• Journal of dental hygiene science
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• v.14 no.4
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• pp.554-562
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• 2014

This study was conducted to identify the factors influencing toothbrushing behaviors of elementary school students by adding the variable of 'self-efficacy' to the behavioral model based on the theory of planned behavior. To collect the data for an analysis, the self-administered questionnaire was distributed to 443 students in 4th to 6th grades of elementary school placed in Inchon Metropolitan City. The statistical package of PASW 18.0 was employed for the analysis. Results of the analysis revealed that the toothbrushing intention was explained by the subjective norm (${\beta}=0.343$), the self-efficacy (${\beta}=0.171$), the perceived behavioral control (${\beta}=0.163$), and the attitude toward the tooth-brushing behavior (${\beta}=0.135$). The toothbrushing behavior was explained by the toothbrushing intention (${\beta}=0.355$) and the self-efficacy (${\beta}=0.113$). The synthesis of such results suggested that both parents and teachers in school who would be influential to students should guide elementary school students to be habituated to the right toothbrushing. Also it was estimated that the students should understand the importance of toothbrushing through proper oral health education, and they should also become confident in spontaneous toothbrushing by providing them with an environment that could help them practicing the toothbrushing easily.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.144-151
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• 2005

Erosion is believed to be the predominant cause of teeth wear in children and young adults, although there will at ways be a contribution from attrition and abrasion. The pH of cola is known to be low and have, therefore, been implicated in the increasing incidence of erosion. The aim of present study was to evaluate the effect of cola on the progression of erosive demineralization in human enamel using demineralization model in vitro. Six groups of human enamel slap were immersed(5 min each bath) in fresh cola, with immersions taking place with or without agitation, and under 3 regimes of frequency intake(low intake, 1 immersion/day; medium, 5/day; high, 10/day). Quantitative assessments of surface erosion were done over an 8-day interval using surface microhardness testing. 1. The average pH of cola was 2.5, which was acidic enough to cause tooth erosion. 2. All the enamel specimen exposed to cola showed erosion like lesions and surface hardness decreased in proportion to the length of immersion (p<0.05). 3. The surface hardness of enamel decreased in proportion to the frequency of immersion (p<0.05). 4. Increased degassing from the drink by gitation accelerated the enamel softening compared with those without agitation.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.30-38
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• 2008

Dental pulp cells are assumed to possess the capacity to elaborate both bone and dentin matrix under the pathological conditions following tooth injury. The purpose of this study is to examine the effects of mineral trioxide aggregate (MTA) on various gene expression regarding dentinogenesis and cell viability assay in cultured primary human dental pulp cells. The author also examined the effects of this material on cellular alkaline phosphatase activity as a potential indicator of dentinogenesis. For gene expression on MTA, reverse transcriptase polymerase chain reaction was performed using primer sets of glyceraldehyde-3-phosphate dehydrogenase, type I collagen, alkaline phosphatase(ALP), osteonectin, and dentin sialoprotein after 2 and 4 days. Cell viability assay showed that the proportion of MTA-treated pulp cells which had been exposed for 5 days to MTA was higher than that of the control cells. Among the genes investigated in this study, ALP and osteonectin(SPARC) were increased in MTA treated group than in control. These findings suggest that this dental pulp culture system may be useful in the future as a model for studying the mechanisms underlying dentin regeneration after the treatment with MTA. Exposure to MTA material would not induce cytotoxic response in the dental pulp cells. In addition, MTA could influence the behavior of human pulp cells by increasing the ALP activity and SPARC synthesis.

• Journal of Korean society of Dental Hygiene
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• v.12 no.3
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• pp.521-531
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• 2012

