• Korean Journal of Food Science and Technology
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• v.43 no.2
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• pp.182-188
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• 2011

Excess sugar intake by food consumption may contribute to the development of diabetes, dental caries, attention deficit hyperactivity disorder (ADHD), and cardiovascular disease. The objective of this study was to investigate the sugar intake from meals at nursery schools in Gyeonggi-Do, and to construct a database for reduction policies sugar intake. A total of 601 samples were analyzed for sugar intake in summer and winter, respectively. The average sugar intake from food service was 2.22 g/meal, which was 5% of the Recommended Daily Intake (RDI). Furthermore, the analysis results of sugar content were in the decreasing order of fruits (5.05 g/100 g), fried food (2.92 g/100 g), and braised food (2.31 g/100 g). The habit of excessive sugar intake in childhood can be threaten health in adulthood. Thus, it is necessary for nursery school children to consume schoolmeals that contain less sugar.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.165-176
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• 2014

Purpose: The effects of desensitizing agent are often for a short duration. One of the reasons is believed to be wear of desensitizing agent by tooth brushing. To reduce the wear and make the duration longer, dental bonding resin was applied and the changes of dentin permeability after toothbrushing were measured. Materials and methods: Extracted teeth free from caries were chosen. Coronal dentin discs with thickness of 1 mm were prepared. Using the split chamber device developed by Pashely, hydraulic conductance and scanning electron microscope images (SEM) were compared and contrasted before and immediately after the application of desensitizing agent and bonding resin and then after equivalent tooth brushing of 1 week, 2 weeks, and 6 weeks. Four commercially available desensitizing agents were used in this study; they were All-Bond 2, Seal & Protect, Gluma, and MS Coat. And Dentin/Enamel Bonding resin (Bisco Inc.) was used. The results of this study are as follows. Results: On all specimens, the hydraulic conductance decreased after the application of tooth desensitizing agent and bonding resin. Compared with the specimens treated only with desensitizer, the specimens treated with All-Bond 2, Gluma, MS Coat and plus D/E bonding resin had a little increase in hydraulic conductance after 1, 2 and 6-week tooth brushing. In case of Seal & Protect, the specimens showed the same result only after 6-week tooth brushing. On examination of SEM, the dentinal tubule diameter had decreased after treatment of desensitizing agents and bonding resin. And the specimens treated with All-Bond2, Seal&Protect, Gluma, MS Coat and plus D/E bonding resin had an significant decrease in diameter of dentinal tubule after 6-week tooth brushing. Conclusion: According to the results of this study, it is effective to use bonding resin after application of desensitizer in reducing the wear by tooth brushing and making the duration longer. In this study, just 6-week tooth brushing was performed, and it is not enough to regard it as a long-term data. So further study is needed and more perfect method for treating dentin hypersensitivity should be developed.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.54-66
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• 2001

The aim of this study was to investigate the fluoride release and some mechanical properties including 3-point bending strength, amount of abrasion, surface hardness, water sorption/solubility and cytotoxicity of the newly developed composite resins containing 8, 16, 24 wt% $SrF_2$ glass filler (VF8, VF16, VF24) and four commercially available composite resins, Heliomolar(HE), Verdonfil(VE), Z100(ZH) and Aelitefil(AE). To investigate cytotoxic effect, agar overlay assay was done. Amount of fluoride released into distilled water was measured over a 62-days period from VF8, VF16, VF24 and HE. Results were as follows: 1. Experimental composite resins showed similar mechanical properties to commercial composite resins, but 3-point bending strength and surface hardness of experimental composite resins were inferior to ZH. 2. Over a 62-day Period, the amount of fluoride released was ordered: VF24>VF16>VF8>HE. In experimental composite resins, the amount of fluoride released was 9-23 times greater than HE and seemed to be proportional to the content of $SrF_2$ glass filler. 3. Experimental composite resins and all control composite resins showed mild cytotoxicity. This study showed significantly greater fluoride release from newly developed composite resins than control(HE) and addition of $SrF_2$ glass filler did not decrease mechanical properties or increase cytotoxicity of composite resin. The results from this study imply that newly developed composite resin have adequate mechanical properites, mild cytotoxicity and some potential for secondary caries prevention.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.404-411
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• 2009

Drinking water has lots of minerals, especially calcium, sodium, kalium, magnesium, and fluoride must be labelled on the bottle about their contents. Minerals like calcium, magnesium, and fluoride have influence to the tooth development. Appropriately taking some minerals, dental caries can be prevented somewhat degree. There is no guide line about innoxious minerals like calcium and magnesium, however, noxious mineral like fluoride, should be contained less than 2 mgF/L according to the current drinking water standard. Hereupon, it is necessary to recognize the concentration of fluoride in drinking water, so I studied 15 samples of domestic drinking water on sale about the concentration of calcium and magnesium, fluoride. The results obtained were as follows ; 1. 14 drinking waters in 15 samples showed various Ca concentration. The average Ca concentration is 34.68${\pm}$31.84 mg/L, the highest is 128.91${\pm}$1.85 mg/L and the lowest is 2.0${\pm}$0.02 mg/L. 2. 13 drinking waters in 15 samples indicate the Mg concentration. The average concentration is 9.22${\pm}$11.06 mg/L, the highest is 30.43${\pm}$0.75 mg/L and the lowest is 0.0 mg/L. 3. 11 drinking waters in 15 samples indicate the F concentration. The average concentration is 0.25${\pm}$0.33 mg/L, the highest is 1.13${\pm}$0.04 mg/L and the lowest is 0.01${\pm}$0.03 mg/L. All samples are satisfied the current drinking water standard, 2 mg F/L.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.446-453
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• 2020

