• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.293-299
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• 2005

It is important to reduce chair time and procedure in restorative treatment for children. Composite resin is not only used in esthetic restoration of anterior teeth but also posterior teeth by its improved physical property. The 7th generation dentin bonding system was recently developed in order to simplify three steps which is needed to bond composite resin to tooth surface-etchant, primer, adhesive. We compared shear bond strengths of 4, 5, 6, 7th generations dentin bonding systems. The primary dentin was pretreated with 4, 5, 6, 7th generation dentin bonding systems. Then composite resin was cured to the specimen using molds 2.5mm in diameter and 2mm in height. Thermocycling was performed and shear bond strength was finally measured. The results were as follow; 1. The mean values of shear bond strengths in 5th generation dentin bonding system(group 2) were greater than those of 4, 6, 7th generation dentin bonding system(group 1, 3, 4). The differences were statistically significant. 2. The mean values of shear bond strengths in 4th generation dentin bonding system(group 2) were greater than those of 6, 7th generation dentin bonding system(group 1, 3, 4). But, the differences were not statistically significant. 3. Between the mean values of shear bond strengths in 6, 7th generation dentin bonding system(group 3, 4) were similar.

• Journal of the Korea Concrete Institute
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• v.20 no.2
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• pp.165-173
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• 2008

One of the most important requirements for reinforced concrete constructions is the bond behavior between concrete and reinforcement. For practical application, it is very important to study bond behavior of reinforcing bars in recycled aggregate concrete (RAC). Thirty six pull-out tests were carried out in order to investigate the bond behaviour between recycled coarse aggregate concrete (RCAC) and deformed bars. RCA replacement ratios (i.e., 0%, 30%, 60% and 100%) and positions of deformed bar (i.e., vertical and horizontal position) were considered as variables in this paper. Each specimen was in the form of a cube, with edges of 150 mm in length and for the pull-out tests, a deformed bar, 13 mm in diameter, was embedded in the center of each specimen. Based on the test results, the bond strength between the RCAC and deformed bars were influenced by both RCA replacement ratios and positions of deformed bars. It was found that under the equivalent mix proportion (i.e., the mix proportions are the same, except for different RCA replacement ratios), the bond strength between the RCAC and the ribbed bar has no obvious relation with the RCA replacement ratio, whereas the positions of deformed bars have a significant effect on the bond behavior between the RCAC and deformed bars. Under the condition of same RCA replacement ratio, the specimen of horizontal reinforcement at upper position (HU type) appear considerably low bond stress.

• Restorative Dentistry and Endodontics
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• v.34 no.3
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• pp.223-231
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• 2009

The purpose of this study was to evaluate the effect of a desensitizer on dentinal bond strength in cementation of composite resin inlay. Fifty four molar teeth were exposed the occlusal dentin. Class I inlay cavities were prepared and randomly divided into six groups. Control group: no agent, Group 1 : Isodan, Group 2 : One-step, Group 3 : All-Bond SE, Group 4 : Isodan + One-step, Group 5 : Isodan + All-Bond SE. Desensitizing agent and dentin bonding agents were applied immediately after the completion of the preparations. Impressions were then made. The composite resin inlays (Tescera, Bisco) were fabricated according to the manufacturers' guidelines. Cementation procedures followed a standard protocol by using resin cement (Bis-Cem, Bisco). Specimens were stored in distilled water at $37^{\circ}C$ for 24 hours. All specimens were sectioned to obtained sticks with $1.0{\times}1.0\;mm^2$ cross sectional area. The microtensile bond strength (${\mu}TBS$) was tested at crosshead speed of 1 mm/min. The data was analyzed using one way ANOVA and Tukey's test. Scanning electron microscopy analysis was made to examine the details of the bonding interface, 1. Group 1 showed significantly lower ${\mu}TBS$ than other groups (p<0.05). 2. There was no significant difference between the ${\mu}TBS$ of Group 3 and Group 5. 3. The ${\mu}TBS$ of Group 4 showed significantly lower than that of Group 2 (p<0.05). In conclusion, a desensitizer (Isodan) might have an adverse effect on the bond strength of composite resin inlay to dentin.

• Restorative Dentistry and Endodontics
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• v.36 no.1
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• pp.50-58
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• 2011

Objectives: The purpose of this study was to compare the microshear bond strength (uSBS) of two totaletch and four self-etch adhesive systems and a flowable resin to enamel. Materials and Methods: Enamels of sixty human molars were used. They were divided into one of six equal groups (n = 10) by adhesives used; OS group (One-Step Plus), SB group (Single Bond), CE group (Clearfil SE Bond), TY group (Tyrian SPE/One-Step Plus), AP group (Adper Prompt L-Pop) and GB group (G-Bond). After enamel surfaces were treated with six adhesive systems, a flowable composite resin (Filek Z 350) was bonded to enamel surface using Tygon tubes. the bonded specimens were subjected to uSBS testing and the failure modes of each group were observed under FE-SEM. Results: 1. The uSBS of SB group was statistically higher than that of all other groups, and the uSBS of OS, SE and AP group was statistically higher than that of TY and GB group (p < 0.05). 2. The uSBS for TY group was statistically higher than that for GB group (p < 0.05). 3. Adhesive failures in TY and GB group and mixed failures in SB group and SE group were often analysed. One cohesive failure was observed in OS, SB, SE and AP group, respectively. Conclusions: Although adhesives using the same step were applied the enamel surface, the uSBS of a flowable resin to enamel was different.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.430-438
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• 2004

