• 한국세라믹학회지
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• 제31권9호
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• pp.941-948
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• 1994

An underwater grout on material resistance against segregation in water were studied by water soluble polymer (methyl cellulose and acrylic acid ester and styrene). The mechanical properties of the grout agents were investigated through the observation of the microstructure and application of fracture mechanic. When the soluble polymer MC+AAES added with 0.6 wt% to the underwater grout agents the compressive strength, flexural strength and Young's modulus were about 58 MPa, 10 MPa and 3.2 GPa respectively, and critical stress intensity was about 0.8 MNm-1.5. It can be considered that the strength improvement and fracture toughness increase may be due to the pore decrease and bonding force by material resistance against segregation in water.

• Macromolecular Research
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• 제10권1호
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• pp.24-33
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• 2002

Interfacial and microfailure properties of carbon fiber/epoxy composites were evaluated using both tensile fragmentation and compressive Broutman tests. A monomeric and two polymeric coupling agents were applied via the electrodeposition (ED) and the dipping applications. A monomeric and a polymeric coupling agent showed significant and comparable improvements in interfacial shear strength (IFSS) compared to the untreated case under both tensile and compressive tests. Typical microfailure modes including cone-shaped fiber break, matrix cracking, and partial interlayer failure were observed under tension, whereas the diagonal slipped failure at both ends of the fractured fiber appeared under compression. Adsorption and shear displacement mechanisms at the interface were described in terms of electrical attraction and primary and secondary bonding forces.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.605-605
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• 2003

Novel silane coupling agents containing hydrophobic phenyl group 3-(3-methoxy-4-methacryloyloxyphenyl) propyl-trimethoxysilane(p-MPS), -triisocyanatesilane (p-MBI), -trichlorosilane (p-MBC) were synthesized. The bonding durability of these silanes against water immersion and thermal stress was investigated. 3-methacryloyloxypropyltrimethoxysilane (3-MPG) was used as a control. The glass modified with those silanes at a concentration of 2wt％ were kept for 3 minutes at $120^{\circ}C$, and then were bonded to the heaped metal with self-cured resin composite.(omitted)

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.576.2-576
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• 2001

The purpose of this study was to evaluate the effect of dentinal sclerosis and tubular orientation on Class V restoration bonded with three dentin bonding agents using confocal laser scanning microscope(CLSM). Class V cavities were prepared from freshly extracted caries-free human teeth. thirty of these cavities were divided into two groups based upon the status of class V cavities: Group 1, cervical abrasive lesions without preparation; Group 2, artificially-prepared wedge-shaped cavities.(omitted)

• 대한소아치과학회지
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• 제49권3호
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• pp.264-273
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• 2022

치과에서 사용하는 재료들의 물성의 발달로 인하여 브라켓과 치아 사이의 결합 능력도 크게 향상되었다. 그러나 소아치과 영역에서와 같이 환자의 협조를 기대하기 어렵거나, 수분 격리가 제대로 이루어지지 않을 경우 기대하는 효과에 미치지 못하는 결합강도를 보여 줄 수 있다. 본 연구의 목적은 세 가지의 접착 술식을 비교하여 브라켓의 전단 접착 강도를 평가하고, 임상적으로 유의한 차이가 존재하는지 비교하는 것이다. 우식증이나 수복물이 없는 상, 하악 소구치 60개 치아를 대상으로 하였다. Group I은 대조군으로서 기존의 3 step 접착 방식에 따라 브라켓을 부착하였고, Group II는 self-etching primer system을 이용하여 부착하였다. Group III는 self-priming adhesive를 이용하여 브라켓을 부착하였다. 각 group의 전단 결합 강도를 측정하고 접착제 잔류지수(ARI)를 기록하였다. 각 group I, II, III의 평균 전단 결합 강도는 14.69 MPa, 11.21 MPa 그리고 12.21 MPa로 측정되었다. Group I과 II, group I과 III에서만 유의한 차이가 존재하였으며(p < 0.05), ARI 값은 모든 group에서 유의한 차이가 존재하지 않았다.

• 멤브레인
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• 제10권3호
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• pp.148-154
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• 2000

본 연구에서는 sulfur-succinic acid의 가교제를 이용한 가교된 폴리비닐알코올(poly(vinyl alcohol), PVA) 가교막을 이용하여 MTBE-methanol 혼합액에 대하여 조업온도, 가교제의 조성에 따른 증기투과 공정의 투과 특성을 조사 하였다. 팽윤 실험을 통해 PVA/SSA 가교막에 대하여 가교제 조성에 따른 막의 구조와 PVA의 하이드록실기(-OH), SSA의 설폰기(-$SO_3$H)와 용매와의 수소결합의 두 가지 인자가 상호 보완적으로 작용하고 있음을 알 수 있었다. 투과 특성에 있어 SSA의 설폰기가 중요한 인자로 작용하였다. 예를 들면 7% SSA 막에 대해서는 수소결합의 효과보다는 가교도의 효과가 투과 특성에 중요한 요인으로 작용하며 5% SSA에 대해서는 수소결합의 효과가 중요하게 작용하였다. 증기투과 공정에 있어 막과 직접 접촉하는 증기상이 액상에 비하여 methanol의 농도가 낮아 PVA의 하이드록실기와 methanol과의 수소결합 확률이 감소함에 따라 투과 특성에 영향을 미친다. 결과적으로 7% SSA 막에 대하여 MTBE/mthanol=80/20 혼합액에 대하여 공급액의 온도 3$0^{\circ}C$에서 선택도 2187, 투과도 4.84g/$m^2$hr를 보여 주었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3310-3312
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• 1999