The purpose of this study was to evaluate the effect of Indocyanine Green (ICG) and near-infrared (NIR) diode laser on Streptococcus mutans biofilms depending on ICG concentrations. S. mutans biofilms were formed on a Hydroxyapatite disk, and 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 mg/mL ICG solutions dissolved in sterile distilled water and a NIR diode laser having a power of 300 mW and a wavelength of 808 nm were applied to the biofilms. The temperature changes of the biofilm surface according to the concentrations of the ICG solution were measured using a 1-channel thermocouple thermometer. Compared to the control group, in the groups with only the 3.0, 4.0, 5.0 mg/mL ICG solution application, and in the groups with the 1.0, 2.0, 3.0, 4.0, 5.0 mg/mL ICG solution application and light irradiation, a statistically significant decrease in the bacterial counts were observed. The temperature increase according to the concentration of the ICG solutions was 9.53℃, 10.43℃, 11.40℃, 12.10℃, 12.67℃, and 13.63℃ in ICG solutions of 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 mg/mL respectively. This study presents the potential for clinical application of ICG and NIR diode lasers as a new method for preventing dental caries.

• Journal of the Korean Society of School Health
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• v.12 no.2
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• pp.295-303
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• 1999

The purpose of this study was to evaluate the effect of systemic oral health education on the improvement of knowledge levels and patient hygiene performance(PHP) for elementary school students. The randomly selected 1st and 5th grade students in a public elementary school of Taegu city were divided by education group(118 students) and non-education group(122 students). The oral health education lesson was systematically held on the education group once a month for 4 months. The questionnaire queried all the subjects about their knowledge and attitudes before and after oral health education, and PHP was also tested at the same time. Corresponding p-values were significantly considered at values less than 0.05. The obtained results were as follows: Due to the oral health education lesson, the education group of both 1st and 5th grade students came to have a higher knowledge level than the non-education group. There was high improvement of items such as toothbrushing time, toothbrushing method, cause of dental caries, treatment after tooth damage, and tongue-brushing. Therefore, these items should be educated to all the elementary school students. By increaseing the knowledge level of oral health after education, the PHP index in the education group was significantly decreased in comparison to the non-education group and hence the capability of oral health management improved. From the above results, a systematically and periodically oral health education system for elementary school students can improve the knowledge level and capability of oral health management. Further study will be required to develop an easy and acceptable systemic oral health education program for elementary schools.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.520-527
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• 2008

Purpose: This study was conducted to evaluate the shear bond strength of composite resin to dentin when etched with laser instead of phosphoric acid. Material and methods: Recently extracted forty molars, completely free of dental caries, were embedded into acrylic resin. After exposing dentin with diamond saw, teeth surface were polished with a series of SiC paper. The teeth were divided into four groups composed of 10 specimens each; 1) no surface treated group as a control 2) acid-etched with 35%-phosphoric acid 3) Er:YAG laser treated 4) Er,Cr:YSGG laser treated. A dentin bonding agent (Adapter Single Bond2, 3M/ESPE) was applied to the specimens and then transparent plastic tubes (3 mm of height and diameter) were placed on each dentin. The composite resin was inserted into the tubes and cured. All the specimens were stored in distilled water at $37^{\circ}C$ for 24 hours and the shear bond strength was measured using a universal testing machine (Z020, Zwick, Germany). The data of tensile bond strength were statistically analyzed by one-way ANOVA and Duncan's test at ${\alpha}$= 0.05. Results: The bond strengths of Er:YAG laser-treated group was $3.98{\pm}0.88$ MPa and Er,Cr:YSGG laser-treated group showed $3.70{\pm}1.55$ MPa. There were no significant differences between two laser groups. The control group showed the lowest bond strength, $1.52{\pm}0.42$ MPa and the highest shear bond strength was presented in acid-etched group, $7.10{\pm}1.86$ MPa (P < .05). Conclusion: Laser-etched group exhibited significantly higer bond strength than that of control group, while still weaker than that of the phosphoric acid-etched group.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.1
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• pp.20-26
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• 2013