This study evaluated the influence of application time of self-etching primers on microtensile bond strength (${\mu}$TBS) to dentin using three self-etching primer adhesive systems. Dentin surfaces were exposed from forty-eight human molars. They were conditioned with three self-etching primers (Clearfil SE Bond [SE], Unifil Bond [UF], Tyrian SPE + One Step Plus [TY]) and different primining times (10s, 20s, 30s and 40s). Composite resins were bonded to dentin surfaces and specimens were made. ${\mu}TBS$ was tested and statistically compared using by one-way ANOVA and Tukey's Test. The results of this study presented that priming time for 10s in SE and UF groups and for 30s and 40s in TY group was highly decreased ${\mu}TBS$ to dentin.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.85-89
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• 2000

There has recently been some trials to add the fluoride-releasing property to existing fissure sealants and some of them are already commercially available. But, some questions mat naturally be arisen regarding the potential decrease of physical properties by adding the fluoride despite its new caries-inhibiting abilities. This study was performed for the purpose of comparing the shear bond strengths of conventional composite sealant, Fluoride-releasing sealant and glass ionomer sealant, and obtained the results as fellows. 1. Two kinds of composite sealants (Helioseal and Teethmate-A) showed slightly higher bond strength than Fluoride-releasing sealant(Teethmate-F) without any significance(p>0.05). 2. Class ionomer sealant (Fuji III) was much lower than composite sealant in shear bond strength(p<0.05). 3. With the result of this study, it was found that there is little effect on retentive properties of sealants by adding fluoride to amplify the caries-inhibiting properties.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.675-682
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• 2011

Recently, in retrofit of RC structures using FRP (Fiber Reinforced Polymer), researches about Near-Surface-Mounted Rertofit (NSMR) method have been widely performed. In NSMR, FRP bar is normally inserted in the slit formed in the cover concrete and then bonded by using epoxy mortar. In this paper, the bond characteristic of NSMR using FRP plate instead of bar was studied experimentally. Fracture behavior is observed from bond test using the parameters of embedment length, shear key, and FRP plate layer. In addition, an equation to predict the splitting strength of NSMR using FRP is proposed using the test result. The results showed that when the longer embedment length and more layers of FRP are used, the higher bond strength is achieved. There was a good co-relationship between the test and calculated results using the proposed equation.

• Journal of the Korea Institute of Building Construction
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• v.15 no.5
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• pp.465-471
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• 2015

This study proposed V-shaped tie bar method as an alternative of internal cross-tie for reinforced concrete columns in order to enhance the constructability and confinement effectiveness of the lateral tie bars. A total of 35 pull-out specimens were prepared with the parameters of concrete compressive strength and bending angle and embedment length of the V-shaped bar to examine the bond stress-slip relationship of the V-shaped tie bar. The bond strength of the V-shaped tie bars with the bending angle not exceeding $60^{\circ}$ was higher than the predictions obtained from the equations of CEB-FIP provision. Considering the constructability and bond behavior of the V-shpaed tie bar, the bending angle and embedment length of such bar can be optimally recommended as $45^{\circ}$ and 6db, respectively, where db is the diameter of the tie bar.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.191-199
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• 2005

This study was experienced in order to obtain the shear bond strength of orthodontic bracket adhesives under the blood contamination that can be occurred during the procedure of bracket bonding under window opening surgery. As a result of this study, shear bond strength of all glass ionomer groups were lower than resin cement groups. However, the strength of uncontaminated and post-contaminated group of glass ionomer was strong enough to perform an orthodontic forced eruption. This study revealed that during a window opening surgery, glass ionomer without etching procedure is available in order to bond a bracket if surface of teeth is not pre-contaminated by blood before the adhesive application. Both simple procedure and less adhesives remnant after bonding failure could make light-cured glass ionomer cement the ultimate choice for racket bonding.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.41-49
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• 2014

In order to investigation splitting bond strength of the deformed longitudinal reinforcing bars in the R C members strengthened laterally with the external steel-band, a total 9 sets of test re-bars with and without active confining force given by the external steel-band are pulled monotonically until failure. Test results indicate that the bond strength becomes higher with the increase in number of steel-band sets and their initial stress magnitude. This is due to the active confining force given by the steel-band, and passive confining forces given by the steel-band and transverse reinforcements, in which the passive confinement effect varies depending on the magnitude of active confining force. An equation to estimate the splitting bond strengths for the R C members strengthened laterally with the external steel-band is developed based on the several experimental results of the present study.