• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.183-189
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• 2018

In this study, the bond strength between concrete and metal films was investigate according to changing water content ratio of substrate concrete by pull-out test in order to develop the new finishing design methods for building structures using the metal films. The following conclusions were obtained as a result of the studies. It was find that the colour of metal did not change before and after the metal spraying. Also, the water content ratio of substrate concrete must be controlled under 10% weight to confirm the standard bond strength of finishing material to concrete. 2.5 MPa. To enhance the bond strength between concrete and metal films, it is very effective to strengthen the concrete surface using the agent which strengthen the concrete surface and seal the pore of metal film by the sealing agents. Therefore, the control of concrete surface treatment and water content ratio are necessary to secure the bond strength of metal films.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.1
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• pp.147-154
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• 2020

The exterior finishing of reinforced concrete buildings is one of the important factors to prevent durability and prevent natural environment or disaster such as temperature, snow, wind, rain from the outside as well as external design of buildings. Finishing methods can be divided into wet and dry methods. The wet method using paint is relatively easy to construct, but it requires repair and reinforcement every 1 to 5 years and requires a lot of LCC for maintenance. Finishing method using panel has good durability, but it is difficult to install and expensive. Therefore, in this paper, we evaluate the bond strength for the application of the metal spray method in order to overcome the problems of existing methods. Experimental results show that the sandblast + surface roughness agent(S-R(Y)) has a roughness of 41.16 ㎛ and the bond strength is about 3.19 MPa, which is the highest bond strength. In addition, the grinding + surface roughness agent(G-R(Y)) application showed roughness of about 36.59 ㎛ and secured the bond strength performance of 2.94 MPa.

• The korean journal of orthodontics
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• v.39 no.5
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• pp.320-329
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• 2009

Objective: The aim of this study was to evaluate the effect of metal primers and thermocycling on shear bond strength between the orthodontic bracket and gold alloy. Methods: For this study, 80 specimens made of dental gold alloy were divided into 8 groups based on the combination of metal primers (none, Alloy primer, Metaltite, V-primer) and thermocycling (with and without thermocycling). Shear bond strength testing was performed with a universal testing machine. Bond failure sites were classified by a modified ARI (Adhesive Remnant Index) score. Results: All metal primer treated groups showed a significantly higher shear bond strength than the only sandblasting treated group without thermocycling (p < 0.05). There were no significant differences on shear bond strength in the groups with thermocycling (p > 0.05). Bond failure sites of the metal primer treated group without thermocycling occurred at gold alloy/adhesive interface, whereas there were no differences on bonding failure sites in the groups with thermocycling. Conclusions: These findings suggest that using metal primer on gold alloy enhances the initial bracket bond strength. But, this effect was not shown with thermocycling.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.2
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• pp.335-348
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• 1996

Retention is one of the major factors deciding the success and longevity of resin bonded restorations. The purpose of this study was to find a better resin cement and metal surface treatment method that would enhance the bonding strength. The bonding surfaces of Verabond, one of Ni-Cr-Be alloys, were treated with sandblasting(Group 1), sandblasting and EZ-Oxisor(Group 2), sandblasting and silicoating(Group 3), and than thay were bonded with All-Bond C & B, Panavia 21, Superbond C & B. The specimens were thermocycled, and the tensile bond strength was measured using the unive-rsal testing machine. Also the mode of bond failure was observed. The results were as folows. 1. The Superbond C & B showed the highest bond strength among the three resin cements and decreased in the order of Panavia 21, All-Bond C & B. There was significant differe-nce among them(p<0.05). 2. Group 3 showed the highest bond strength among the three metal surface treatment methods, and there was significant difference compared with Group 1 and Group 2(p<0.05). But there was no significant difference between Group 1 and Group 2. 3. Observing the mode of bond failure, Superbond C & B and Panavia 21 showed mostly cohesive failure in all groups. All-Bond C & B showed all types of bond failure in Group 3, but Group 1 and Group 2 showed only adhesive failure. 4. According to the results of this study, the silicoating method and 4-META containing resin cement were considered to be more acceptable for resin bonded restoration.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.2
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• pp.233-245
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• 1996

The purpose of this study was to evaluate the effect of thermocycling on bond strength between metal and resin cement according to thermocycling, and to observe the bond failure modes with optical microscope(X30). For this purpose, Super-Bond C & B and Panavia 21 resin cement were used. Metal specimens were made of Vera-Bond and the surface of specimens were sandblasted with $50{\mu}m$ aluminum oxide. All experimental groups were stored in $37^{\circ}C$ distilled water for 72 hours, followed by thermocycling between $5^{\circ}C$ and $55^{\circ}C$ with 15 second dwell time. 500, 1000, 2000 cycles of thermocycling were executed and the tensile bond strength was measured by Instron Universal Testing Machine(Model 4201) The obtained results were as follows : 1. Super-Bond C & B and Panavia 21 did not show statistically significant difference accor-ding to thermocycling test(P>0.05). 2. Super-Bond C & B specimens exhibited statistically significant higher tensile bond stre-ngth than Panavia 21 for all experimental groups(P<0.05). 3. Super-Bond C & B exhibited mixed mode failure with partial adhesive and partial cohe-sive failure, and most of Panavia 21 exhibited cohesive failure and some mixed mode failure.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.1
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• pp.1-12
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• 1995

