• Journal of the Korean Society of Visualization
• /
• v.19 no.3
• /
• pp.123-129
• /
• 2021

Many plants and animals in nature have superhydrophobic surfaces. This superhydrophobic surface has various properties such as self-cleaning, moisture collection, and anti-icing. In this study, the superhydrophobic properties of PTFE surface were treated by plasma etching. There were four important factors that changed the surface properties. Micro-sized protrusions were formed by plasma etching. The most influential parameter was RF Power. The contact angle of the pristine PTFE surface was about 113.8°. The maximum contact angle of the surface after plasma treatment with optimized parameters was about 168.1°. In this case, the sliding angle was quite small about 1°. These properties made it possible to remove droplets easily from the surface. To verify the self-cleaning effect of the surface, graphite was used to contaminate the surface and remove it with water droplets. Graphite particles were easily removed from the optimized surface compared to the pristine surface. As a result, a surface having water repellency and self-cleaning effects could be produced with optimized plasma etching parameters.

• The korean journal of orthodontics
• /
• v.41 no.1
• /
• pp.16-24
• /
• 2011

Objective: The purpose of this study was to determine (1) the shear bond strength (SBS) of an antimicrobial monomer-containing self-etching primer according to ceramic bracket types and (2) the bracket-adhesive failure mode using an adhesive remnant index (ARI). Methods: A total of 90 extracted human teeth were randomly divided into 6 groups. Each group consisted of one of two ceramic brackets (monocrystalline, polycrystalline) and one of three primers (Transbond XT primer, Transbond Plus SEP, Clearfil Protect Bond) with each group containing 15 specimens. The SBS was measured, and adhesive residues left on the tooth surface were assessed. Results: The SBS of polycrystalline ceramic bracket groups was Significantly higher than that of the monocrystalline ceramic bracket groups (p < 0.001). The SBS of Transbond XT primer groups was significantly higher than those of Transbond Plus SEP groups and Clearfil Protect Bond groups (p < 0.001). All the groups showed bonding failures between the bracket base and adhesive. Conclusions: The combination of a self-etching primer with a monocrystalline bracket is recommended for clinical use, considering its acceptable SBS and mode of failure.

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

• Restorative Dentistry and Endodontics
• /
• v.31 no.4
• /
• pp.263-268
• /
• 2006

Recently, self-etching adhesive system has been introduced to simplify the clinical bonding proce- dures. It is less acidic compared to the phosphoric acid, thus there is doubt whether this system has enough bond strength to enamel. The purpose of this study was to investigate the influence of additional etching on the adhesion of resin composite to enamel. Ninety extracted bovine permanent anterior teeth were used. The labial surfaces of the crown were ground with 600-grit abrasive paper under wet condition. The teeth were randomly divided into six groups of 15 teeth each. Clearfil SE $Bond^{\circledR},\;Adper^{TM}$ Prompt L-Pop and Tyrian $SPE^{TM}$ were used as self-etching primers. Each self-etching primers were applied in both enamel specimens with and without additional etching. For additional etching groups, enamel surface was pretreated with 32% phosphoric acid (UNI-ETCH, Bisco, Inc., Schaumburg, IL. USA). Hybrid resin composite Clearfil AP-X, (Kuraray Co., Ltd., Osaka, Japan) was packed into the mold and light-cured for 40 seconds. Twenty-four hours after storage, the specimens were tested in shear bond strength. The data for each group were subjected to independent t - test at p < 0.01 to make comparisons among the groups. In Clearfil SE $Bond^{\circledR}$, shear bond strength of additional etching group was higher than no additional etching group (p < 0.01). In $Adper^{TM}$ Prompt L-Pop and Tyrian SPE, there were no significant difference between additional etching and non-etching groups (p > 0.01). In conclusion, self-etching adhesive system with weak acid seems to have higher bond strength to enamel with additional etching, while self-etching adhesive system with strong acid seems not.

• The korean journal of orthodontics
• /
• v.34 no.5 s.106
• /
• pp.439-447
• /
• 2004

The purpose of this study was to investigate the influence of water, saliva and blood contamination on the bonding strength of metal brackets with a self-etching primer/adhesive to enamel. Ninety-six extracted human teeth were divided into four groups. The brackets were bonded to enamel with a self- etching primer (3M/Unitek Dental Products. Monorovia California) according to one of four protocols. The teeth were bonded in a dry condition (group D) or in contamination with distilled water (group W), artificial saliva (group S). or fresh human blood (group B) Shear bond strengths were tested using an Instron Universal testing machine. After debonding. bracket and tooth surfaces were examined with a stereomicroscope. In each group, four samples were selected and examined with a Scanning electron microscope of the prepared enamel surface and resin-enamel interlace. The results obtained were summarized as follows: Shear bond Strength if group D $(15.22{\pm}2.86MPa)$ and W $(15.20{\pm}3.85 MPa)$ Were higher than in group B$(12.56{\pm}2.94MPa)$ (p<0.05). There were no statistical differences in the shear bond strengths between groups D. W and S (p>0.05). There was a tendency to have less residual adhesive remaining on the enamel surfaces of group B than group D. The SEW morphology of group D and W showed a more roughened etching pattern than group S and B. Water or saliva contamination on bending of orthodontic brackets with Transbond plus self etching primer had almost no influence on bond strength In this study, the blood contaminated group showed the lowest bond strength, but it was above the clinically acceptable bond strength (5.9-7.8 MPa, Reynold, 1975). The results of this study suggest that acceptable clinical bond strengths can be obtained in wet conditions when self-etching adhesives are used.