We have studied the method of silicon direct bonding using the mixture of $HNO_$, $H_2O_2$, and HF chemicals called the controlled slight etch (CSE) solution for the effective wafer cleaning. CSE, two combinations of oxidizing and etching agents, have been used to clean the silicon surfaces prior to wafer bonding. Two wafers of silicon and silicon dioxide were contacted each other at room temperature and postannealed at $300{\sim}1100^{\circ}C$ in $N_2$ ambient for 2.5 h. We have cleaned silicon wafers with the various HF concentrations and characterized the parameters with regard to surface roughness, chemical nature, chemical oxide thickness, and bonding energy. It was observed that the chemical oxide thickness on silicon wafer decreased with increasing HF concentrations. The initial interfacial energy and final energy postannealed at $1100^{\circ}C$ for 2.5h measured by the crack propagation method was 122 $mJ/m^2$ and 2.96 $mJ/m^2$, respectively.

• Restorative Dentistry and Endodontics
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• 제21권2호
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• pp.585-601
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• 1996

The purpose of this study was to elucidate the effect of blood-and saliva-contamination during dentin pretreatment procedure on tensile bond strength, and to investigate the effect of contaminant-removing treatments on the recovery of bond strength of dentin bonding agents. Dentin specimens prepared from freshly extracted bovine mandibular anterior teeth were divided into non-contaminated control and contaminated experimental groups. The specimens of the contaminated group were contaminated with saliva or blood after etching or priming procedure, followed by contaminant-removing treatments. All the specimens were bonded with All Bond$^{(R)}$ 2 dentin bonding agent and Bisfil$^{TM}$ composite resin or Scotchbond$^{TM}$ Multipurpose and Z100. After all the bonded specimens were stored in $37^{\circ}C$ distilled water for 24 hours, tensile bond strengths were measured. The contaminated dentin and fractured dentin surfaces were examined under the scanning electron microscope. The results were as follows : Contaminated specimens showed lower bond strength than non-contaminated ones regardless of the kind of contaminant, contamination time and contaminant-removing treatments, except specimens which were acid-etched following saliva contamination after etching in All Bond$^{(R)}$ 2 groups (p<0.05). Blood contaminant resulted in much bond strength decrease than saliva ones (p<0.01), and contamination after priming resulted in much decrease in bond strength than after etching (p<0.01). Re-etching resulted in increase of bond strength in the specimens contaminated with saliva after etching but not in blood contaminated ones. Re-priming resulted in increase of bond strength in the specimens contaminated after priming regardless of the kind of contaminant.

• Restorative Dentistry and Endodontics
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• 제39권4호
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• pp.303-309
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• 2014

Objectives: Hydrogen peroxide ($H_2O_2$) surface treatment of fiber posts has been reported to increase bond strength of fiber posts to resin cements. However, residual oxygen radicals might jeopardize the bonding procedure. This study examined the effect of three antioxidant agents on the bond strength of fiber posts to conventional and self-adhesive resin cements. Materials and Methods: Post spaces were prepared in forty human maxillary second premolars. Posts were divided into five groups of 8 each: G1 (control), no pre-treatment; G2, 10% $H_2O_2$ pre-treatment; G3, G4 and G5. After $H_2O_2$ application, Hesperidin (HES), Sodium Ascorbate (SA) or Rosmarinic acid (RA) was applied on each group respectively. In each group four posts were cemented with Duo-Link conventional resin cement and the others with self-adhesive BisCem cement. Push-out test was performed and data were analyzed using 2-way ANOVA and tukey's post-hoc test (${\alpha}=0.05$). Results: There was a statistically significant interaction between the cement type and post surface treatment on push-out bond strength of fiber posts (p < 0.001, F = 16). Also it was shown that different posts' surface treatments significantly affect the push-out bond strength of fiber posts (p = 0.001). $H_2O_2$ treated posts (G2) and control posts (G1) cemented with Duo-link showed the highest ($15.96{\pm}5.07MPa$) and lowest bond strengths ($6.79{\pm}3.94$) respectively. Conclusions: It was concluded that $H_2O_2$ surface treatment might enhance the bond strength of fiber posts cemented with conventional resin cements. The effect of antioxidants as post's surface treatment agents depends on the characteristics of resin cements used for bonding procedure.

• Restorative Dentistry and Endodontics
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• 제46권4호
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• pp.55.1-55.9
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• 2021

Objectives: The purpose of this systematic review was to collect and discuss the technique of adhesive systems application on dentin substrate under electric current. Materials and Methods: The first search strategy was based on data available at PubMed, LILACS, Scielo, Scopus, and Cochrane Library, using a combination of descriptors such as "dentin bond agents OR adhesive system AND electric current OR electrobond" or "dentin bonding agents OR dentin bonding agent application OR adhesive system AND electric current OR electrobond", with no limit regarding the publication year. The second search strategy was based on the articles' references found previously. An additional search strategy was applied that concerned the proposed theme in the SBU-UNICAMP (Unicamp's Library System Institutional Repository). Results: Twelve studies published between 2006 and 2020 were found. The analyses of the selected studies showed that the use of electric current during adhesive systems application on dentin, whether conventional or self-conditioning, increases resinous monomer infiltration in the dentin substrate, which improves the hybridization processes and the bond strength of the restorative material to dentin. Conclusions: Despite the favorable results related to the use of this technique, there is still no specific protocol for the application of adhesive systems under electric current.