• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.187-194
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• 2023

Purpose: A mismatched size in the post and post space is a common problem during post-fixation. Since this discordance affects the bonding strength of the fiber-reinforced composite resin post (FRC Post), a corresponding luting agent is required. The aim of this study was to evaluate the bonding strength of the FRC post according to the fitness of the fiber post and the type of luting agent. Materials and Methods: Thirty mandibular premolar were endodontic-treated and assigned to two groups according to their prepared post space: Fitting (F) and Mismatching (M). These groups were further classified into three subgroups according to their luting agent: RelyX Unicem (ReX), Luxacore dual (Lux), and Duolink (Duo). A push-out test was performed to measure the push-out bond strengths. The fractured surfaces of each cross-section were then examined, and the fracture modes were classified. Results: In the ReX and Duo subgroups, the F group had a higher mean bond strength; however, the Lux subgroup had no significant difference between the F and M groups. In the analysis of the failure modes, the ReX subgroup had only adhesive failures between the cement and dentin. Conclusion: The result of this study showed that the bond strength of an FRC post was influenced by the type of luting agent and the mismatch between the diameter of the prepared post space and that of the post.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.273-278
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• 1996

The research was undertaken to characterize the reaction mode of transglucosidase (TG) from Aspergillus niger for the production of isomaltooligosaccharides such as isomaltose, panose and isomaltotriose. TG hydrolyzed maltose to glucose units and produced panose and glucose by transglucosylation. TG hydrolyzed panose to maltose and glucose when panose was used as an initial substrate. The reaction patterns of products when isomaltose, isomaltotriose or isomaltotetraose were used as substrates were different from the case when maltose was used as a substrate. Maltotriose and maltose showed the same formation pattern of products. TG also produced isomaltooligosaccharides from maltooligosaccharides. The production of panote by TG from maltose was mathematically described by Michaelis-Menten kinetics. The kinetic constants, $V_{max}$ (the maximum velocity) and $K_m$ (Michaelis constant), were estimated by Lineweaver-Burk plot to be 400 M/min and 21.4 mM, respectively.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.602-608
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• 2021

For the comparison of bond strength between the Co-Cr alloy and ceramic, which are clinically used, test samples made with a traditional casting method as a control group), and Milling and SLM(3d printing group) samples were made as an experimental group. The metal-ceramic bond strength was measured with a universal testing machine. For the measurement, a three-point bending test was conducted. After the bond strength was measured, metal-ceramic interface was observed. According to the test result, casting group had 53.59 MPa, milling group had 45.90 MPa, and 3d printing group had 58.34 MPa. There was no statistical significance. With regard to failure pattern, most of the samples in two groups, showed mixed failure. This study showed a clinically applicable value when measuring the bond strength of alloy-ceramic material with an alloy produced by 3D printing.

• Restorative Dentistry and Endodontics
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• v.33 no.2
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• pp.125-132
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• 2008

The purpose of this study is to compare the shear bond strength of repaired composite resin with different bonding agents and evaluate the effect of bonding agents on composite repair strength. Forty composite specimens (Z-250) were prepared and aged for 1 week by thermo cycling between 5 and $55^{\circ}C$ with a dwell time of 30s. After air abrasion with $50\;{\mu}m$ aluminum oxide, following different bonding agents were applied (n = 10); SB group: Scotchbond multipurpose adhesive (3 step Total-Etch system); XE group: Clearfil SE bond (2 step Self-Etch system); XP group: XP bond (2 step Total-Etch system); XE group: Xeno III (1 step Self-Etch system). After bonding procedure was completed, new composite resin (Z-250) was applied to the mold and cured. For control group. 10 specimens were prepared. Seven days after repair, shear bond strength was measured. Data was statistically analyzed using one-way ANOVA and Tukey's test (p<0.05). The means and standard deviations of shear bond strength (MPa ${\pm}$ S.D.) per group were as follows: SB group: 17.06; SE group: 19.10; XP group: 14.44; XE group: 13.57; Control Group: 19.40. No significant difference found in each group. Within the limit of this study, it was concluded that the different type of bonding system was not affect on the shear bond strength of repaired composite resin.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.239-251
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• 2006