• International Journal of Precision Engineering and Manufacturing
• /
• v.7 no.1
• /
• pp.13-17
• /
• 2006

Self-Assembled Monolayers (SAMs) formed by alkanethiol adsorption to thin metal film are widely being investigated for applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecules and bio molecules. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAM structure formation.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.12
• /
• pp.160-166
• /
• 2004

Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated fer applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecule and bio molecule. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAMs structure formation.

• Restorative Dentistry and Endodontics
• /
• v.40 no.1
• /
• pp.68-74
• /
• 2015

Objectives: This study examined the effects of additional acid etching on the dentin bond strength of one-step self-etch adhesives with different compositions and pH. The effect of ethanol wetting on etched dentin bond strength of self-etch adhesives was also evaluated. Materials and Methods: Forty-two human permanent molars were classified into 21 groups according to the adhesive types (Clearfil SE Bond [SE, control]; G-aenial Bond [GB]; Xeno V [XV]; Beauti Bond [BB]; Adper Easy Bond [AE]; Single Bond Universal [SU]; All Bond Universal [AU]), and the dentin conditioning methods. Composite resins were placed on the dentin surfaces, and the teeth were sectioned. The microtensile bond strength was measured, and the failure mode of the fractured specimens was examined. The data were analyzed statistically using two-way ANOVA and Duncan's post hoc test. Results: In GB, XV and SE ($pH{\leq}2$), the bond strength was decreased significantly when the dentin was etched (p < 0.05). In BB, AE and SU (pH 2.4 - 2.7), additional etching did not affect the bond strength (p > 0.05). In AU (pH = 3.2), additional etching increased the bond strength significantly (p < 0.05). When adhesives were applied to the acid etched dentin with ethanol-wet bonding, the bond strength was significantly higher than that of the no ethanol-wet bonding groups, and the incidence of cohesive failure was increased. Conclusions: The effect of additional acid etching on the dentin bond strength was influenced by the pH of one-step self-etch adhesives. Ethanol wetting on etched dentin could create a stronger bonding performance of one-step self-etch adhesives for acid etched dentin.

• The korean journal of orthodontics
• /
• v.35 no.6 s.113
• /
• pp.433-442
• /
• 2005

The purpose of this study was to evaluate and compare the shear bond strength of orthodontic brackets depending on the variety of adhesives and whether saliva exists, by using self-etching primer (SEP). Groups were divided according to the type of adhesive into resin adhesive (Trans bond XT) and resin-modified glass ionomer cement (Fuji Ortho LC). One group of resin adhesive used XT primer after etching with 37% phosphoric acid, and the other group used self-etching primer. One group of resin-modified glass ionomer cement only used etching for bonding, and the other group used SEP. Each of the groups were also classified by whether saliva was contaminated or not. and then the shear bond strength was measured. The results showed that when using resin adhesive, the shear bond strength of SEP was lower than the XT primer. In the resin-modified glass ionomer cement groups, the shear bond strength which depends on the priming method, did not have a meaningful difference statistically When saliva was contaminated, the group which used SEP, regardless of the adhesive variety, had a greater shear bond strength than the normal priming group. From these results, SEP showed a shear bond strength that is possible to be used clinically, regardless of the adhesive variety. It can especially be clinically useful to use SEP to bond brackets even on tooth surfaces contaminated with saliva, because it offers the appropriate bonding strength as well as shorter treatment time and easy application.

• Restorative Dentistry and Endodontics
• /
• v.28 no.1
• /
• pp.23-33
• /
• 2003

The purpose of this study was to compare in vitro interfacial relationship of restorations bonded with three self-etching primer adhesives and one self-etching adhesive. Class I cavity preparations were prepared on twenty extracted human molars. Prepared teeth were divided into four groups and restored with four adhesives and composites Clearfil SE $Bond/Clearfil^{TM}$ AP-X (SE), UniFil $Bond/UniFil^{\circledR}$ F (UF), FL $Bond/Filtek^{TM}$ Z 250 (FL) and Prompt $L-Pop/Filtek^{TM}$ Z 250 (LP) After storing in distilled water of room temperature for 24 hours, the specimens were vertically sectioned and decalcified. Morphological patterns between the enamel/dentin and adhesives were observed under SEM. The results of this study were as follows : 1. They showed close adaptation between enamel and SE, UF and FL except for LP. 2. The hybrid layer in dentin was $2{\;}\mu\textrm{m}$ thick in SE, $1.5{\;}\mu\textrm{m}$ thick in UF, and $0.4{\;}\mu\textrm{m}$ in both FL and LP. So, the hybrid layers of SE and UF were slightly thicker than that of FL and LP. 3. The lengths and diameters of resin tags in UF and FL were similar, but those of LP were slightly shorter and slenderer than those of SE. 4. The resin tags were long rod shape in SE, and funnel shape in other groups Within the limitations of this study, it was concluded that self-etching primer adhesives showed close adaptation on enamel. In addition, the thickness of hybrid layer ranged from $0.4-1.5{\;}\mu\textrm{m}$ between adhesives and dentin. The resin tags were long rod or funnel shape, and dimension of them was similar or different among adhesives.