Tolga Külünk

The Effect of Laser Treatment on Bonding Between Zirconia Ceramic Surface and Resin Cement

Abstract Objective. The purpose of this in-vitro study was to evaluate and compare the effects of different surface treatments and laser irradiation on the shear bond strength of resin cement to zirconia-based ceramic. Material and methods. Forty zirconia core specimens (10-mm diameter, 2-mm thickness) were produced and embedded in the centers of autopolymerizing acrylic resin blocks. Subsequently, specimens were randomly divided into four groups, each containing 10 specimens, for different surface treatment methods. The details of the groups are as follows: Group C, no treatment applied (control); Group SB, bonding surfaces of ceramic disks were airborne particle-abraded with 110-μm alumina oxide particles; Group HF, bonding surfaces of ceramic disks were etched with 9.6% hydrofluoric acid; and Group L, bonding surfaces of ceramic disks were irradiated by a CO2 laser. A total of 40 composite resin disks were fabricated and cemented with an adhesive resin cement to the specimen surfaces. A universal test machine was used for the shear bond strength test at a crosshead speed of 1 mm/min. Results. The highest shear bond strength values were obtained with Group L (20.99 ± 3.77 MPa) and the lowest values with Group C (13.39 ± 3.10 MPa). Although there was no significant difference between Groups C, HF and SB (P > 0.05), Group L showed a significant difference from all other groups (p < 0.05). Conclusion. All surface treatment methods improved the bond strength between resin cement and the zirconium oxide ceramic surface. CO2 laser etching may represent an effective method for conditioning zirconia surfaces, enhancing micromechanical retention and improving the bond strength of resin cement on zirconia ceramic.

Determination of Resin Bond Strength to Zirconia Ceramic Surface Using Different Primers

Abstract Objective. To evaluate the effect of different primers on the bond strength of adhesive resin cement to zirconia ceramic surface in vitro. Material and methods. Thirty zirconia disk-shaped ceramic specimens (10×2 mm2) were divided into three equal groups for the application of different primers: Monobons-S, Clearfil Ceramic Primer and Signum Zirconia Bond. A further 10 specimens served as a control group. Forty composite resin blocks (6×2 mm2) were cemented (Panavia F 2.0) to zirconia ceramic specimens. Shear bond strengths were measured. Treated zirconia ceramic surfaces were examined using scanning electron microscopy. Results. One-way ANOVA showed that the application of different primers affected the shear bond strength of adhesive resin cement to zirconia ceramic. The highest test values were obtained with application of Signum Zirconia Bond, and the lowest values were obtained in the control group. Conclusion. Signum Zirconia Bond is effective for increasing the bond strength of adhesive resin cement to zirconia ceramic.

Effects of surface-conditioning methods on shear bond strength of brackets bonded to different all-ceramic materials

The aims of this study were to investigate the effects of two surface-conditioning methods on the shear bond strength (SBS) of metal brackets bonded to three different all-ceramic materials, and to evaluate the mode of failure after debonding. Twenty feldspathic, 20 fluoro-apatite, and 20 leucite-reinforced ceramic specimens were examined following two surface-conditioning methods: air-particle abrasion (APA) with 25 μm Al(2)O(3) and silica coating with 30 μm Al(2)O(3) particles modified by silica. After silane application, metal brackets were bonded with light cure composite and then stored in distilled water for 1 week and thermocycled (×1000 at 5-55°C for 30 seconds). The SBS of the brackets was measured on a universal testing machine. The ceramic surfaces were examined with a stereomicroscope to determine the amount of composite resin remaining using the adhesive remnant index. Two-way analysis of variance, Tukeys multiple comparison test, and Weibull analysis were used for evaluation of SBS. The lowest SBS was with APA for the fluoro-apatite ceramic (11.82 MPa), which was not significantly different from APA for the feldspathic ceramic (13.58 MPa). The SBS for the fluoro-apatite ceramic was significantly lower than that of leucite-reinforced ceramic with APA (14.82 MPa). The highest SBS value was obtained with silica coating of the leucite-reinforced ceramic (24.17 MPa), but this was not significantly different from the SBS for feldspathic and fluoro-apatite ceramic (23.51 and 22.18 MPa, respectively). The SBS values with silica coating showed significant differences from those of APA. For all samples, the adhesive failures were between the ceramic and composite resin. No ceramic fractures or cracks were observed. Chairside tribochemical silica coating significantly increased the mean bond strength values.

