• Journal of dental hygiene science
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• v.10 no.2
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• pp.95-100
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• 2010

The purposes of this study were to examine the effect of different fluoridated bleaching solution on the changes in physical and chemical characteristics of tooth. Forty-eight bovine incisors were divided into four groups to receive bleaching treatments, over a 14days period, as follows: no treatment; 10% carbamide peroxide (CP) bleaching; 10% CP containing 0.05% fluoride; and 10% CP containing 0.1% fluoride. All the specimens were highly polished and discolored with commercial COCK.Color and enamel changes were determined with colorimeter, microhardness tester, scanning electron microscope, atomic force microscopy. All the collected data were analyzed with one-way ANOVA. After the bleaching, bleached groups showed the color change(E*). Microhardness of 10% CP group decreased after tooth bleaching. But microhardness of containing fluoride bleached groups increased after tooth bleaching. Enamel surface of 10% CP bleached group showed any apparent morphology and roughness changes compared to the enamel which was stored in distilled water only. These results demonstrated that Fluoridated 10% Carbamide Peroxide have appreciable bleaching effect on bovine teeth and were not adversely affects enamel. Supporting influence of fluoride-containing bleaching solution on remineralization could be observed and further research must be carried out in various active environments to confirm these results clinically.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.223-229
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• 2014

The aim of this study was to examine the effect of polycan-calcium gluconate complex on the levels of immune and inflammatory mediators in gingival crevicular fluid and serum from patients with periodontitis. A total of 39 patients with periodontitis took placebo (placebo group) or polycan-calcium gluconate complex (treatment group) twice a day for 4 weeks. At baseline and 4 weeks, gingival crevicular fluid (GCF) and blood was collected from each subjects. The secretion level of interleukin $(IL)-1{\beta}$ in GCF was measured by enzyme-linked immunosorbent assay (ELISA). Western blot analysis was conducted to determine the expression of matrix metalloproteinase (MMP)-8 and tumor necrosis factor $(TNF)-{\alpha}$ in GCF. Serum samples were analysed for MMP-8 by ELISA and C-reactive protein (CRP) by turbidimetric immuno assay. MMP-8 and $TNF-{\alpha}$ were significantly decreased in the treatment group at 4 weeks. The level of $IL-1{\beta}$ in the treatment group was significantly lower than those of the placebo group. No differences were observed in CRP levels. Taken together, these data indicate that taking of polycan-calcium gluconate complex led to reduction of inflammatory biomarkers in serum and GCF of periodontitis patients.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.407-412
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• 2015

This study investigated flexural properties of indirect Gum-shade composite resins for esthetic improvement. The material utilized in this study was Crea.lign, Twiny flow and Twiny paste (TP). Ten specimens were fabricated with a dimension of $25{\times}2{\times}2mm$ according to the ISO 4049. After fabrications, specimens were stored in the distilled water for 24 hours at the temperature of $37^{\circ}C$. Three-point bending test was performed in universal testing machine (Instron 3344; Instron, USA) at a crosshead speed of 1 mm/min until the failure occurred. TP exhibited a higher flexural strength (FS) and flexural modulus (FM) compared to the flowable materials. There were significant differences among the three materials in FS and FM. However, there was no significant difference in work of fracture (WOF) in all tested materials (p>0.05). In Weibull analysis, TP showed the greatest Weibull modulus which means a higher reliability of the materials. Also, Gum-shade composite resins revealed a strong correlation in all flexural properties. There was a positive correlation in FS-FM ($r^2=0.99$) and a negative correlation between FS-WOF and FM-WOF ($r^2>0.97$). Therefore, this confirmed that flexural property was important for mechanical behavior evaluation and useful information. To addition, this improved among mechanical properties correlation of materials as important factor.

