• Membrane Journal
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• v.8 no.2
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• pp.77-85
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• 1998

To treat effectively EDIR (electrodeposition ion removal) wastewater in terms of CO$_{Mn}$ 1,500~2,000 ppm generated from aluminum painting process, a RO (reverse osmosis) process was designed and installed to recover and reuse the concentrated solvent sent back to the electrocodeposition tank while the permeate reused as rinse water. A RO system in which three polyamide-spiral wound modules ($102\Phi \times 1,016L$ mm) connnected in series had been running to treat 20 m$^3$ in waste volume in 3 days batch operation at the condition of system recovery of 30 %, applied pressure 11.5 $kg_f/cm^2$ and room temperature. During 42 hours continuous operation leading to 5-fold decrease in waste volume, nearly constant permeation flux of 390 l/m$^2$-hr was maintained and the permeate with average CO$_{Mn}$, 300 ppm was obtained which could be used for washing the remaining paint solution in ion-exchange tower instead of demineralized water. Also COD$_{Mn}$ rejection as a function of running time was observed to be in the range of 78~87 % and the observed solvent rejections for ethyl cellusolve, buthyl cellusolve and n-butanol were 79 %, 87 % and 70 %, respectively.

• Journal of Oral Medicine and Pain
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• v.36 no.4
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• pp.245-252
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• 2011

The aim of this study is to clinically evaluate the effect of a mouthwash containing cetylpyridinium and zinc chloride on reduction of morning oral malodor in healthy subjects measured by organoleptic measurement and a portable sulfide monitor. A total of 8 healthy non-smoking male volunteers were enrolled in this study of crossover design consisting of two experimental phases. The subjects were instructed to rinse the mouth with 10 mL of the experimental mouthwash containing cetylpyridinium and zinc chloride for 30 seconds at the first phase. At the second phase after a one-week washout period, each subject rinsed with distilled water as a control. All experiments were conducted at around 8:30 a.m. and oral malodor was measured using organoleptic measurement and a portable sulfide monitor just before rinsing with the experimental mouthwash or control (baseline), 1 hr, 2 hrs, and 3 hrs after rinsing. The mouthwash containing cetylpyridinium and zinc chloride reduced morning oral malodor up to 3 hrs after rinsing. Organoleptic score and concentrations of volatile sulfur compounds after use of the experimental mouthwash significantly decreased with time, and the decreases were significantly different between the mouthwash and control. In conclusion, the mouthwash containing cetylpyridinium and zinc chloride is significantly effective on reduction of morning oral malodor in healthy subjects by 3 hrs.

• Journal of Korean society of Dental Hygiene
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• v.10 no.6
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• pp.1107-1119
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• 2010

Objectivs : The purpose of this study is to provide basic data for the use of oral hygiene devices and to improve oral health care continuously by encouraging the use of oral hygiene devices. Methods : The survey was carried out by questionnaire research targeting 395 respondents in metropolitan area in June-August 2009. The collected data is analyzed by statistics program SPSS version 12.0. 1. General characteristics of subjects are analyzed by percentage and descriptive statistics. 2. Recognition about how to use oral hygiene devices, usage of oral hygiene devices, recognition of dental brush usage, Effect after using oral hygiene devices are analyzed by mean difference test(t, F verification). 3. Effect after using oral hygiene devices, relation of oral hygiene devices usage with subjective oral health status, oral hygiene devices usage and participation in education are analyzed by Correlation, Regression analysis. Results : 1. Investigation shows that most oral health devices are rarely used except toothbrush(4.57) in case of the use of oral hygiene devices. 2. In the case of awareness of oral hygiene devices usage, almost everyone knows how to use dental brushes(MEAN 4.16) the most. And the next ones are like these-tooth picks(MEAN 3.38), dental floss(MEAN 3.28), mouth rinse(MEAN 3.24). And they don't know how to use the other oral hygiene devices usage. 3. respondents who use dental floss(${\beta}$=.238, p<.001), interdental brush(${\beta}$=.242, p<.001) and water pik(${\beta}$ =.180, p<.05) recognize that the result and effect after using them are more positive than the others in different case. 4. Respondents who use toothbrush(${\beta}$=.119), dental floss(${\beta}$=.120) and interdental brush(${\beta}$=.136). frequently evaluate their subjective oral health status positively in case of frequency of using oral hygiene devices and subjective oral health status(p<.05). 5. Respondents who use toothbrush and interdental brush properly and frequently, who are older than the others show more concern about participating in education of "How to use oral hygiene devices" than the others(p<.05). Conclusions : In conclusion, to prevent oral disease, the opportunity of participating in education about correct knowledge and proper way should be expanded. And we should contribute to oral health improvement through developing, executing and informing systematic, popular oral health education with active one.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.301-310
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• 2018

