• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3313-3315
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• 1999

Si direct bonding(SDB) technology is very attractive for both Si-on-insulator(SOI) electric devices and MEMS applications because of its stress free structure and stability. This paper presents on pre-bonding according to HF pre-treatment conditions in Si wafer direct bonding. The characteristics of bonded sample were measured under different bonding conditions of HF concentration, and applied pressure. The bonding strength was evaluated by tensile strength method. The bonded interface and the void were analyzed by using SEM and IR camera respectively. A bond characteristic on the interface was analyzed by using IT- IR. Si-F bonds on Si surface after HF pre-treatment are replaced by Si-OH during a DI water rinse. Consequently, hydrophobic wafer was bonded by hydrogen bonding of Si $OH{\cdots}(HOH{\cdots}HOH{\cdots}HOH){\cdots}OH-Si$. The bond strength depends on the HF pre-treatment condition before pre- bonding (Min:$2.4kgf/crn^2{\sim}Max:14.9kgf/crn^2$)

• Journal of dental hygiene science
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• v.11 no.5
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• pp.397-404
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• 2011

The aims of this study were to evaluate the effect of native acidity upon dental hard tissues by measuring pH in mouth-rinse, which is on the market, and to evaluate even influence of dental stain caused by mouse-rinse given using for a long time. The experimental group was used Garglin, Nextcare, Listerine, and Hexamedin. The control group was used sterile distilled water. As a result, pH was indicated to be low in Nextcare(4.70) and Listerine(4.16). In a change of color tone, $b^*$ value of indicating Yellow-blue showed the lower value than the early color tone in all groups. There was statistical significance in Nextcare and Listerine. ${\Delta}L^*$ value of indicating light -dark gets darker after using Nextcare, Listerine and Hexamedine. A change(VHN) in surface hardness of enamel showed reduction in surface hardness after 14 days in Nexcare and Listerine. As a result of confirming a change in enamel surface by using Scanning Electron Microscopy, the erosion aspect on the enamel surface could be confirmed in groups of Nexcare and Listerine. Ra value in surface roughness of enamel could be observed the enamel surface, which got rougher compared to other experimental groups.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.169-175
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• 2003

For safe and easy disposal of prochloraz wastewaters after used as rice seed disinfectant in Korean farms, this experiment was carried out. By addition of several agricultural materials commonly utilizing in farmers, removal effect of prochloraz from waste solution was also investigated. When rice seeds after soaking in diluted prochloraz solution were rinsed with water several times, prochloraz was removed $9.2\sim10.6%$ at the first rinse and less than 3 % at the fourth rinse. A half life of prochloraz was $4\sim5$ days in aqueous system. Hydrolysis of prochloraz was more rapidly in alkali solution than neutral and acidic one at $25^{\circ}C$ and $35^{\circ}C$. By the irradiation under $5530J/cm^2$ using xenone lamp, prochloraz was photo-degraded to 87.7% in aqueous system. The removal efficiency of prochloraz by addition of several agricultural materials were as follows: 93.6% by lime, 90.7% by composed pig manure, 89.4% by activated charcoal, 78.0% by straw ash, 70.3% by sandy loam soil, 47.0% by zeolite and 24.1 % by rice straw. When prochloraz solution was sprayed on the field soil, it was dissipated upto 90% within 35 days.

• Journal of Sensor Science and Technology
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• v.9 no.2
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• pp.134-140
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• 2000

Si wafer direct bonding(SDB) technology is very attractive for both Si-on-insulator(SOI) electronic devices and MEMS applications. This paper presents on pre-bonding according to HF pre-treatment conditions in Si wafer direct bonding. The characteristics of bonded sample were measured under different bonding conditions of HF concentration and applied pressure. The bonding strength was evaluated by tensile strength method. A bond characteristic on the interface was analyzed by using FT-IR, and surface roughness according to HF concentration was analyzed by AFM. Si-F bonds on Si surface after HF pre-treatment are replaced by Si-OH during a DI water rinse. Consequently, hydrophobic wafer was bonded by hydrogen bonding of Si-OH$\cdots$(HOH$\cdots$HOH$\cdots$HOH)$\cdots$OH-Si. The pre-bonding strength depends on the HF pre-treatment condition before pre-bonding. (Min : $2.4kgf/cm^2{\sim}$Max : $14.9kgf/cm^2$)

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.372-380
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• 2008