• Journal of dental hygiene science
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• v.11 no.5
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• pp.411-416
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• 2011

Streptococcus mutans (S. mutans) is the major causative bacteria in dental caries. Xylitol is effective anticarious natural sugar substitute by inhibiting the virulence of S. mutans. However, long-term xylitol consumption leads to the emergence of the xylitol-resistant (XR) strains which means xylitol is no more inhibited their growth. We therefore confirmed the general characteristics and the virulence factors of the xylitol-sensitive (XS) and XR S. mutans for different concentrations of xylitol. S. mutans KCTC 3065 was maintained in TYE medium containing 0.4% glucose with 1% xylitol during 30 days at $37^{\circ}C$, 10% $CO_2$ to form XR strain. The strains were transferred to new medium every 24 hr and the same procedures without xylitol were repeated for the formation of XS S. mutans. Both XS and XR were cultured in different concentrations of xylitol (0%, 0.1% and 1%) then, cell growth, acid production and mRNA expression of gtf genes were analyzed. Xylitol reduced the cell growth of XS S. mutans in dose-dependent manner, but not reduced that of XR. Xylitol inhibited acid production of XS in dose-dependent manner, but not inhibited that of XR. Xylitol reduced the gtfB and gtfD mRNA expression of XS S. mutans which genes synthesized soluble and insoluble extracellular polysaccharides, but not reduced that of XR. These results indicate that the virulence of XR S. mutans is different characters of XS strains, which suggests XR strains may have different cariogenicity of XS strains. Further study is needed to explain the mechanism related to extracellular polysaccharide in the XR strains.

• Journal of dental hygiene science
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• v.13 no.1
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• pp.105-114
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• 2013

The purpose of this study was to offer information to medical institution of specializing in orthodontic patients by surveying the influence of orthodontic patients' perception of treatment according to orthodontic treatment upon satisfaction and recommendation with orthodontic treatment, targeting patients with completion of orthodontics who have experience of having received orthodontic treatment. As a result of SAS ver. 9.1 analysis on what was surveyed from February 2010 to August, the following conclusions were obtained. In comparing perception of treatment on orthodontic treatment according to general characteristics, women compared to men were indicated to be higher (p<0.05) in inconvenience recognition (p<0.05) on orthodontic device and in inconvenience during orthodontic treatment (p<0.05). In perception of treatment on orthodontic treatment, the inconvenience of orthodontic device accounted for 79.3%, thereby having been recognized by the majority of subjects. Even the inconvenience during orthodontic treatment was being recognized by 69.8%. The orthodontic treatment expenses appeared enough to be expected by 61.6%. The frequency of visiting hospital during orthodontic treatment was indicated as saying of having been proper by 72.8%. The period of orthodontic treatment was indicated to be proper as well by 61.2%. Even understanding about treatment contents during orthodontic treatment was indicated to be understood by 62.6%. In the results of correlation among subjects' cooperation with dental treatment, satisfaction with treatment service, recommendation of this clinic, and satisfaction with the convenient facilities, the significantly positive correlation was shown (p<0.05) in all among items in each.

• Journal of dental hygiene science
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• v.8 no.4
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• pp.255-260
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• 2008

The purposes of this study were to examine the effect of 35% hydrogen peroxide (HP) bleaching agent on the changes in physical and chemical characteristics of tooth. The bleached teeth showed an apparent color changes. The whiteness increased linearly within the tested period as the period of bleaching increased. The microhardness between bleached groups after bleaching showed any statistically significant difference according to the paried t-test. The bleached enamel surface showed any apparent morphological changes compared to the enamel which was stored in distilled water only. The difference of the total mineral contents for the distilled water and hydrogen peroxide did not show statistical significance. These results demonstrated that bleaching using 35% hydrogen peroxide were adversely affects application time of experimental group and may confirm the safety of using these agents for a short time in dentist-monitored bleaching.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.226-231
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• 2015

The purpose of this study was to evaluate the accuracy of model according to three types of dental scanner. A maxillary acrylic model was prepared and duplicated 10 times by silicone impression materials. Corresponding working casts were formed from scannable stone and got a 3-dimensional digital models using three different scanners. The distance of each measurement region was measured using vernier calipers and the respective program. One-way ANOVA and the Tukey honestly significant difference post hoc test (${\alpha}=0.05$) was performed using IBM SPSS Statistics 21.0. Overall, the stone cast is smaller than the digital models in measurement distance. And measuring point value of laser scanner showed the most similar values and measurement points value of digital vernier calipers. Digital model of white light scanner showed similar values in the measurement points value of the blue light scanner. In conclusion, the laser scanner showed the best accuracy among the three types of dental scanner. However, the difference between the digital models and the stone cast can be accommodated in making prostheses. Thereby, three types of dental scanner are available in a clinically acceptable range.