Objectives : The aim of this study was to evaluate the relation between the state of dental health(number of natural teeth) and nutritional status of Korean elderly using Korean Dietary Reference Intakes, which was an objective standard for nutritional intake based on database of Korea National Health and Nutrition Examination Survey, large scale of sample obtained by the government. Methods : Complex sampling procedure was used to analyze the fourth data(2007-2009) of Korea National Health and Nutrition Examination Survey. When preparing planning file, the estimator of variance as a stratification variance (variance name : kstrata), population of survey unit as a cluster variance(variance name : PSU), and previous exam and nutritional related weighted as a weighted were analyzed by considering reproduced survey and nutritional related total weighted. Complex samples chi-square test was used to estimate the relation between number of natural teeth and inadequate intake and relation factors included in the model were analyzed by complex samples logistic regression analysis. Results : The group of edentulous had a higher risk to intake less nutrient, except calcium, riboflavin and vitamin C than recommended level comparing to reference group which had natural teeth more than 20(phosphate : OR=1.763; 95% CI=1.273-2.443, thiamine : OR=1.748; 95% CI=1.276-2.395, protein : OR=1.610; 95% CI=1.213-2.138). Conclusions : The number of teeth in Korean elderly over 65 years old had a relation with nutritional status in this investigation. Especially, intake level of nutrients was different between the edentulous group and the reference group. Therefore, dental health care is needed from young and middle age to keep health dental condition for through whole life as well as old age. Although the dental condition of the aged is not good, it is evitable to educate them about the relation between dental health and nutritional ingestion to take balanced nutrition, we think.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.55-69
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• 1987

The purpose of this study was to evaluate the stress distributions of the fixed partial denture with five unit intermediate abutment. This fixed partial denture was attached to a three dimensional photoelastic epoxy resin model. Three dimensional photoelastic models were used, with the stress areas recorded photographically. A vertical load was applied to the second molar, which is the most posterior abutment of the fixed partial denture. Similarly, a vertical load was applied to the first molar because this tooth receives the heaviest masticatory load. These loads were added to two types of fixed partial denture. the rigid connector, and the nonrigid connector which was connected on the distal side of the intermediate abutment by a key and keyway device. After the stress patterns in surrounding tissues were observed, the following conclusions were as follows: 1. When the vertical load was applied to the first and second molars on the occlusal surfaces, the surrounding tissues of the roots of the canine, the second premolar, and the second molar were all compressive stresses. 2. When the vertical load was applied on the occlusal surface of the second molar, the tissue surrounding the roots of the canine, the second premolar, and the second molar all showed more stresses with the nonrigid connector than with the rigid connector. 3. When the vertical load was applied to the occlusal surface of the first molar, the stress concentration on the canine and the second molar was similar, whether the rigid or nonrigic connectors were used. However, on the second premolar, the stress concentration shown by the nonrigid connector was noticeably more than that shown by the rigid connector. 4. Whether the rigid or nonrigid connectors were used, when the load was placed on the first molar, the stress concentration on the canine and the second premolar was greater than that observed for the second molar. When the load was placed on the second molar, the load affected the second molar more than the canine and the second premolar.

• The Journal of Advanced Prosthodontics
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• v.7 no.4
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• pp.271-277
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• 2015

PURPOSE. This study was to evaluate the marginal fit of two CAD-CAM anatomic contour zirconia crown systems compared to lithium disilicate glass-ceramic crowns. MATERIALS AND METHODS. Shoulder and deep chamfer margin were formed on each acrylic resin tooth model of a maxillary first premolar. Two CAD-CAM systems (Prettau$^{(R)}$Zirconia and ZENOSTAR$^{(R)}$ZR translucent) and lithium disilicate glass ceramic (IPS e.max$^{(R)}$press) crowns were made (n=16). Each crown was bonded to stone dies with resin cement (Rely X Unicem). Marginal gap and absolute marginal discrepancy of crowns were measured using a light microscope equipped with a digital camera (Leica DFC295) magnified by a factor of 100. Two-way analysis of variance (ANOVA) and post-hoc Tukey's HSD test were conducted to analyze the significance of crown marginal fit regarding the finish line configuration and the fabrication system. RESULTS. The mean marginal gap of lithium disilicate glass ceramic crowns (IPS e.max$^{(R)}$press) was significantly lower than that of the CAD-CAM anatomic contour zirconia crown system (Prettau$^{(R)}$Zirconia) (P<.05). Both fabrication systems and finish line configurations significantly influenced the absolute marginal discrepancy (P<.05). CONCLUSION. The lithium disilicate glass ceramic crown (IPS e.max$^{(R)}$press) had significantly smaller marginal gap than the CAD-CAM anatomic contour zirconia crown system (Prettau$^{(R)}$Zirconia). In terms of absolute marginal discrepancy, the CAD-CAM anatomic contour zirconia crown system (ZENOSTAR$^{(R)}$ZR translucent) had under-extended margin, whereas the CAD-CAM anatomic contour zirconia crown system (Prettau$^{(R)}$Zirconia) and lithium disilicate glass ceramic crowns (IPS e.max$^{(R)}$press) had overextended margins.