For the purpose of this study, the silicoating on Ni-Cr-Be alloy surface was carried out by using the Silicoater MD. The effect of time delay after silicoating on the bond strength between the metal and resin cement was examined. The groups were divided into 4 : group 1 : Sandblasted with $250{\mu}m$ aluminium oxide, immediatly cemented group 2 : Sandblasted with $250{\mu}m$ aluminium oxide, silicoated and immediatly cemented group 3 : Sandblasted with $250{\mu}m$ aluminium oxide, silicoated and cemented after 7 days group 4 : Sandblasted with $250{\mu}m$ aluminium oxide, silicoated and coated with unfilled resin and cemented after 7 days Specimens were luted with Comspan, Superbond C&B or Panavia EX. The tensile bond strength between the metal and resin cement was measured by using the universal testing machine. The results were as follows : 1. The bond strength in groups 2, 3 and 4 was higher than that of group 1 (p<0.05). There was no statistically significant difference among the bond strength in groups 2, 3 and 4 (p>0.05). 2. In Comspan-cemented groups, there was no significant difference among the bond strength in groups 2, 3 and 4 (p<0.05). 3. In Panavia EX-cemented groups, the bond strength of group 3 was higher than that of group 2 (p<0.05) and there was no significant difference between groups 3 and 4. 4. In Superbond C&B-cemented groups, there was significant difference between groups 2 and 3 (p<0.05) and the bond strength of group 4 was higher than that of group 3 (p<0.05). 5. The highest tensile bond strength was obtained by using the Superbond C&B and no difference in the Panavia EX and Comspan. 6. The modes of bond failure were mainly cohesive failure. The method of storage and transport indicated in this study seems recommendable for laboratory and clinical use at least up to 7 days.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.135-154
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• 1992

This study was performed to analyze bond strength, the alterations of the interfaces between metal films which are populary used and considered to contribute to the chemical reaction with porcelain, according to constant ion- beam- mixing, and the relation between interfacial chemical reactions and bond strength in metal/porcelain specimens. For this study, three seperate metals : selected-gold, indium and tin were chosen ; each to be bonded to a seperate body porcelain. Bonding occurs when the metal is deposited to the body porcelain using a vacuum evaporator. The vacuum evaporator used $10^{-5}\sim10^{-6}$ Torr vacuum states for the evaporation of various metals (Au, Sn, In). Ion-beam-mixing of the porcelain/metal interfaces caused reactions when the Ar+ was implanted into thin films using a 80 KeV accelerator. These ion-beam-mixed specimens were then compared with an unmixed control group. An analysis of bond strength and ionic changes between the the metal and porcelain was performed by electron spectroscopy of chemical analysis (ESCA) and scratch test. The finding led to the following conclusions : 1. Light microscopic views of the scratch test : The ion-beam-mixed Au/porcelain specimen showed narrower scratched streams than the unmixed specimen. However, the Sn/porcelain, In/porcelain specimens showed no differences in the two conditions. 2. Acoustic emissions in scratch tests : The ion-mixed Au/porcelain, In/porcelain specimens showed signals closer to the metal/porcelain interfaces than unmixed specimens. Conversely, the ion-mixed Sn/porcelain specimen showed more critical signals in superficial portions than unmixed specimens. 3. After ion- beam-mixing, the Au/porcelain specimen showed apparently increased bond strength, and the In/porcelain specimen showed very slightly increased bond strength. However, the Sn/porcelain specimen showed no differences between ion mixed specimen and the unmixed one. 4. ESCA analysis : The ion-beam-mixed Au/porcelain specimen showed a higher peak separated value (4.3eV) than that of the unmixed specimen(3.65eV), the ion-beam-mixed In/porcelain specimen showed a higher peak separated value (9.43eV) than that of the unmixed specimen(7.6eV) and the ion-beam-mixed Sn/porcelain specimen showed a higher peak separated value (8.79eV) than that of the unmixed specimen(8.5eV). 5. Interfacial changes were observed in the ion-mixed Au/porcelain, In/porcelain and Sn/porcelain specimens. Especially, significant interfacial changes were measured in the ion- mixed Sn/porcelain specimen. Tin dioxide(SnO2) and a combination of pure tin and tin dioxide (Sn+SnO2) were produced. 6. In the Au/porcelain specimen, the interfacial chemical reaction showed increased bond strength between gold and porcelain substrate. But, in the In/porcelain, Sn/porcelain specimens, interfacial chemical reactions did not affected the bond strength between metal and porcelain substrate. Especially, bonding strength on the ion mixed Sn/porcelain specimen showed the least amount of difference.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.1
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• pp.78-94
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• 1997