The purpose of this study is to evaluate the compatibility of universal adhesives with two dual-cured resin cements. Eighty human molars were divided into eight groups. Tooth was embedded in self-curing acrylic resin and sectioned horizontally to exposure dentine surface. After polishing with 600-grit SiC paper, adhesives were applied. All-Bond Universal (Bisco), G-premio bond (GC), Scotch-bond universal (3M ESPE), Scotch-bond Multipurpose (3M ESPE) were used in this study. Calibra (Dentsply) as a conventional dual-curing resin cement and RelyX Ultimate (3M ESPE) as an amine free resin cement were used. The adhesives and the cements were applied according to the manufacturer's instructions. Final specimens were cylinder (diameter 2mm, height 3mm) shape. After storing in distilled water at $37^{\circ}C$ for 7 days the shear bond strength (SBS) test was performed. There was no significant difference in shear bond strength between the adhesives when RelyX Ultimate was used (p>0.05). However, when Calibra used with Scotch-bond Multipurpose and All-Bond Universal were used, statistically higher SBS was observed, as compared to the groups which Calibra cements with G-premio bond and Scotch-bond universal adhesive (p<0.05) were used. Within the limitations of this study, RelyX Ultimate resin cement was compatible with universal adhesives of various pH. All-Bond Universal adhesive was compatible with a resin cement containing the tertiary amine.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.1
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• pp.182-198
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• 2010

Background : The varieties of manifestations referred to oral, glottal, labial and dental diseases has been long complicated physicians in the efficient diagnosis and treatment of these diseases. Acupuncture has been widely used in Korea throughout the history and provides an efficient method in the treatment of them Objectives : Establish a distinctive and efficient acupuncture method for the treatment of oral, glottal, labial and dental diseases based in literature research Method : We reviewed four Korean medical literature, "Guide to Swollen Sore Treatment", "Treasured Mirror of Eastern Medicine", "Experiential Prescriptions of Acupuncture and Moxibustion", and "Essential Rhymes on Acupuncture and Moxibustion by Master Sa-am", and analyzed the therapeutic characteristics in the treatment of oral, glottal, labial and dental diseases Result : 1. According to "Guide to Swollen Sore Treatment", we could noted frequent application of blood letting methods in the affected area, then rinse ones mouth with salty water and further application of taro plaster. Also found acupuncture methods utilizing heated mole cricket or silkworm in the sublingual region. Regarding herbal method, Realgar was rubbed in the affected area. Mainly used acupuncture points in the treatment of oral, glottal, labial and dental diseases were GV20, GB20, LU5, and auricular anterior hairline 2. In "Treasured Mirror of Eastern Medicine", blood letting method in the sublingual region and burning needle searing method were the most frequently applied in the treatment of oral, glottal, labial and dental diseases. Moxibustion was also applied in the treatment of labial and dental diseases. Particularly, said to apply 3 moxa cones in ear zones of both sides, when no medicine is effective. This demonstrates how emphasized the importance of moxibustion in this kind of disease. Mainly used acupuncture points were GV16, CV24, LI4, EX-HN12, and EX-HN13 3. In "Experiential Prescriptions of Acupuncture and Moxibustion", no other methods beside wrist. Superstitious methods like applying moxibustion on the tooth picture drawn on the roofing tile need further confirmation. Mainly used acupuncture points were LI4, ST36, and HT7. 4. "Essential Rhymes on Acupuncture and Moxibustion by Master Sa-am", identified the cause of diseases according to visceral pattern identification. Stomach and Spleen in charge of vocal, lingual, and labial disease, Kidney for dental disease, and further scrutinizing identification according to Liver, Heart, Stomach, Lung, and Kidney manifestations. Used supplementation and draining needling methods of self meridians and other correlating meridians. Conclusions : After previous study on stroke and eye diseases, we could also find various efficient methods according to oral, glottal, labial and dental diseases, through literature research of korean medical classics. This study will concurrently result in establishing distinctive therapeutic method characteristic of Korea.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.400-420
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• 1998

