• Bulletin of the Korean Chemical Society
• /
• v.32 no.7
• /
• pp.2473-2475
• /
• 2011

• Journal of Technologic Dentistry
• /
• v.7 no.1
• /
• pp.19-25
• /
• 1985

In oder to compare and measure bond strength of ceramometal system with use of ceramco porcelain powder including SnO2 and uni metal, Rexillium III, Vera Bond as non precious alloys manufactured for porecelain-metal restorations. Total 24 test sample were constructed. All Test sample were measured with a Mitutoyo micrometer graduated to 0.01mm. It is as follows measured of thickness 3.3mm(metal : 1.1mm, porcelain: 2.2mm), width 12mm, length 30mm(porcelain 12mm x 12mm), Compared maximum bending stress test. The results obtained were as follows: 1. Bond strength of each metal with ceramco porcelain powder showed statistical significance.(P<0.05) 2. Vera Bond and uni metal, uni metal and Rexillium III revealed no statistical Significance.(P>0.05) Vera Bond and Rexillium III showed statistical significance.(P<0.05) 3. The order of maximum bending stress was Rexillium III, uni metal, vera Bond. The order of bond strength ratio making bending stress was Vera bond, uni metal, Rexillium III.

• The Journal of Korean Academy of Prosthodontics
• /
• v.39 no.4
• /
• pp.351-365
• /
• 2001

For accurate impression taking, accurate impression material, solid individual tray, and bond strength between impression materials and resin tray are important factors. The purpose of this study was to evaluate tensile bond strength of rubber impression materials to various tray resin materials. This study tested the time dependent tensile bond strength between commercial brands or poly ether, polysulfide, additional silicone impression materials and commercial brands of self curing tray resin. light activited tray resin when applying adhesive Resin specimens were made with 20mm in diameter, 2mm in thickness. 1 made total 360 specimens, 10 per each group and the tensile bond strength was measured by using the Instron($M100EC^{(R)}$, Mecmesin Co., England). The results were as follows ; Comparisons of various impression materials. 1. In case of Impregum $F^{(R)}$, the bond strength of tray resin was decreased in order of SR $Ivolen^{(R)}$, Ostron $100^{(R)}$ Instant tray $mix^{(R)}$, $Lightplast^{(R)}$. All groups excluding Ostron $100^{(R)}$, Instant tray $mix^{(R)}$ are significant difference (p<0.05). Drying time after applying adhesive, the tensile bond strength of tray resin was insignificantly decreased in order of 10 min drying time group. 1 min drying time group. 5 min drying time group. 2. In case of Permlastic $regular^{(R)}$ the bond strength of tray resin was insignificantly decreased in order of Ostron $100^{(R)}$. SR $Ivolen^{(R)}$, Instant tray $mix^{(R)}$ $Lightplast^{(R)}$. About drying time after applying adhesive, the tensile bond strength of tray resin was significantly decreased in order of 5 min drying time group, 10 min drying time group, 1 min drying time group(p<0.05). 3. In case of Exaflex $regular^{(R)}$. the bond strength of tray resin was decreased in order of $Lightplast^{(R)}$, SR $Ivolen^{(R)}$, Instant tray $mix^{(R)}$, Ostron $100^{(R)}$. $Lightplast^{(R)}$ was significant difference(p<0.05). About drying time after applying adhesive, the tensile bond strength of tray resin was decreased in order of 5 min drying time group, 10 min drying time group, 1 min drying time group(p<0.05). Especially 5 min ding time group was significant difference(p<0.05). According to the results of this study, we can see the greatest tensile bond strength when using Impregrm $F^{(R)}$ and Permlastic $regular^{(R)}$ with self curing tray resin, when using Exaflex $regular^{(R)}$ with light activated tray resin In my opinion, adhesive should be dried more than 5 min before impression taking to achieve the greatest tensile bond strength.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.23 no.2
• /
• pp.347-355
• /
• 1996

