• The korean journal of orthodontics
• /
• v.27 no.5 s.64
• /
• pp.771-779
• /
• 1997

The purpose of this in vitro study was to evaluate the effects of different acid etching times on the enamel surface morphology, shear bond strength and debonding failure mode of orthodontic attachment. Ninety six extracted human mandibular premolars were divided into eight groups of twelve teeth. The buccal surfaces were etched with $37\%$, phosphoric acid for 5, 10, 15, 30, 45, 60, 90 and 120 seconds, respectively. Two teeth from each group were used for scanning electron microscope examination. On the etched buccal surfaces of remaining teeth, orthodontic attachments(lingual buttons) were bonded with light cured orthodontic adhesive. Twenty foot hours after bonding, a Instron universal testing machine was used to determine shear bond strength of orthodontic attachment to enamel. After debonding, bases of orthodontic attachments and enamel surfaces were examined under stereoscopic microscope to determine failure mode. Statistical analysis of the data was carried out with one nay ANOVA and Duncan's multiple range test The results were as follows; 1. There was no statistically significant difference in shear bond strengths between the various etching times(p<0.05). 2. The failure modes of orthodontic attachments had some differences. In 5, 10 and 15 seconds etching groups, the percentage of adhesive/enamel interface failure was higher than that of adhesive/attachment interface failure. On the contrary, in 30, 45, 60, 90 and 120 seconds etching groups, the results were reversed. 3. The etching patterns of enamel surfaces had a great variation. So, we could not find any correlation between etching pattern and bond strength. 4. The findings in this study indicate that in vitro reduction of the etching me to 5 seconds maintains clinically acceptable bond strength. However, further study is required to determine the cause of failure mode in 5, 10 and 15 seconds groups.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.4
• /
• pp.445-452
• /
• 2010

Recently the effect of CPP-ACP on early caries remineralization and prevention has hashbeen extensively researched. However, there has been a lack of research on micro-shear bond strength of a sealant applied on a CPP-ACP treated surface. Therefore, the purpose of this study was to evaluate the effect of CPP-ACP on the micro-shear bond strength of a sealant bonded with 3 different bonding systems. From the sound human 3rd molars, the 150 specimens were prepared and randomly assigned to six groups. Group I: Immersion in artificial saliva for 2 weeks + 35% phosphoric acid Group II: Immersion in artificial saliva for 2 weeks + 35% phosphoric acid + dentin bonding agent Group III: Immersion in artificial saliva for 2 weeks + self-etching adhesive Group IV: CPP-ACP application for 2 weeks + 35% phosphoric acid Group V: CPP-ACP application for 2 weeks + 35% phosphoric acid + dentin bonding agent Group VI: CPP-ACP application for 2 weeks + self-etching adhesive Sealant was applied and the micro-shear bond strength was measured. From the result of this study, it can be assumed that the CPP-ACP pretreatment can weaken the bond strength of a sealant if the enamel surface is conditioned with self-etch adhesive.

• Elastomers and Composites
• /
• v.23 no.1
• /
• pp.53-68
• /
• 1988

• Elastomers and Composites
• /
• v.23 no.2
• /
• pp.174-185
• /
• 1988

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.4
• /
• pp.636-644
• /
• 2004

Recently, self-etching adhesive system have been developed and bonding procedures simplified into one or two steps, which are simultaneously applied to both enamel and dentin. These systems are easy to use and have the potential for good clinical success. The purpose of this study is to evaluate in vitro the microleakage on the cementum/dentin and enamel walls in composite resin restoration of Class V cavities, regarding the use of different adhesive systems. 30 human premolars were divided into 3 groups. A standardized Class V preparation was prepared on the buccal and lingual surface of each premolar. The preparation were made parallel to the cementoenamel junctions, with the gingival half of the preparation extending 1mm apical to the cementoenamel junction. After adhesive system was applied to teeth as manufacture's recommendation, hybrid resin composite was filled in bulk into the preparation and light polymerized according to manufacturer's recommendations. Specimen were stored in distilled water at $37^{\circ}C$ for 5 days and thermocycled 1000 times ($5^{\circ}C{\pm}2^{\circ}C\;and\;55^{\circ}C{\pm}2^{\circ}C)$, then immersed in a 2% methylene blue solution for 12 hours. After sectioning mesio distally through the restorations, the degree of dye penetration was scored under a stereomicroscope at ${\times}\;25$ magnification. The data were analyzed statistically using t-test and one-way ANOVA. The results were as follows: ${\cdot}$ There is no adhesive system which can prevent microleakage perfectly. ${\cdot}$ There is significant difference in microleakage between enamel margin and dentin margin (p<0.0001). ${\cdot}$ In enamel margin, self-etching primer systems did not show any significant difference comparing total-etching system. In denin margin, self-etching primer systems did not show any significant difference comparing one-bottle adhesive system used in combination with total-etching.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.44 no.3
• /
• pp.358-364
• /
• 2017