We already know that it is very difficult to obtain an "isolated field" for direct bonding during the surgical exposure of unerupted teeth. The aim of this in-vitro study is to simulate the clinical situation of forced eruption and to evaluate the tensile strengths of preligatured button with several types of contamination which can happen during the surgical exposure of unerupted teeth. Four orthodontic direct bonding systems were used. ($Ortho-One^{TM}$, $Rely-a-Bond^{(R)}$, $Ortho-Two^{TM}$, Phase $II^{(R)}$) Each material was divided into four groups(n=20) : Group 1. (Control, no contamination), Group 2. (Rinse etching agent with saline instead of water), Group 3. (Blood contamination of etched surface for 30 seconds), Group 4. (Blood contamination of primed surface for 30 seconds) 320 bovine anterior permanent teeth were divided into the above mentioned 16 groups. Enamel surface was flattened and ground under water coolant. Pre-ligatured buttons were prepared to the same form. (Cut 0.25 ligature wire 10 cm in length. Twist the ligature wire 30 times clockwise. Mark the wire 15mm and 35mm points from button. Make a loop sticking two points together and twist the loop 6 times counterclockwise.) The bonded specimens were stored at $37^{\circ}C$ saline solution for 3 days. Then the tensile strength of each sample was measured with Instron universal testing machine, crosshead speed of 0.5mm/min. The following results were obtained: 1. As compared to control groups (Group 1) of each material, Rely-a-Bond had a significantly lower mean tensile strengths than other material. (p<0.01) 2. In Group 2. of Ortho-One and Rely-a-Bond, the mean tensile strengths decreased about 7.7% and 11.1%, respectively with statistical significances. (p<0.05) 3. In Group 2. of Ortho-Two and Phase II, the mean tensile strengths did not decrease. 4. In Group 3. of Ortho-One, Rely-a-Bond, Ortho-Two, and Phase II, the mean tensile strengths decreased about 60.8%, 56.1%, 60.2%, and 46.0%, respectively with statistical significances. (p<0.01) 5. In Group 4. of Ortho-One and Rely-a-Bond, the mean tensile strengths did not decrease. 6. In Group 4. of Ortho-Two and Phase II, the mean tensile strengths were decreased about 20.95% and 22.28%, respectively with statistical significances. (p<0.01) There were formations of a hump shaped mass from bonding resin under blood contamination which disturbed direct bonding procedure. According to Reynolds, the proper bond strength for clinical manipulation should be at least 45N or about 4.5Kg.F. According to these results, it can be concluded that Ortho-One could be used during surgical exposure of unerupted teeth. In any case, blood contamination of the etched surface should be avoided, but the blood contamination of primed surface of Ortho-One may not decrease bond strength. Just 'blowing-out' is enough to remove blood from primed surface of Ortho-One. You can verify the clean surface of the primer of Ortho-One after blowing out the blood contamination.

• Restorative Dentistry and Endodontics
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• v.33 no.1
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• pp.9-19
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• 2008

The purpose of this study was: (1) to compare nanoleakage patterns of a conventional 3-step etch and rinse adhesive system and two experimental hydrophobic adhesive systems and (2) to investigate the change of the nanoleakage patterns after load cycling. Two kinds of hydrophobic experimental adhesives, ethanol containing adhesive (EA) and methanol containing adhesive (MA), were prepared. Thirty extracted human molars were embedded in resin blocks and occlusal thirds of the crowns were removed. The polished dentin surfaces were etched with a 35 % phosphoric acid etching gel and rinsed with water. Scotchbond Multi-Purpose (MP), EA and MA were used for bonding procedure. Z-250 composite resin was built-up on the adhesive-treated surfaces. Five teeth of each dentin adhesive group were subjected to mechanical load cycling. The teeth were sectioned into 2 mm thick slabs and then stained with 50 % ammoniacal silver nitrate. Ten specimens for each group were examined under scanning electron microscope in backscattering electron mode. All photographs were analyzed using image analysis software. Three regions of each specimen were used for evaluation of the silver uptake within the hybrid layer. The area of silver deposition was calculated and expressed in gray value. Data were statistically analyzed by two-way ANOVA and post-hoc testing of multiple comparisons was done with the Scheffe's test. Silver particles were observed in all the groups. However, silver particles were more sparsely distributed in the EA group and the MA group than in the MP group (p < .0001). There were no changes in nanoleakage patterns after load cycling.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.37-44
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• 2013