결합조직이식을 이용한 치근피개 술식에 많은 관심이 집중되고 있다. 최근에는 acellular dermal matrix가 자가 결합조직 이식편의 대체물로써 소개되었다. 본 실험의 목적은 치근피개를 위해 acellular dermal matrix을 사용시, 그 임상 효과 빚 조직 치유 양상을 평가하고, 이를 자가 결합조직 이삭시의 결과와 비교하기 위함이다. 3마리의 성견에 인위적인 치은 퇴축부 형성을 위해서, 상악 좌우견치의 협측에서 각화치은을 모두 제거하고, 법랑백악경계부로부터 12mm 정도 치조골을 삭제한 후에 판막을 봉합하였다. 그 후 35일을 치유 기간으로 부여하였다. 총 6 부위의 결손부가 실험에 포함되었고, 각각 3 부위씩이 대조군과 실험군으로 분류되었다. 실험군에서는 acellular dermal matrix 이식과 치관측 변위 판막을 시행하였고, 대조군에서는 치은 퇴축부위에 자가 결합조직 이식과 치관측 변위 판막을 시행하였다. 치주낭 깊이, 임상적 부착 수준, 치은 퇴축 높이, 각화조직 높이 등을 인위적 결손부 형성전, 치은 피개술 시행 직전, 피개술 시행후 4주 경과시에 각각 측정하였다. 술후 4주시에, 상악 좌우 견치 부위에서 시편을 얻어 조직학적으로 관찰하고 Wilcoxon signed rank test 와 Mann-Whitney U test으로 통계처리하였다. 임상결과 관찰시, 대조군과 실험군 모두에서, 술전과 비교시 치은 퇴축 감소와 각화조직의 증가, 임상 부착수준의 개선이 나타났다.(p ( 0.05) 평균 치근 피개율은 실험군에서 61.33(5.67%(n=3), 대조군에서 55.67(5.67%(n=3) 이었고, 대조군과 실험군에서 임상결과에서는 통계학적으로 유의성 있는 차이는 없었다.(p ( 0.05). 조직학상으로는, 두 군 모두에서 이식편이 수여부에 잘 융화되어 있었고 비슷한 치유 양상을 보였다. 이상의 실험결과에 의하면, Acellular dermal matrix은 치근피개술 시행시에 결합조직 이식편의 대용품으로 사용할 수 있고 비슷한 피개 결과를 얻을수 있었다.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.165-172
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• 2019

The purpose of this study was to evaluate the effect of application time and phosphoric acid etching of 8th generation adhesives containing functional monomer on adhesive performance in primary teeth. 80 extracted non-carious human primary teeth were selected and divided into 8 groups based on 3 factors: (1) adhesive: G-Premio bond and Single bond universal; (2) application time: shortened time and manufacture's instruction; (3) acid etching mode: self-etching and total-etching. Shear bond strength was measured using a universal testing machine, and fractured surface were observed under scanning electron microscope. Microleakage was evaluated by dye penetration depth. G-Premio bond were not significant different in shear bond strength and microleakage depending on application time of adhesive and acid etching mode. In Single bond universal, shear bond strength of short application time was significantly lower than that of long adhesive application time (p = 0.014). Clinically applicable shear bond strength values (> 17 MPa) were identified in all groups. These results suggested that G-Premio bond be used clinically for a short application time without phosphoric acid etching.

• The Korean Journal of Pharmacology
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• v.23 no.2
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• pp.101-111
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• 1987

We investigated the binding properties of $(^3H)$ QNB and $(^3H)$ NMS to mAchR to elucidate the characterstics of mAchR in rat brain by using two different preparations (homogemates & intact brain cell aggregates). The binding properties of both ligands demonstrated high affinity and saturability in both experiments, however $(^3H)$ QNB showed a significantly higher maximal binding capacity than tha ot $(^3H)$ NMS 1. In rat brain homogenates; Displacement of both lignands with several mAchR antagonists resulted in competition curves in accoradnce with the law of massaction for QNB, atropine & scopolamine in thie preparation, also a similar profile was found for the quaternary ammonium analogs of atropine & scopolamine (methyl atropine & methylscopolamine) when $(^3H)$ NMS was used to label the receptors in rat brain. But when these hydrophillic antagonists were used to displace $(^3H)$ QNB, they showed interaction with high- and low-affinity binding sites in brain homogenates. Pirenzepine, the nonclassical mAchR antagonist, was able to displace both ligands from binding sites in this preparation. 2. In intact rat brain cell aggregates; Intact bain cell aggregates were used to elucidate the binding characteristics of $(^3H)$ NMS to mAchR in rat. The magnitude of binding of this ligand was related linearly to the amount of cell protein in the binding assay with a high ratio of total to nonspecific binding. mAchR antagonists displaced specific $(^3H)$ NMS binding according to the law of mass-action, while it was possible to resolve displacement curves using mAchR agonist into high-& low-affinity component. 3. Our results indicate that more hydrophilic receptor ligand $(^3H)$ QNB, displacement experiments in both tissues demonstrated that the lipid solubility of a particulr mAchR ligand might play an important role in determining its profile of binding to the mAchR, and the concentrations of mAchR in rat brain are both on the cell surface (membrane-bound receptor) and in the intracelluar membrane (intermembrane-bound receptor). 4. The results are discussed in terms of the usefulness of dissociated intact rat brain cells in studying mAchR in central nervous system.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.357-364
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• 1996

