washed and dried. The dentin was etched (37% phosphoric acid), and an adhesive system (Single Bond 2) was applied. Feldspathic ceramic discs (VM7; 4-mm diameter, 3-mm thick) were luted with a dual-resin agent (RelyX ARC, 3M ESPE Dental Products, St. Paul, MN). After 24 hours, specimens were submitted to shear test on a universal testing machine. The data (MPa) were submitted to ANOVA and Dunnet's test (5%).. The means (+/- SD) obtained were (MPa): G1 (14 +/- 4.5), G2 (14.6 +/- 3.1), G3 (14 +/- 3.7), G4 (15.5 +/- 4.6), G5 (19.87 +/- 4.5), G6 (16.5 +/- 3.7), G7 (22.8 +/- 6.2), and G8 (18.9 +/- 5.4). SAA had a significant effect on bond strength (p= 0.0054). The effect of ET was not significant (p= 0.1519). G5 and G6 presented higher values than the other bleached groups (p < 0.05) and similar to G7 and G8 (p > 0.05).. After NVB, adhesive luting to dentin is recommended after 7 days if sodium ascorbate has been applied prior to dentin hybridization.

Topics: Acid Etching, Dental; Adhesiveness; Aluminum Silicates; Animals; Antioxidants; Ascorbic Acid; Bisphenol A-Glycidyl Methacrylate; Carbamide Peroxide; Cattle; Cementation; Dental Bonding; Dental Cements; Dental Porcelain; Dental Pulp Cavity; Dentin; Dentin-Bonding Agents; Hydrofluoric Acid; Materials Testing; Oxidants; Peroxides; Phosphoric Acids; Polyethylene Glycols; Polymethacrylic Acids; Potassium Compounds; Random Allocation; Resin Cements; Shear Strength; Stress, Mechanical; Time Factors; Tooth Bleaching; Tooth, Nonvital; Urea

To test the hypothesis that the there is no difference between the shear bond strengths of different base designs of ceramic brackets bonded to glazed feldspathic porcelains.. Forty glazed feldspathic porcelain specimens (15 mm in diameter and 1.5 mm in thickness) were prepared and divided into 4 groups (n = 10). Ten pieces of each group of different ceramic bracket base designs (beads, large round pits, and irregular base) and one group of stainless steel brackets (served as a control) were bonded to glazed feldspathic porcelains under a 200 gram load. Then all samples were subjected to shear bond strength evaluation with a universal testing machine at a crosshead speed of 0.2 mm/min. Data were analyzed through one-way ANOVA and Tukey's HSD test at a .05 significance level. The mode of failure after debonding was examined under a stereoscope.. This study revealed that the beads base design had the greatest shear bond strength (24.7 +/- 1.9 MPa) and was significantly different from the large round pits base (21.3 +/- 2 MPa), irregular base (19.2 +/- 2.0 MPa), and metal mesh base (15.2 +/- 2.4 MPa). The beads base design had 100% porcelain-adhesive failure, the large round pits had 100% bracket-adhesive failure, and the irregular base design had 70% combination failure and 30% porcelain-adhesive failure.. The hypothesis is rejected. The various base designs of metal and ceramic brackets influence bond strength to glazed feldspathic porcelain, but all should be clinically acceptable.

Topics: Acid Etching, Dental; Aluminum Silicates; Ceramics; Dental Alloys; Dental Bonding; Dental Materials; Dental Porcelain; Dental Stress Analysis; Humans; Humidity; Materials Testing; Orthodontic Appliance Design; Orthodontic Brackets; Phosphoric Acids; Potassium Compounds; Resin Cements; Shear Strength; Stainless Steel; Stress, Mechanical; Surface Properties; Temperature; Time Factors

To investigate the effect of different adhesives on the shear bond strength between a feldspathic machinable ceramic and a luting resin.. Seven groups of 20 ceramic specimens each were machined from Vita Mark II blocs. Their surfaces were uniformly treated with 1000-grit paper. Group 1 (control) was hydrofluoric-acid etched for 60 s, group 2 abraded with CoJet, and group 3 PyrosilPen-treated and silanized. Groups 4 and 5 were hydrofluoric-acid etched for 60 s and silanized with two experimental silanes. Variolink II was used as the luting resin for groups 1 to 5. Group 6 and 7 were phosphoric-acid etched for 15 s. Then group 6 was treated with Nexus and group 7 with the Panavia F 2.0 system. All specimens were stored dry for 24 h at 37 degrees C. Shear bond strength was measured prior to and after 5000 thermocycles (TC) between 5 degrees C and 55 degrees C in water. ANOVA was performed with p < or = 0.05.. Shear bond strength values 24 h / TC in MPa (SD) were as follows: group 1: 11 (3.0)/ 12 (5.3), group 2: 22 (3.9) / 25 (7.3), group 3: 26 (9.0) / 30 (8.0), group 4: 12 (5.9) / 8 (2.0), group 5: 8 (2.4) / 7 (3.4), group 6: 16 (6.1) / 3 (1.6) and group 7: 16 (8.6) / 16 (4.3). Cojet (24 h, p < or = 0.0007 / TC, p < or = 0.0001) and PyrosilPen (24 h, p < or = 0.0001/ TC, p < or = 0.0001) showed significantly higher bond strength than the control but did not differ significantly from each other. No significant differences between the control and groups 4, 5, 6, and 7 were found. PyrosilPen (p < or = 0.0001) significantly performed best prior to and after TC. Bond strength of experimental silane A (p < or = 0.0499) and Nexus (p < or = 0.0002) significantly decreased after TC.. Silicoating technology and tribochemistry are fast, trouble-free, and effective surface treatment methods for achieving very good bond strength between feldspathic ceramics and luting resins. Etching with H2F2 can thus be avoided.

Topics: Acid Etching, Dental; Aluminum Silicates; Dental Bonding; Dental Cements; Dental Etching; Dental Porcelain; Humans; Hydrofluoric Acid; Materials Testing; Phosphoric Acids; Potassium Compounds; Resin Cements; Shear Strength; Silanes; Stress, Mechanical; Surface Properties; Temperature; Time Factors