Purpose: The purpose of this study was to evaluate the bond strengths between the latest CAD/CAM ceramic inlay and various resin cements which are used primarily for esthetic restoration. Materials and methods: Cylindrical ceramic blocks(Height: 5 mm, diameter: 3 mm) were fabricated by using Cerec3 and bonded on the dentin of the ninety extracted caries-free molars using three different kinds of resin cement(Unicem$^{(R)}$, Biscem$^{(R)}$, and Variolink II$^{(R)}$) according to the manufacturer's instructions. Ninety specimens were divided into 3 groups according to three different kinds of resin cement. Half of each group were conducted thermocycling under the conditions of the $5-55^{\circ}C$, 5,000 cycle but the other half of them weren't. All specimens were kept in normal saline $37^{\circ}C$, for 24 hours before measuring the bond strength. The shear bond strength was measured by Universal testing machine with a cross head speed of 0.5 mm/min. The results were analyzed statistically by t-test and one-way ANOVA. Results: Unicem$^{(R)}$ group showed the highest shear bond strength despite a slight decline by thermocycling. The shear bond strength of Unicem$^{(R)}$ group and ValiolinkII$^{(R)}$ group were significantly influenced by thermocycling, whereas Biscem$^{(R)}$ group was not influenced (P<.05). There were no significant differences in the bond strength between the three groups without thermocycling, but there was significant differences between Unicem$^{(R)}$ group and Valiolink II$^{(R)}$ group with thermocycling(P<.05). Conclusion: It has been shown to be clinically effective when the self-adhesive resin cements Unicem$^{(R)}$ and Biscem$^{(R)}$ were used instead of the etch-and-rinse resin cement Valiolink II$^{(R)}$ during the bonding of CAD/CAM ceramic inlay restorations with teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.411-421
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• 2006

In children, during developing occlusion stage, many studies confirm a high prevalence of gingival inflammation. Prevention, early diagnosis and treatment of gingival and periodontal disease is important because by establishing excellent oral hygiene habits in children, the risk of periodontal disease can be on the decrease in adulthood. This study evaluated the gingival conditions of 50 children$(8.5{\pm}3.1years)$ and 20 $adults(26.1{\pm}3.3 years)$ receiving clinical examination and GCF test at the pediatric dentistry of Chonbuk national university hospital in Jeonju, Korea. I estimated children's and adult's gingival states by measuring gingival crevicular fluid(GCF) using Periopaper and $Periotron^{(R)}$ 8000, gingival index, plaque index, DMFT scale. The results were as follows : 1. There are no statistical differences of GCF volume among the groups of the primary dentition, tooth erupting stage, complete eruption stage(p>0.1). But mean value of GCF is highest at the tooth erupting stage. 2. Comparing with adults, children have higher mean value of GCF volume with statistical differences (p<0.001). 3. There is statistically positive relationship between volume of GCF and gingival index (GI), plaque index(PLI) in both adults and children(GI; r=0.394, PLI ; r= 0.642). 4. There is no relationship between GCF volume and dental caries, composite resin treatments (p>0.05). But There is statistically positive relationship between GCF and orthodontic treatments(p<0.001) 5. Primary dentition has higher mean value of DMFT than permanent dentition(p<0.001). But there is no statistical relationship between GCF and DMFT (p>0.1).

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.375-381
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• 2007

Occlusal stabilization appliance is one of the most common treatment option for management of temporomandibular disorders. It acts in oral cavity for several hours per day, and usually it will take at least 6 months to 2 years of total wearing periods to take a treatment goal. In the oral cavity, occlusal stabilization appliance, unintentional manner, is able to acts as a reservoir of bacteria and protect bacteria from saliva and oxygen. This condition is so favorable to many bacteria such as S. mutans and other anaerobes, usually have been reported as causative factors of dental caries, periodontal disease and oral malodor. In this study, we investigated anaerobic bacteria and S. mutans count before and after occlusal stabilization appliance use to evaluate the possible role of occlusal stabilization appliance as protector of these bacteria. Four men(average 27.5 years) wore maxillary occlusal stabilization appliance at each night(average 9 hours) for 5 days. we swabbed saliva-plaque mixed sample at 3 different site(maxillary left 2nd molar, maxillary left central incisor, mandibular left 2nd molar) before and after occlusal stabilization appliance use. Each samples were plated in (1) anaerobic blood agar medium, (2) selective S. mutans medium(MS-MUTV) and incubated in anaerobic chamber($CO^2$ 10%, $37^{\circ}C$) for 72 hours. Each bacterial colony forming unit(CFU) were counted with naked eyes. From obtained data, we can conclude as follows: 1. There was some changes about anaerobic bacteria and S. mutans count in oral cavity after occlusal stabilization appliance use. 2. The number of anaerobic bacteria was significantly increased at maxillary 2nd molar(P=0.003), maxillary central incisor(P=0.020) after occlusal stabilization appliance use compared with before. 3. Occlusal stabilization appliance use itself had indirect effect to increase the number of anaerobic bacteria at other uncovered opponent tooth site. 4. The number of S. mutans was significantly increased at maxillary 2nd molar(P=0.043), maxillary central incisor (P=0.049) after occlusal stabilization appliance use compared with before. 5. Occlusal stabilization appliance use itself had not any effect on the number of S. mutans at other uncovered opponent tooth site.