• The Journal of Advanced Prosthodontics
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• v.9 no.4
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• pp.257-264
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• 2017

PURPOSE. To evaluate the adhesion to CAD/CAM feldspathic blocks by failure analysis and shear bond strength test (SBSt) of different restorative systems and different surface treatments, for purpose of moderate chipping repair. MATERIALS AND METHODS. A self-adhering flowable composite (Vertise Flow, Kerr) containing bi-functional phosphate monomers and a conventional flowable resin composite (Premise Flow, Kerr) applied with and without adhesive system (Optibond Solo Plus, Kerr) were combined with three different surface treatments (Hydrofluoric Acid Etching, Sandblasting, combination of both) for repairing feldspathic ceramics. Two commercial systems for ceramic repairing were tested as controls (Porcelain Repair Kit, Ultradent, and CoJet System, 3M). SBSt was performed and failure mode was evaluated using a digital microscope. A One-Way ANOVA (Tukey test for post hoc) was applied to the SBSt data and the Fisher's Exact Test was applied to the failure analysis data. RESULTS. The use of resin systems containing bi-functional phosphate monomers combined with hydrofluoric acid etching of the ceramic surface gave the highest values in terms of bond strength and of more favorable failure modalities. CONCLUSION. The simplified repairing method based on self-adhering flowable resin combined with the use of hydrofluoric acid etching showed high bond strength values and a favorable failure mode. Repairing of ceramic chipping with a self-adhering flowable resin associated with hydrofluoric acid etching showed high bond strength with a less time consuming and technique-sensitive procedure compared to standard procedure.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.48-54
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• 2001

The effects of additives in the HCI etching solution on etching behaviors of aluminum foil as dielectric film for electrolytic capacitors were investigated. The etch pits formed in 1M hydrochloric acid containing ethylene glycol as an additive contain more fine and homogeneous etch tunnels compared to those in 1 M hydrochloric acid only, which led to the increase in the effective internal surface area of aluminum foil. After anodizing of aluminum foil etched in etching solutions, the LCR meter results have shown that the capacitance of dielectric film etched in hydrochloric acid with ethylene glycol was increased remarkably compared to that etched in hydrochloric acid only.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.3
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• pp.375-381
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• 2007

Statement of problem. Prior to determining an optimal width of micropatterned grooves provided on titanium substrata, we have done a pilot study using surface topographies in combined microm and submicrom levels. Purpose. The purpose of this study was twofold 1) to assess the proliferation and 2) to analyze the expression of genes encoding the intracellular signaling proteins involved in cell-substratum adhesions and adhesion-dependent G1 phase cell cycle progression of human gingival fibroblasts plated on smooth and microgrooved/acid-etched titanium substrata. Material and methods. Three groups of titanium discs as NE0 (smooth Ti substrata), E15 (Ti substrata with microgrooves of $15{\mu}m$ of spacing and $3.5{\mu}m$ in depth and with further acidetching), and E30 (Ti substrata with microgrooves of $30{\mu}m$ spacing and $3.5{\mu}m$ in depth and with further acid-etching) served as the human gingival fibroblasts' substrata. Viability and proliferation of fibroblasts were determined using an XTT assay. Gene expressions of fibronectin, ${\alpha}5$ integrin, CDK4, and $p27^{kip}$ were analyzed in RT-PCR. Cell-substratum interactions were analyzed in SEM. Results. From the XTT assay at 24 h incubation, the mean optical density (OD) value of E15 was significantly greater than the values of E30 and NE0. At 48 and 96 h however, the mean OD values of E30 were significantly greater than the values of E15 and NE0. No differences in the expression of PCR transcripts at 96 h incubations were noted between groups, whereas at 48 h, an unexpected increase in the expression of all the transcripts were noted in E15 compared with other two groups. Fibroblasts were observed to orient and adhere inside the microgrooves. Conclusion. Micropatterned grooves and acid-etching on Ti substrata alter viability and gene expression of adhered human gingival fibroblasts.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.618-618
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• 2003

The purpose of this study was to evaluate the etching effects and bond strength of total etching and self-etching adhesive system on unground enamel using scanning electron microscopy and microtensile bond strength test. The buccal coronal unground enamel from human extracted molars were prepared using low-speed deamond saw. Scotchbond Multi-Purpose(group CM), Clearfil SE Bond(group SE), or Adper Prompt L-pop(group LP) were applied to the prepared teeth, and resin compasite(Z-250) was built up incrementally. Resin tag formation were evaluated by scanning electron microscopy, after removal of enamel surface by acid dissolution and dehydration.(중략)

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.410-415
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• 1999

The adhesion strength of sputtered copper films to Inconel substrates has been studied using the scratch test. The effects of substrate treatments before deposition such as chemical or ion bombardment etching were investigated by means of a mean critical load derived from a Weibull-like statistical analysis. It was found that the mean critical load was very weak unless the amorphous layer produced by mechanical polishing on the substrate surface was eliminated. Chemical etching in a nitric-hydrochloric acid bath was shown to have practically no effect on the enhancement of the adhesion. In contrast, the addition in this bath of nickel and copper sulphates allowed removal of the amorphous layer and an increase in the values of the mean critical load. However, it was observed that excessive chemical etching could cancel out the mean critical load enhancement. The results obtained in the case of ion bombardment etching pretreatments could be far higher than those obtained with chemical etching. Moreover, for a sufficiently long period of ion bombardment etching, the adhesion strength was so high that it was impossible to observe evidence of an adhesion failure.