The purpose of this study was to compare the bond strengths of different kinds of glass ionomer cements (GIC), which is recently increasing the clinical application in the field of pediatric dentistry and measure the repaired bond strengths in order to examine the clinical applicabilty of partial repaired cases. By using one kind of the light cured type GIC and three kinds of the chemical cured type GIC, the bond strengths of the followings were compared : unrepaired group as control, repaired conditioning group, which was treated the repaired surface using 25% polyacrylic acid and repaired non-conditioning group without surface treatment. Three point bending test was performed under Universal Testing Machine in order to measure the compressive bond strengths. The results were as follows : 1. Light cured GIC had higher bond strength than chemical cured type GIC in both of repaired and unrepaired groups. 2. In repaired cases, all of the materials decreased the bond strength when compared to the control group. In the light cured type, the bond strength of repaired conditioning group decreased 31.6%, repaired non-conditioning group decreased 40.8%. In chemical cured types, the bond strength of repaired conditining group decreased 11.8%, repaired non-conditioning group decreased 20.9%. 3. All the materials, in the case of the chemical treatment on the repaired surface using 25% polyacrylic acid had higher bond strength than untreated but, lower than control group.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.11a
• /
• pp.234-237
• /
• 2003

Previous researches about headed reinforcement have not been concerned about bond failure which is quite important is some cases. In this paper, failure mechanism including bond failure was presented in order to define the contribution of bond stress at the time failure occurs. Examined with design codes and test results, it is proved to be rational to consider the contribution of bond stress in determining the ultimate pull-out capacity of headed reinforcement. Direct adaptation of design code for anchor bolt without modification for the contribution of bond stress will lead to underestimate the capacity of headed reinforcement.

• Restorative Dentistry and Endodontics
• /
• v.29 no.4
• /
• pp.353-364
• /
• 2004

The purpose of this study was to compare and to evaluate the combination use of 5 kinds of dentin adhesive systems and 5 kinds of composite resins using micro-shear bond test. Five adhesive systems (Prime & Bond NT (PBN). Onecoat bond (OC), Excite (EX), Syntac (SY), Clearfil SE bond (CS)) and five composite resins (Spectrum (SP), Synergy Compact (SC), Tetric Ceram (TC), Clearfil AP-X (CA), Z100 (Z1)) were used for this study ($5{\;}{\times}{\;}5{\;}={\;}25group$, n =14/group). The slices of horizontally sectioned human tooth were bonded with each bonding system and each composite resin, and tested by a micro-shear bond strength test. These results were analyzed statistically. The mean micro-shear bond strength of dentin adhesive systems were in order of CS (22.642 MPa), SY (18.368 MPa), EX (14.599 MPa). OC (13.702 MPa). PBN (12.762 MPa). The mean bond strength of self-etching primer system group (CS, SY) in dentin was higher than that of self-priming adhesive system groups (PBN, EX, OC) significantly (P<0.05). The mean bond strength of composite resins was in order of SP (19.008 MPa), CA (17.532 MPa). SC (15.787 MPa), TC (15.068 MPa). Z1 (14.678 MPa). Micro-shear bond strength of SP was stronger than those of other composite resins significantly (P < 0.05). And those of TC and Z1 were weaker than other composite resins significantly (P < 0.05). No difference was found in micro-shear bond strength of composite resin in self-etching primer adhesive system groups (CS, SY) statistically. However, there was significant difference of micro-shear bond strength of composite resin groups in self-priming adhesive systems group (PBN, EX, OC). The combination of composite resin and dentin adhesive system recommended by manufacturer did not represent positive correlation. It didn't seem to be a significant factor.

• Restorative Dentistry and Endodontics
• /
• v.21 no.1
• /
• pp.280-288
• /
• 1996

The purpose of this study was to assess comparatively the shear bond strength on dentin of four dentin bonding agents used in conjunction with light-curing composite resins. Clearfil New Bond, Scotchbond Multipurpose Dentin Adhesive, All-Bond 2 and X-R Bond were applicated on labial dentin surfaces just below dentin - enamel juction of bovine incisor teeth. After shear bond strength testing with the universal testing machine, the bonding interface of the specimens were observed under light stereomicroscope. Following results were obtained. 1. The shear bond strength was high in the order of B,C,D,A and group B Scotchbond Multipurpose Dentine Adhesive revealed greater bond strength than Clearfil New Bond and X-R Bond. (p<.001) 2. When using ANOVA and Duncan's multiple range test, there were statistical differences among the four groups, except between group Band C,group D and A. 3. There was no relationship between mode of failure and shear bond strength.