Effect of air abrasion particles on the bond strength of adhesive resin cement to zirconia core

Abstract Objective. To evaluate the effect of air abrasion with different particles of different sizes and forms on the shear bond strength of adhesive resin cement to zirconia core. Material and methods. Sixty zirconia core disks were produced and sintered. The specimens were divided into six equal groups for application of air abrasion procedures. The surfaces of the specimens were treated with one of five air abrasion particles: 30 μm silica-coated aluminum oxide particles; 1–3 μm synthetic diamond particles; 110 μm aluminum oxide particles; 30–50 μm synthetic diamond particles; and 60–80 μm cubic boron nitride particles. The remaining 10 specimens were untreated and served as controls. Composite resin disks were cemented to each of the zirconia core specimens. All specimens were stored in distilled water at 37°C for 24 h and thermocycled for 6000 cycles. The shear bond strength was measured using a universal testing machine at a crosshead speed of 1 mm/min. Data were statistically analyzed by one-way ANOVA with Tamhane tests (α = 0.05). The effect of the air abrasion procedures was examined using scanning electron microscopy. Results. Air abrasion with different materials affected the bond strength (P < 0.001). The highest bond strengths were obtained by air abrasion with 30–50 μm synthetic diamond particles; the lowest bond strengths were obtained in the control group (P < 0.001). Conclusion. Air abrasion with 30–50 μm synthetic diamond particles, 60–80 μm cubic boron nitride particles and 110 μm aluminum oxide particles showed higher bond strength values than other methods.

Effects of different surface pre-treatments on the bond strength of adhesive resin cement to quartz fiber post

Abstract Objective. The purpose of this study was to evaluate the effect of mechanical and chemical surface treatment methods on the bond strength of resin cement to fiber post. Materials and methods. The roots of 36 maxillary central incisor teeth were mounted in auto polymerized acrylic resin blocks (10 × 15 mm) and the root canals were enlarged with the drills of post system (2.1 mm width, 12 mm length). Thirty-six fiber posts were randomly assigned to one of the following surface conditioning methods: silane coupling agent, methylene chloride etching, 24% hydrogen peroxide etching, air abrasion with 50 µm Al2O3, 1–3 µm synthetic diamond particles and silica coating with 30 µm SiOx. Fiber posts were cemented to the root canals with adhesive resin cement (Panavia F 2.0). Three slices of 1.5 mm thick were obtained from each root. Push-out tests were performed with a universal testing machine. The data were analyzed with one-way analysis of variance (ANOVA) and Tukey HSD tests (α = 0.05). The effect of the surface treatments were examined under a scanning electron microscope (SEM) and surface roughness were evaluated with a profilometer. Results. Surface pre-treatment methods affected the bond strength (p < 0.05). The highest bond strengths were obtained by air abrasion with synthetic diamond particles, the lowest bond strength were obtained by etching with methylene chloride (p < 0.05). Conclusion. Mechanical surface pre-treatment methods showed higher bond strength values than chemical methods. Synthetic diamond particles may be an alternative method to increase resin cement bonding on the quartz fiber post surfaces.

The effects of different desensitizing agents on the shear bond strength of adhesive resin cement to dentin.

STATEMENT OF THE PROBLEM   The choice of desensitizing agent can affect the bond strength of adhesive resin cement to dentin. PURPOSE   The purpose of this study was to evaluate the effects of different dentin desensitizing agents on the bond strength of adhesive resin cement to dentin. MATERIALS AND METHODS   Sixty specimen teeth were randomly divided into six groups (n=10). Five groups of teeth were treated with a desensitizing agent containing sodium and calcium fluoride in cellulose alone, hydroxyethyl methacrylate (HEMA), benzalkonium chloride and sodium fluoride, HEMA and glutaraldehyde, an ormocer-based or a resin-based dentin desensitizer. The remaining 10 specimens served as controls. Adhesive resin cement was applied to the dentin surface. The shear bond strength was measured using a universal testing machine at a 0.5 mm/minute crosshead speed. The data were analyzed statistically with one-way analysis of variance and a Tukeys Honestly Significant Difference (HSD) test (α=0.05). In addition, dentin surfaces were examined by a scanning electron microscope. RESULTS   THE lowest bond strength was in the group treated with desensitizing agent containing sodium and calcium fluoride and the highest bond strength was from the group treated with desensitizing agent containing HEMA and sodium fluoride. CONCLUSIONS   Desensitizing agents containing sodium and calcium fluoride reduced the bond strength of adhesive resin cement. CLINICAL SIGNIFICANCE The type of desensitizer used is an important factor regarding the bond strength of adhesive resin cements to dentin.