• Journal of dental hygiene science
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• v.11 no.6
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• pp.497-503
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• 2011

The purpose of this study was to examine the effect of a program geared toward improving elderly people's oral function. After a program was provided to the selected elderly people free of charge for three months, they were asked to rate their own oral function to see whether they underwent any changes after their participation in the program, and their oral function was tested to obtain objective data. The collected data were analyzed by the statistical package SPSS WIN 18.0. The findings of the study were as follows: As for changes in their self-rated indicators of oral function, they faced less troubles in most of the oral function items after they participated in the program, and there were statistically significant differences in some of the items. As a result of making an objective evaluation of their oral function, they underwent a little change in salivary flow rate from 1.19 to 1.30, though the change was not statistically significant. In terms of opening, they showed a statistically significant rise of scores from 4.22 to 4.53, and they also showed a statistically significant rise of scores in pronunciation from 30.52 to 38.88. Regarding satisfaction with the program, they gave 4.48 to the program, which implied that they were greatly satisfied with the program. The abovementioned findings suggest that oral health experts and program providers should try to encourage elderly people to keep on taking oral health programs with interest. Currently, oral exercise programs are conducted in some public health centers and in the field of clinical dentistry, and it's required to offer more oral exercise programs as community exercise programs for the elderly.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.295-300
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• 2010

The aim of this study were to elucidate effects of fluoridated bleaching agents and post-treatment fluoride application on the color and microhardness of enamel surface. Twenty freshly extracted human adult molar were each sectioned into halves, the specimens divided and treated according to four experimental groups: 1, untreated controls: 2, treatment with 10% carbamide peroxide (CP) bleaching agent; 3, treatment with 10% CP containing 0.11% fluoride; 4, treatment with 10% CP followed by a 0.9% sodium fluoride gel application. Group 2-4 were compared with the baseline data. treated 8 h per day for 14 days then immersed in distilled water for 2 weeks. Changes in enamel color and microhardness were evaluated on Days 7 and 14. All the bleached enamel specimens revealed increased whiteness and overall color value. Groups 2 and 4 showed significantly decreased enamel microhardness compared to their baseline. The specimens treated with fluoridated bleaching agents showed relatively less reduction in enamel microhardness than those treated with nonfluoridated agents during the bleaching treatment. The addition of fluoride did not impede the tooth whitening. The fluoridated bleaching agents reduced the microhardness loss of enamel.

• Journal of dental hygiene science
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• v.12 no.5
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• pp.511-515
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• 2012

The aim of this study was to investigate the effects of dental plaque control depending on the detergent foods. Study design was a nonequivalent control group design. Study subjects were 14 males (38.8%) and 22 females (61.1%), the age of 20.6 years old. It was conducted from March 7 to June 13, 2012. The Patient Hygiene Performance index (PHP index) was measured as a dependent variable. Detergent foods were cucumber, pear, carrot, and peach. The PHP index of detergents foods were compared using ANOVA. Paired t-test was performed. SPSS ver. 18.0 was used for the data analysis. All detergent foods which cucumber ($2.85{\pm}1.01$), pear ($2.82{\pm}0.93$), peach ($2.48{\pm}1.12$), and carrot ($2.75{\pm}0.68$) was a significant decrease in plaque index (p<0.05). However, there was no significant difference among detergent foods. Detergent foods are effective in dental plaque control. However, no difference was shown depending on the detergent foods.