• Restorative Dentistry and Endodontics
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• v.5 no.1
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• pp.7-12
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• 1979

After applying three types of composite resins - Hi-Pol composite with Enamel bond, Hi-Pol composite without Enamel bond, Restodent - to the intact and the ground surface of tooth that had been acid etched for one or two minutes, the author observed the penetration of these resins into the acid etched enamel surface with scanning electron microscope. The results were as follows. 1. All the experimented materials showed the penetration into the acid etched enamel surface, and the average depth of penetration was 7 microns. 2. There was no significant difference in the penetration of these three resins despite different etching, time. 3. The grinding of the Enamel surface before acid - etching was not effective in altering the depth of penetration of these materials.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.4
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• pp.323-334
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• 2002

The purpose of this study is to investigate which current densities and etching times will result in an optimal etching depth and surface roughness when an Ni-Cr-Be alloy is etched with 30% perchloric acid($HClO_4$). For this study, observations were made by means of an optical three-dimensional surface roughness measuring machine and a scanning electron microscope. The etchings took place under the following conditions using current densities of $300mA/cm^2\;450mA/cm^2,\;600mA/cm^2$ and $750mA/cm^2$, and using etching time of three, five, six, seven and nine minutes. Under the conditions, the experiments reached the following conclusions. 1. When the current density is above $450mA/cm^2$ and the etching time is longer than five minutes, the etching depth increased as the current density and etching time increased. And the surface roughness was significantly influenced by the interaction of the current density and etching time. 2. Under the etching conditions of $600mA/cm^2$ and five minutes, the optimal etching depth for a resin cement space and the highest surface roughness for mechanical retention were obtained. The etching depth and surface roughness were $32.86{\mu}m$ and $7.90{\mu}m$, respectively. 3. Observations under the scanning electron microscope showed that both the corrosion at the grain boundary and the corrosion within the grain occurred on the etched surface. It was also observed that the corrosion at the grain boundary became more severe as the current density and etching time increased. In addition. at higher current densities and longer etching times general corrosion appeared.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.2
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• pp.149-159
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• 2006

Statement of problem. Porcelain repair mainly involves replacement with composite resin, but the bond strength between composite resin and all-ceramic coping materials has not been studies extensively. Purpose. The objective of this study was to investigate the influence of composite resin and ceramic etching pattern on shear bond strength of Empress2 ceramic and observe the change of microstructure of ceramic according to etching methods. Material and methods. Eighty-five cylinder shape ceramic specimens (diameter 5mm, IPS Empress 2 core materials) embeded by acrylic resin were used for this study. The ceramic were specimens divided into sixteen experimental groups with 5 specimens in each group and were etched with phosphoric acid(37%, 65%) & hydrofluoric acid (4%, 9%) according to different etching times(30s, 60s, 120s 180s). All etched ceramic surfaces were examined morphologically using SEM(scanning electron microscopy). Etched surfaces of ceramic specimens were coated with silane (Monobond-S) & adhesive(Heliobond) and built up composite resin using Teflon mold. Accomplished specimens were tested under shear loading until fracture on universal testing machine at a crosshead speed 1mm/min; the maximum load at fracture(kg) was recorded. Shear bond strength data were analyzed with one way ANOVA and Duncan tests.(P<.05) Results. Maximum shear bond strength was $30.07{\pm}2.41(kg)$ when the ceramic was etched with 4% hydrofluoric acid at 120s. No significant difference was found between phosphoric etchant group and control group with respect to shear bond strength. Conclusion. Empress 2 ceramic surface was not etched by phosphoric acid, but etched by hydrofluoric acid.

• Applied Science and Convergence Technology
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• v.25 no.1
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• pp.15-18
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• 2016

Study investigated the optimal anodizing conditions for fabricating an oxide film that produces less contamination in a corrosive plasma environment, using oxalic acid and tartaric acid. Oxide films were produced using sulfuric acid, oxalic acid, and tartaric acid electrolyte mixtures with various mole ratios. The oxide film made by adding 0.05M tartaric acid to 0.3M oxalic acid showed higher breakdown voltage and lower leakage current. Additionally, contamination particles were reduced during plasma etching, thus demonstrates that this mixture presented optimal conditions. However, higher tartaric acid content (0.1 M, 0.15 M) led to lower breakdown voltages and higher leakage currents. Also, it resulted in more cracking during thermal shock tests as well as the generation of more contamination particles during plasma processing.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.272-277
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• 2014

In this study the nanofiltration (NF) membrane treatment of a sulfuric acid waste solutions containing copper ion ($Cu^{+2}$) discharging from the etching processes of the printed circuit board (PCB) manufacturing industry has been studied for the recycling of acid etching solution. SelRO MPS-34 4040 NF membrane from Koch company was tested to obtain the basic NF data for recycling of etching solution and separation efficiency (total rejection) of copper ion. NF experiments were carried out with a cross-flow membrane filtration laboratory system. The permeate flux was decreased with the increasing copper ion concentration in sulfuric acid solution and lowering pH of acid solution, and its value was the range of $4.5{\sim}23L/m^2{\cdot}h$. Total rejection of copper ion was decreased with the increasing copper ion concentration, lowering pH of acid solution and decreasing cross-flow rate. The total rejection of copper ion was more than 70% at the experimental condition. The SelRO MPS-34 4040 NF membrane was represented the stable flux and rejection for 1 year operation.