Purpose: The purpose of this study was to evaluate the effect of various methods of dentin bonding agent application on microtensile bond strength between dentin and resin, using a 2-step etch-and-rinse dentin bonding agent. Material and methods: Twenty freshly extracted human molars were obtained and divided into 4 groups of 5 teeth. 2-step etch-and-rinse dentin bonding agent was used for all groups. The control specimens were prepared using a direct immediate bonding technique. The delayed dentin sealing (A, C) specimens were prepared using an indirect approach with delayed dentin sealing. For group A, resin was built-up on uncured dentin bonding agent, and for group C, resin was built-up on pre-cured dentin bonding agent. Preparation of the immediate dentin sealing (B) specimens also used an indirect approach with immediate dentin sealing immediately following preparation. All teeth were prepared for a microtensile bond strength test. Specimens were stored in water for 24 hours. Ten beams (1.0 ${\times}$ 1.0 ${\times}$ 11 mm) from each tooth were selected for testing. Bond strength data (MPa) were analyzed with a one-way ANOVA test, and post hoc comparison was done using the Scheffe's test. Results: The mean microtensile bond strengths of control group, B and C (DDS with pre-cure) were not statisticaaly different from each other at 32.7, 33.3, 34.2 MPa. the bond strength for group A (DDS without pre-cure), 19.5 MPa, was statistically different (P < .01) from the other 3 groups. Conclusion: When preparing teeth for indirect bonded restorations, DDS with pre-curing dentin bonding agent and IDS results in the same bond strength between dentin and resin. On the contrast, the bond strength was decreased when DDS without pre-curing dentin bonding agent was used.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.262-274
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• 1999

Several alternatives for increasing the fluoride concentration in the mouth, such as water fluoridation, ingestion of fluoride supplements, fluoride paste, fluoride mouthrinse, application of fluoride gel are available. There is an impressive body of evidence that the topically deliverd fluorides are clinically effective in inhibiting the progression of dental caries. Recent studies on the cariostatic action of fluoride have indicated the importance of fluoride in the fluid environment of the teeth. The fluoride levels in unstimulated whole saliva can be considered indicative of F in the aqueous phase available for interaction with the tooth surface at a given time. The retention of F in the mouth after topical fluoride treatment is considered to be an important factor in the clinical efficacy of F. The aim of this study was to determine the elevation and clearance of fluoride in whole saliv after the following topical flouride treatments using HMDS-diffusion technique and fluoride ion electrode. The obtained results were as follow: 1. Average salivary fluoride concentration in the unstimulated whole saliva was $0.0152ppm{\pm}0.0091ppm$. Unstimulated salivary flow rate was between 0.34-0.36ml/min and there was no statistically significant difference among the groups(p>0.05). 2. Except for the immediate time after treatment, fluoride levels followed as APF gel>neutral gel>F-rinse>F-paste. There was no statistical difference between the salivary F concentration of F-paste group and that of control group after 2 hours. In case of F-rinse group, after 3 hours the concentration had dropped to baseline value. But there was statistically significant difference among the F concentraion of F gel groups and that of control group(p<0.05). 3. The mean $AUC_{0-120min}$ values were followed as neutral gel>APF gel>F-rinse>F-paste, and the values of the two former groups were significantly higher than those of the two latter groups(p<0.05).

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.192-198
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• 2007

Kimchi is one of the representative traditional foods in Korea, which is recognized as a kind of wellbeing foodstuffs. However, as increasing foreign-made Kimchi, its safety as food is at the forefront of public health concerns. We analyzed the washing methods of Chinese cabbages, which are the main materials in Kimchi, to prevent parasite contamination during preparing it. To decontaminate parasite eggs from Chinese cabbages, discard the discolored outer leaves from cabbages, spread the space of leaves with fingers and rinse more than 3 separate water tanks with streaming water (velocity more than 0.8m/sec). At each tank, Chinese cabbages were rinsed with more than 3 strokes upward and downward within the streaming water followed by moving back and forth more than 3 times, with 20cm in height and 30cm in width, respectively. Decontamination efficiency increased higher in parallel with streaming velocity of water, and with adding the vegetable detergent to the tank water.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.148-156
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• 2008