• The Journal of Korean Academy of Prosthodontics
• /
• v.39 no.2
• /
• pp.157-170
• /
• 2001

The bond strength is the most important factor in establishing long-term success of resin-retained fixed prostheses. So, various surface treatment methods have been introduced to improve the bond strength of metal surface and bonding resin till now This study was performed to compare the effect of silicoating with that of metal primer and analyze the correlation between treatment time of sandblasting and the bond strength, so that meant to find more effective surface treatment method that could enhance the bond strength of resin-retained fixed prostheses. The surfaces of all specimens made of $Verabond^{(R)}$ alloys were air abraded with $250{\mu}m\;Al_2O_3$ according to treatment time of sandblasting and they were subdivided to be treated with only sandblasting(S group), silicoating following sandblasting(SS group) and metal primer application after sandblasting(SM group). Then pairs of metal specimens (${\phi}10mm{\times}h\;2mm,\;{\phi}6{\times}h\;2mm$) were bonded with Super bond $C&B^{(R)}$. The specimens were stored in $38^{\circ}C$ water for 48 hours and shear bond strength was measured using the universal testing machine. The results were as follows, 1. In the comparison of shear bond strength according to treatment time of sandblasting, bond strength was increased in the order of 0', 15', 30', 45', 60' group. 0' group had significantly lower value than any other, while 0', 15' group were significantly different with 30', 45', 60' group(p<0.05). 2. In the comparison of shear bond strength according surface treatment methods, bond strength was increased in the order of S group. SS group and SM group. S group was significantly different with SS group and SM group(p<0.05). 3. Observing the mode of bond failure. 0', 15' group showed only adhesive failure, and 30', 45', 60' group did mostly adhesive & cohesive failure in S group. In SS group and SM group, all other groups except 0', 15' group showed mostly cohesive failure. From the above results, it is considered that sandblasting should be treated for more than 30 seconds, and metal primer be more effective and available clinically than silicoater system which is complicate, technique-sensitive and time-consuming method, when nonprecious metal surface is planning be treated with in order enhance the bond strength of resin-retained fixed prostheses.

• Journal of Technologic Dentistry
• /
• v.41 no.4
• /
• pp.279-285
• /
• 2019

Purpose: The dental CAD / CAM system has been popular with the development of the digital dental industry. Zirconia is a typical material in dental CAD / CAM systems. Zirconia crowns are classified into single layer and double layer. This study is about the double layer crown of zirconia. The surface roughness, bond strength and fracture patterns of the zirconia surface were observed. Methods: Zirconia blocks were cut using a low speed cutter. Sintered to form a plate shape (6mm × 6mm × 3mm). The prepared specimens were surface treated in four ways. Surface roughness and bond strength were measured. And the fracture pattern was observed. Results: Result of surface treatment of zirconia. The surface roughness test results were as ET 2.87 ㎛, ST 2.67 ㎛, LT 2.44 ㎛, AT 2.41 ㎛, CN 2.08 ㎛ order. Bond Strength results were as LT 25.09 MPa, AT 23.27 MPa, ST 21.27 MPa, ET 21.09 MPa, CN 16.12 MPa order. Fracture patterns showed cohesive failure of 25-50% of the bond area. Conclusion: Surface roughness, bond strength and fracture pattern of the zirconia surface were observed. Etching the surface treatment of zirconia materials has been shown to affect the surface roughness. Zirconia special binder treatment has been shown to affect the bond strength improvement.

• Computers and Concrete
• /
• v.2 no.1
• /
• pp.1-18
• /
• 2005

This paper presents a study on the effects of localized steel-concrete bond degradation on the flexural behaviour of RC beams. A finite element analysis is undertaken to complete the experimental analysis. The first part deals with an experimental study on beams where bond was removed by using plastic tube at different locations and for various lengths. The flexural behaviour was studied at global scale (load-deflection) and local scale (moment-curvature). The second part, a numerical study using a simplified special finite element (rust element) modelling the rust layer occurring between reinforcement and concrete with corrosion was conducted in order to find the relation between the degree of corrosion and the degradation of the steel-concrete bond. The computed value of the corrosion degree corresponding to the total degradation of bond has been used in a second time to model the tests, in order to evaluate the influence of the loss of bond, the steel cross section reduction, and the combination of both. The results enable to evaluate the influence of the different corrosion effects on the flexural behaviour, according to the length and the location of the corroded zone.