Sodium hypochlorite and ethylene diamine tetra acetic acid are substances usually used during endodontic treatment. Several studies found that the bonding was negated with certain irrigants and some of the used irrigants have demineralizing and chealating effects, so it was advocated to omit the etching step in etch and rinse adhesive systems. The purpose of this in vitro study was to evaluate the influence of NaOCl & EDTA on the bonding strength of ethanol wet bonding. Thirty human molars were selected and mesiodistally sectioned into halves, thus providing sixty specimens. The specimens were randomly assigned to 4 groups(n=15) according to the irrigant regimen used : (1) irrigated with distilled water for 10min (control); (2) irrigated with 5.25% NaOCl(10min), flushed with 5.25% NaOCl(1min) (3) irrigated with 5.25% NaOCl, flushed with 17% EDTA (4) irrigated with 5.25% NaOCl, flushed with 17% EDTA. Each group was acid-etched with 37% phosphoric acid(except group 4) and had their dentin surfaces dehydrated with ethanol solutions : 50%, 70%, 80%, 95%, 3x100%, 30s for each application. After dehydration, a primer( 50% all bond 3 resin + 50% ethanol) was used, followed by the adhesive(ALL-BOND 3 RESIN) application. Resin composite build-ups were then prepared using an incremental technique. Specimens were sectioned into beams and submitted to a tensile load using a Micro Tensile Tester(Bisco Inc.). The data were statistically analyzed using one-way ANOVA and Tukey HSD at p<0.5 level. There was no significant difference on G1(control) and G2(irrigated with NaOCl only ). (p>0.05). G3(flushed with EDTA) showed significantly high tensile bonding strength compared to the G2 (p<0.05). G4( treated with EDTA but no acid-etching) was significantly lower value than G3. (p<0.05) Although there was no significant difference, 5.25% NaOCl seemed to have an adverse effect on the bonding strength of ethanol wet bonding. The flushing with EDTA after NaOCl irrigation prevents the decrease of bonding strength. The use of 17% EDTA as a final flush can enhance the bonding strength but EDTA flushing can't substitute for a acid-etching.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.335-341
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• 2004

This study was carried out to evaluate the microbiological quality of poultry carcasses at different slaughtering process in large (>50,000 chicken/day) and small (<30,000 chicken/day) scale slaughtering houses. Whole bird rinse technique was used to analyze the incidence of microorganisms on poultry carcasses in each process of before visceration, after evisceration, after final wash, after main chilling and in cold room. In summer time, small scale slaughterhouse showed lower incidence of aerobic microorganisms (10$\^$4/ CFU/mL) than those of large scale slaughterhouse (10$\^$5/ CFU/mL) at the process of after main chilling and in cold room. But small scale slaughterhouse showed higher incidence of E. coli (10$^2$-10$^4$ CFU/mL) than those of large scale slaughterhouse (10$\^$-2/ CFU/mL) at each slaughtering process observed. During autumn and winter time, small scale slaughterhouse showed similar incidence of aerobic microorganisms as large scale slaughterhouse (10$\^$5/ CFU/mL after evisceration, 10$^4$ CFU/mL after main chilling and cold storage). Samples from carcasses during autumn and winter time in cold room showed no difference in E. coli counts (10$^2$ in autumn time and 10$^3$ CFU/mL in winter time) between large and small scale slaughterhouse. In spring time, small scale slaughterhouse showed lower incidence of aerobic microorganisms than those of large scale slaughterhouse at each slaughtering process observed except after main chilling. Small scale slaughterhouse showed higher incidence of aerobic microorganisms in final cooling water than large scale slaughterhouse during spring time.

• Journal of dental hygiene science
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• v.1 no.1
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• pp.21-27
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• 2001

The purpose of this study was to explore some of the right directions for school dental-health education, by examining nursing students' knowledge on and attitude to the two major oral diseases in our country, dental caries and periodontal disease, as they will take charge of dental-health education and care for children in school dental-health center as sole expert health personnels after graduation. As a result of making an analysis of their knowledge and attitude, the following findings were acquired: (1) The students investigated perceived their oral cavity to tend to be healthy(36.8%) or in moderate situation(36.3%), although they had a subjective symptom for hot or cold food. (2) They thought dental caries is attributed to poor dental hygiene care(90.4%). Among them, 94.1% found toothbrushing effective for the prevention of dental caries, but just 40.2% agreed that toothbrush should be straight. (3) Those who considered fluoride effective for dental caries prevention thought the best way to use fluoride is taking fluoride-containing tap water(2.00). The second best way was fluoride mouth rinse(2.40), followed by the topical application of fluoride(2.70), use of fluoride dentifrice, and intake of fluoride(4.30) in the order named. (4) The regular examination and toothbrushing were mentioned as a way to prevent dental caries, but just toothbrushing was put in action for dental health. So their knowledge and actual attitude weren't the same. (5) They brushed their teeth for oral health(94.3%). Toothbrushing was done after breakfast(71.9%) or before bedtime(65.8%). Just 40.3% performed toothbrushing after lunch. That was implemented twice(35.7%) or three times(37.6%) a day. (6) Out of those who pointed out toothbrushing as a way to prevent periodontal diseases(84.7%), the effect of toothbrushing on the prevention of periodontitis wasn't supported by 7.1% of those who completed the course of study for the teaching profession and by 17.0% of the others who didn't. The two groups weren't of the same opinion. The above-mentioned findings suggest that the dental knowledge of the nursing students wasn't good enough to be properly responsible for school children's dental health care. In particular, there was a gap between knowledge and attitude. To improve children's poor dental health and help their oral cavity stay healthy, there is a need to activate school dental-health center, which is now in model operation, and to make the most of dental hygienists, who are educated to be a dental-health specialist, for more successful dental-health care for school children.