The purpose of this experiment was to determine the effects of various treatments on denture base resin to metal bond for cobalt-chromium alloy. The metal surface was treated as follows. Group 1 : Sandblasted with $50{\mu}m$ aluminum oxide. Group 2 : Sandblasted with $250{\mu}m$ aluminum oxide. Group 3 : Sandblasted with $250{\mu}m$ aluminum oxide and followed by silicoating. Group 4 : Electrochemically etched. Group 5 : treated with oxidizing solution. Group 6 : Beaded with $200{\mu}m$ retention structure and followed by silicoating. All specimens were applied with 4-META resin and were thermocycled 1000 times at temperature of $5^{\circ}C$ to $55^{\circ}C$. The effects of various surface treatments on the bond strength between 4-META resin and metal interface were measured by using the universal testing machine. All specimens were observed with SEM. The results were as follows 1. The bond strength of 4-META resin were significantly higher to Co-Cr alloy. 2. The bond strength decreased in the following orders : group 6, group 3, groups 1 and 2, group 4, group 5 and there was no statistically significant difference in bond strength among groups 1 and 2.(p>0.05) 3. The bond strength of cobalt-chromium alloy to 4-META resin were not significantly different.(p>0.05) 4. The treated surface of groups 1, 2 and 3 has more fine undercut than that of groups 4 and 5 with SEM. 5. Stable adhesion can be achieved when mechanically roughened metal surface by sandblasting than treating in an electrochemical etching and an oxidizing solution with potassium manganate.

• The Journal of Advanced Prosthodontics
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• v.7 no.5
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• pp.392-399
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• 2015

PURPOSE. The aim of this study was to evaluate the effect of metal primers on the bonding of dental alloys and veneer resin. Polyvinylpyrrolidone solution's tarnish effect on bonding strength was also investigated. MATERIALS AND METHODS. Disk-shape metal specimens (diameter 8 mm, thickness 1.5 mm) were made from 3 kinds of alloy (Co-Cr, Ti and Au-Ag-Pd alloy) and divided into 4 groups per each alloy. Half specimens (n=12 per group) in tarnished group were immersed into polyvinylpyrrolidone solution for 24 hours. In Co-Cr and Ti-alloy, Alloy Primer (MDP + VBATDT) and MAC-Bond II (MAC-10) were applied, while Alloy Primer and V-Primer (VBATDT) were applied to Au-Ag-Pd alloys. After surface treatment, veneering composite resin were applied and shear bond strength test were conducted. RESULTS. Alloy Primer showed higher shear bond strength than MAC-Bond II in Co-Cr alloys and Au-Ag-Pd alloy (P<.05). However, in Ti alloy, there was no significant difference between Alloy Primer and MAC-Bond II. Tarnished Co-Cr and Au-Ag-Pd alloy surfaces presented significantly decreased shear bond strength. CONCLUSION. Combined use of MDP and VBATDT were effective in bonding of the resin to Co-Cr and Au-Ag-Pd alloy. Tarnish using polyvinylpyrrolidone solution negatively affected on the bonding of veneer resin to Co-Cr and Au-Ag-Pd alloys.

• The Journal of Advanced Prosthodontics
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• v.3 no.3
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• pp.166-171
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• 2011

PURPOSE. The purpose of this study is to evaluate and compare the shear bond strength of the gingiva-colored composite resin and the tooth-colored composite resin to porcelain, metal and zirconia. MATERIALS AND METHODS. Sixty cylindrical specimens were fabricated and divided into the following 6 groups (Group 1-W: tooth-colored composite bonded to porcelain, Group 1-P: gingiva-colored composite bonded to porcelain, Group 2-W: tooth-colored composite bonded to base metal, Group 2-P: gingiva-colored composite bonded to base metal, Group 3-W: tooth-colored composite bonded to zirconia, Group 3-P: gingiva-colored composite bonded to zirconia). The shear bond strength was measured with a universal testing machine after thermocycling and the failure mode was noted. All data were analyzed using the two-way analysis of variance test and the Bonferroni post-hoc test at a significance level of 0.05. RESULTS. The mean shear bond strength values in MPa were 12.39, 13.42, 8.78, 7.98, 4.64 and 3.74 for Group 1-W, 1-P, 2-W, 2-P, 3-W and 3-P, respectively. The difference between the two kinds of composite resin was not significant. The shear bond strength of Group 1 was the highest and that of Group 3 was the lowest. The differences among Group 1, 2 and 3 were all significant (P<.05). CONCLUSION. The shear bond strength of the gingiva-colored composite was not less than that of the tooth-colored composite. Thus, repairing or fabricating ceramic restorations using the gingiva-colored composite resin can be regarded as a practical method. Especially, the prognosis would be fine when applied on porcelain surfaces.