The purpose of this study was to asses the shear bond strengths of 3 types of light-curing Glass Ionomer cement to dental amalgam with or without an intermediary agent. 60 amalgam adherent specimens were prepared and aged in water at $37^{\circ}C$ for 3 days. Before bonding, the amalgam surfaces were finished flat on 600-grit silicon carbide paper. 30 specimens among 60 were used for bonding in this condition, and the other 30 were covered with a thin layer of light-curing intermediary agent. Shear bond strengths were measured with universal testing machine (Instron, Model 4301) and statistically processed by ANOVA and t-test. On completion of bond test, the fracture surfaces were examined under light microscope so that the mode of bond failure could be assessed The results were as follows : 1. Bond strength of Fuji II LC group showed the hightest value and was followed by Vitremer, Vitrebond groups (p<0.05). 2. The bond strengths achieved without an intermediary agent were higher than those obtained with intermediary agent (p<0.05). 3. For the specimens bonded with intermediary agent, bond failures occured mostly at the agent-amalgam interface. So, the use of intermediary bonding agent was thought not recommendable at glass ionomer-amalgam interface.

• Archives of design research
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• v.14 no.3
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• pp.145-154
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• 2001

These days, the products like Walkman, mobile phone, notebook PC, PDA are moving together with our body, and in the imaginary world like internet, our other self, Avatar is moving in place of our body on the cyber world. These products are related with our human body, and when considering the ones, attached to the human body, and having the meaning of mental combination like these, as the combination of the human and the products, it is necessary to examine these products in approaching them with respect to the combination relation between the human and the products. As a result of examining we can understand that the products, said to combine with the human body, are coming oui steadily. and recently, the inclination on the combination and the movement appears strongly. As this background, there are a breakdown of dichotomy thought, mixed sexual imitation, cyber culture, techno culture. concept of informative nomands, phenomenon which the division of human and machine becomes vague. and the miniaturization of products. imitation of human, phenomenon that the Inclination on the combination with human is more accelerated by networking. These products combine with human body at each wearing type in the various forms. Its functions become multi-layered, and closer to the human body physically. or its communication becomes high·graded and, they have the recombined form through the existing products which the human has And, they communicate each other. have the strong fashionable property, and the characteristics like the imaginary product to imitate the human body and substitute for the human behave.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.67-78
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• 2012

The purpose of this study was to determine whether there were differences in shear bond strength to human dentin using IDS technique compared with DDS. Forty freshly extracted human molars were and devided into 4 groups. The control group specimens were, on the morrow of tooth preparation, light-cured after application of dentin bonding agent and cemented with resin cement. The IDS/SE(immediate dentin sealing, Clearfil$^{TM}$ SE Bond) and IDS/SB (immediate dentin sealing, Adapter$^{TM}$ Single Bond 2) specimens were, on the morrow of tooth preparation, light-cured after application of dentin bonding agent(Clearfil$^{TM}$ SE Bond and Adapter$^{TM}$ Sing Bond 2, respectively), whereas DDS specimens were not treated with any dentin bonding agent. IDS/SE, IDS/SB and DDS specimens were thermocycled. Following that delay, specimens were cemented with resin cement. The dentin bonding agent was left unpolymerized until the application of porcelain restoration. Shear bond strengths were measured using a universal testing machine. Specimens also were evaluated for mode of fracture using an optical microscope. The mean shear bond strengths of control group and IDS/SE groups were not statistically different from one another. The bond strength of IDS/SE group had a significantly higher mean than that of DDS group. There was no significant difference in the mean shear bond strength between IDS/SB(4.11MPa) and DDS group. The evaluation of failure modes indicates that most failures in the control group and IDS/SE groups were mixed, whereas failures in the DDS group were interfacial. When preparing teeth for indirect ceramic restoration, IDS with Clearfil$^{TM}$ SE Bond results in improved shear bond strength compared with DDS.