The effect of different surface treatments on cement-retained implant-supported restorations.

The purpose of this study was to evaluate the effects of the various surface treatment methods on the retention of single crowns on implant abutments. The study included 50 single crowns that were cemented with adhesive resin cement onto the ITI solid abutments. The specimens were randomly divided into 5 groups, each including 10 specimens according to the following surface treatments: group C, control, abutments remained unaltered as control; group L, etching with CO(2) laser; group SB, sandblasting with 50-μm Al(2)O(3); group MS: coating with titanium nitride (TiAlN) with a radiofrequency magnetron sputtering system; and group SP, silicoating by Silano-Pen. After the surface treatment procedures were finished, the casted crowns were cemented onto the abutments, and thermocycling was applied to simulate oral environment. The uniaxial tensile force was applied to all test crowns using a universal test machine (Instron) with a crosshead speed of 0.5 mm/min. The load required to dislodge each crown was recorded in Newton. The lowest tensile bond strength values were obtained with group MS (223.26 ± 14.30 N) and significantly differ from all other groups except group C. Group SB showed highest test results (506.02 ± 18.04 N) and differs from other groups (P < .05). The test values that were obtained in group MS-group C did not show significant differences (P > .05). Sandblasting is an effective method to increase bond strength. Also, Silano-Pen and laser application is advisable for increasing the crown retention to abutments. Titanium aluminum nitride coating with magnetron sputtering technique seems to be ineffective.

The effect of alumina and aluminium nitride coating by reactive magnetron sputtering on the resin bond strength to zirconia core.

PURPOSE Although several surface treatments have been recently investigated both under in vitro and in vivo conditions, controversy still exists regarding the selection of the most appropriate zirconia surface pre-treatment. The purpose of this study was to evaluate the effect of alumina (Al) and aluminium nitride (AlN) coating on the shear bond strength of adhesive resin cement to zirconia core. MATERIALS AND METHODS Fifty zirconia core discs were divided into 5 groups; air particle abrasion with 50 µm aluminum oxide particles (Al2O3), polishing + Al coating, polishing + AlN coating, air particle abrasion with 50 µm Al2O3 + Al coating and air particle abrasion with 50 µm Al2O3 + AlN coating. Composite resin discs were cemented to each of specimens. Shear bond strength (MPa) was measured using a universal testing machine. The effects of the surface preparations on each specimen were examined with scanning electron microscope (SEM). Data were statistically analyzed by one-way ANOVA (α=.05). RESULTS The highest bond strengths were obtained by air abrasion with 50 µm Al2O3, the lowest bond strengths were obtained in polishing + Al coating group (P<.05). CONCLUSION Al and AlN coatings using the reactive magnetron sputtering technique were found to be ineffective to increase the bond strength of adhesive resin cement to zirconia core.

The Effect of Screw Color and Technique to Fill Access Hole on the Final Color of Screw-Retained Implant Crowns

The purpose of this study was to investigate the effect of screw color and thickness of the composite on the final implant color. Gray and golden-colored titanium specimens were used as 2 different backgrounds. Composite disks were made in different thicknesses. Titanium and composite disk samples were placed into a metal mold as in the test groups for color measurement. The background color did not affect the final color. Composite resin thickness affected the final color.

Surface roughness, wettability and bond strength of three different dental repair systems

Abstract The development of fibre reinforced composite materials and technologies and the improvement strength of all‐ceramics with the introduction of reinforced ceramic core materials of different compositions offer minimally invasive and increased esthetic clinical alternatives for various kinds of fixed partial restorations. Fracture of composite veneers in fibre reinforced composites or chipping of all‐ceramic restorations may cause the loss of the restoration unless a reliable intraoral repair method can be provided. The purpose of the present study was to evaluate the effect of three commercially available repair kits on repair bond strength, surface roughness and wettability on all‐ceramic and fibre reinforced composite materials.