Statement of problems: Self-etch adhesives exhibit some clinical benefits such as ease of manipulation and reduced technique-sensitivity. Nevertheless, some concern remains regarding the bonding effectiveness of self-etch adhesives to enamel, in particular when so-called 'mild' self-etch adhesives are employed. This study compared the microtensile bond strengths to ground enamel of the two-step self-etch adhesive Clearfil SE Bond (Kuraray) to the three-step etch-and- rinse adhesive Scotchbond Multi-Purpose (3M ESPE) and the one-step self-etch adhesive iBond (Heraeus Kulzer). Purpose: The purpose of this study was to determine the effect of a preceding phosphoric acid conditioning step on the bonding effectiveness of a two-step self-etch adhesive to ground enamel. Material and methods: The two-step self-etch adhesive Clearfil SE Bond non-etch group, Clearfil SE Bond etch group with prior 35% phosphoric acid etching, and the one-step self-etch adhesive iBond group were used as experimental groups. The three-step etch-and-rinse adhesive Scotchbond Multi-Purpose was used as a control group. The facial surfaces of bovine incisors were divided in four equal parts cruciformly, and randomly distributed into each group. The facial surface of each incisor was ground with 800-grit silicon carbide paper. Each adhesive group was applied according to the manufacturer's instructions to ground enamel, after which the surface was built up using Light-Core (Bisco). After storage in distilled water at $37^{\circ}C$ for 1 week, the restored teeth were sectioned into enamel beams approximately 0.8*0.8mm in cross section using a low speed precision diamond saw (TOPMET Metsaw-LS). After storage in distilled water at $37^{\circ}C$ for 1 month, 3 months, microtensile bond strength evaluations were performed using microspecimens. The microtensile bond strength (MPa) was derived by dividing the imposed force (N) at time of fracture by the bond area ($mm^2$). The mode of failure at the interface was determined with a microscope (Microscope-B nocular, Nikon). The data of microtensile bond strength were statistically analyzed using a one-way ANOVA, followed by Least Significant Difference Post Hoc Test at a significance level of 5%. Results: The mean microtensile bond strength after 1 month of storage showed no statistically significant difference between all adhesive groups (P>0.05). After 3 months of storage, adhesion to ground enamel of iBond was not significantly different from Clearfil SE Bond etch (P>>0.05), while Clearfil SE Bond non-etch and Scotchbond Multi-Purpose demonstrated significantly lower bond strengths (P<0.05), with no significant differences between the two adhesives. Conclusion: In this study the microtensile bond strength to ground enamel of two-step self-etch adhesive Clearfil SE Bond was not significantly different from three-step etch-and-rinse adhesive Scotchbond Multi-Purpose, and prior etching with 35% phosphoric acid significantly increased the bonding effectiveness of Clearfil SE Bond to enamel at 3 months.

• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.656-669
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• 1998

Hydrogen peroxide at high concentration during walking bleaching may cause damage to the tooth structure and to the surrounding periodontal tissues and may develop external root resorption. Clinically, It is so important to find a method of prevention or minimization of these complications. The efficacy of various chamber-irrigating agents to eliminate residual hydrogen peroxide after walking bleaching was examined and compared with water rinse in this study. Extracted human 46 premolars without any cementoenamel junction defects were treated endodontically and based with IRM to 1 mm below CEJ and totally bleached 3 times for each tooth with 30% hydrogen peroxide and sodium perborate. Upon completion of the 3rd walking bleaching procedure, the cervical portion and pulp chamber of each group of teeth were irrigated with catalase, 70% ethylalcohol, acetone, and distilled water. And then, a radicular hydrogen peroxide penetration was measured with spectrophotometer immediately after each bleaching and following treatment with each chamber-irrigating agents, and the significance of their eliminating efficacy of residual hydrogen peroxide was analyzed by Kruskal-Wallis test. The results were obtained as follows. 1. Cervical root penetration of hydrogen peroxide was increased as the bleaching procedure was repeated(P<.01). 2. The most effective irrigant that removed residual hydrogen peroxide was the catalase, and the least effective one was water rinsing (P<.01).; there was no significant difference between the acetone and ethanol group. 3. The Irrigation with antioxidant enzyme or water-displacement solutions can eliminate residual oxygen radicals from the pulp chamber effectively after walking bleaching. So, these agents can reduce adverse effects such as cervical external resorption and periapical inflammation and prevent residual $O_2$ from impeding composite resin polymerization, thus increase the bonding strength of composite resin. This, in turn reduces microleakage and discoloration of the esthetic restoration, extending its service-life.

• Journal of Oral Medicine and Pain
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• v.32 no.2
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• pp.151-156
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• 2007

Antimicrobial action of phytoncide in the mouth decrease odor-producing microorganisms. Also phytoncide has malodor effect by reaction with volatile sulfur compounds. Phytoncide has excellent malodor effect in microbiologically and chemically. This study prove the malodor effect of phytoncide by use ferrous sulfate. So I try to make new treatment method for halitosis. I get the results as follows. 1. The difference of mean value of absorbancy was 0.849 between the mean absorbancy of deposition by add phytoncide to saliva and the saliva only. 2. The difference of mean value of absorbancy was 0.701 between the mean absorbancy of deposition by add phytoncide to distilled water and the distilled water only. 3. The difference of mean value(0.849) in saliva by existence of phytoncide was larger than in double distilled water(0.701) by existence of phytoncide. Therefore, phytoncide make more deposition in saliva than double distilled water by reaction with sulfur compounds. As the results, phytoncide reaction with sulfur compounds in saliva. It take malodor action in liquid state effectively. It is thought, only the toothpaste it knows from in the limit which does not have a side effect by the human body it adds in the oral cavity of the mouth rinse and with the fact that it will be able to use positively in clinic.