For the purpose of convenience and reducing time, newer bonding agents have been developed for composite resin restoration. Recently developed one bottle bonding system including etching, primer and adhesive can make procedures simpler and less technique-sensitive than old generation adhesives. The aim of this study was comparing the shear bond strength of new dentin bonding agents to the 5th generation bonding agent which had an etching step. 78 premolar teeth were randomly divided into three groups which were treated with $Tetric^{(R)}$ N-Bond Universal (Ivoclar Vivadent, Liechtenstein), $GC^{(R)}$ G-Premio BOND (GC Co., Japan) without additional etching step and $3M^{TM}$ Single Bond2 (3M ESPE, USA) with an etching step following manufacturer's instructions. $Filtek^{TM}$ Z-350 (3M ESPE, USA) composite resin was applied and light cured over bonding agents. For shear bond strength evaluation, universal testing machine was used with a wedge technique. As a result, shear bond strength of one step bonding agents was lower than two step bonding agent and there were statistically significant differences between them (p < 0.05). In addition, within the result of two new bonding agents, $Tetric^{(R)}$ N-Bond Universal showed significantly higher shear bond strength than $GC^{(R)}$ G-Premio BOND (p < 0.05).

• Restorative Dentistry and Endodontics
• /
• v.32 no.4
• /
• pp.365-376
• /
• 2007

The purpose of this study was to evaluate the effect of different etching times on microtensile bond strength (${\mu}TBS$) to dentin both initial and after thermocycling with 3 different types of total-etching adhesives. Fifty four teeth were divided into 18 groups by etching times (5, 15, 25 sec), adhesives types (Scotchbond Multipurpose (SM), Single Bond (SB), One-Step (OS)) and number of thermocycling (0, 2,000 cycles). Flat dentin surfaces were prepared on mid-coronal dentin of extracted third molars. After exposed fresh dentin surfaces were polished with 600-grit SiC papers, each specimen was acid-etched with 35% phosphoric acid (5, 15, 25 sec) and bonded with 3 different types of total etching adhesives respectively. Then, hybrid composite Z-250 was built up. Half of them were not thermocycled (control group) and the ethers were subjected to 2,000 thermocycle (experimental group). They were sectioned occluso-gingivally into $1.0\;{\times}\;1.0\;mm^2$ composite-dentin beams and tested with universal testing machine at a crosshead speed of 1.0 mm/min. Within limited data of this study, the results were as follows 1. There was no statistically significant difference in ${\mu}TBS$ between the thermocycled and non-thermocycled groups, except for both SM and SB etched for 25 sec. 2. In thermocycled SM and SB groups, bond strength decreased by extended etching time. In total etching systems, adhesive durability for dentin could be affected by type of solvents in adhesive and etching time. Especially, extended etching time may cause deteriorate effects on bond strength when ethanol-based adhesive was used.

• International Journal of Highway Engineering
• /
• v.4 no.3 s.13
• /
• pp.15-23
• /
• 2002

The waterproofing system's performance is known to show a determing by complex interaction of material factors, design details, and the quality of construction, and the waterproofing integrity of waterproofing membranes is determined by the bond to the deck and the amount of damage to the waterproofing membrane. In this research, the basic properties of waterproofing membranes on market and the tensile adhesive chracteristics of waterproofing systems of concrete bridge deck have also been investigated in the view of the damages frequently reported from job site. For the tensile adhesive strength of sheet waterproofing membranes, the results after asphalt concrete paving tends to increase more than before those. The results of the liquid waterproofing membranes are upside-down, and the more concrete has strength, the more strength of tensile adhesive increase. The ambient temperature of asphalt concrete when application of the waterproofing membrane has considerable influence on the performance of waterproofing system. As described above, waterproofing system can be influenced by several factors. If they are not considered under construction, the overlooking will cause the damages of pavement and waterproofing system after traffic opening.

• Composites Research
• /
• v.34 no.5
• /
• pp.323-329
• /
• 2021

In this paper, the characteristics of fracture in mode I loading were analyzed for adhesively bonded joints with non-uniform adhesion. The Double Cantilever Beam test was performed and mode I fracture toughness was obtained. In the case of non-uniform adhesively bonded joints, the stable crack growth sections and unstable crack growth section were shown. The fracture characteristics of each section were observed through the load-displacement curve of the DCB test and the fracture surface of the specimen. Finite Element Analysis was performed at the section based on segmented section by crack length measured through the test and using the mode I fracture toughness of each section. Through DCB test results and finite element analysis results, it was confirmed that the fracture behavior of specimens with non-uniform adhesion can be simulated.

• Restorative Dentistry and Endodontics
• /
• v.32 no.5
• /
• pp.426-436
• /
• 2007

The objective of this study is to evaluate the effect of an additional application of bonding resin on the bond strength of resin luting cements in both the light-cure (LC) and self-cure (SC) modes by means of the ${\mu}TBS$ tests. Three combinations of One-Step Plus with Choice, Single Bond with Rely X ARC, and One-Up Bond F with Bistite II were used. D/E resin and Pre-Bond resin were used for the additional application. Twelve experimental groups were made. Three mandibular $3^{rd}$ molars were used in each group. Indirect composite blocks were cemented on the tooth surface. $1\;{\times}\;1\;mm^2$ dentin-composite beam for ${\mu}TBS$ testing were made and tested. When total-etching dentin adhesives were used, an additional application of the bonding resin increased the bond strength (P < 0.05). However, this additional application didn't influence the bond strength of self-etching dentin adhesives (P > 0.05). In conclusion, the results suggest that an additional application of the bonding resin increases bond strength and enhances quality of bonding when using total-etching dentin adhesives.