• Asian Journal for Public Opinion Research
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• v.5 no.3
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• pp.228-249
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• 2018

In 2015, the population of elderly people in Thailand was 16% of the total population and is predicted to be over 20% by 2021 and nearly 28% by 2031. The increase of the elderly population in Thailand has also increased the proportion of dependent elderly people, and caring for them poses many challenges for both families and the government. This descriptive method research aimed to survey the health status of dependent older people in the rural community of Lampang province in northern Thailand. The participants consisted of 62 older people and 62 primary family caregivers from Hong Ha Health Promoting Hospital, Lampang, Thailand (totaling 124 people). The researchers assessed the health status of older people and their activities of daily living (ADL). In addition, researchers assessed the health status and stress of caregivers. All the participants were interviewed about their experiences with caregiving. The results showed that most of the older respondents were female with an average age of 78.15 years. Based on the ADL assessment, 50 of the 62 older persons were homebound while the rest were bedridden. The majority of older people had chronic or long-term conditions that required hospitalization from time to time. Their frequent health problems included oral disorders such as tooth decay or caries/gum disease/no teeth, reduced sight, psychological disorders, knee pain and risk of falling, low BMI, risk of malnutrition, and urinary leakage and incontinence (58.06%, 66.13%, 62.90%, 70.97%, 38.71%, 66.13%, and 37.10%, respectively). Usual care provided by the family members included personal hygiene care, food preparation and feeding, medication management, housekeeping and organizing necessary equipment, supply of needed equipment, prevention of falls, helping with travel for medical checkups and treatment, and providing companionship. Families experienced shortages of medical supplies, daily use equipment, lack of employment, inadequate income, and difficulty accessing health care services due to lack of transportation. Some caregivers experienced caregiving stress related to a lack of social interactions as well as routine caregiving activities. Families need different types of support in order to promote the well-being of older people and caregivers. This highlights the need for a community participation model for the care of older people in order to reflect sustainable long-term outcomes.

• The korean journal of orthodontics
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• v.41 no.6
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• pp.384-398
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• 2011

Objective: The purpose of this study was to analyze the stress distribution and the displacement pattern of mandibular anterior teeth under various intrusive force vectors according to the position of orthodontic miniscrews and hooks, using three-dimensional finite element analysis. Methods: A three-dimensional finite element model was constructed to simulate mandibular teeth, periodontal ligament, and alveolar bone. The displacement of individual tooth on three-dimensional planes and the von Mises stress distribution were compared when various intrusion force vectors were applied. Results: Intrusive forces applied to 4 mandibular anterior teeth largely resulted in remarkable labial tipping of the segment according to the miniscrew position. All 6 mandibular anterior teeth were labially tipped and the stress concentrated on the labiogingival area by intrusive force from miniscrews placed mesial to the canine. The distointrusive force vector led to pure intrusion and the stress was evenly distributed in the whole periodontal ligament when the hook was placed between the central and lateral incisors and the miniscrew was placed distal to the canine. Conclusions: Within the limits of this study, it can be concluded that predictable pure intrusion of the 6 anterior teeth segment may be accomplished using miniscrews placed distal to the canine and hooks located between the central and lateral incisors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6611-6617
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• 2015

The purpose of this study is to compare the marginal and internal fit of metal and zirconia coping which is fabricated by manual and CAD/CAM(Computer Aided Design/Computer Aided Manufacturing). The model is prepared with Urethane material and two abutment teeth are fabricated with a knife and chamfer margin. Silicon replica technique is used to measure the marginal fit of manually fabricated and the CAD/CAM coping. Internal fitting level is measured with a microscope and the image is captured with a CCD camera. The distance between abutment teeth and coping is measured with a callibrated image analyzer software; marginal opening (MO), marginal gap (MG), internal gap (IG) at maximum curvature area, axial gap (AG), and occlusal gap (OG). Two-way ANOVA test is applied to compare fabrication technique and to analysis of abutment pattern. In addition, one-way ANOVA and Scheffe's test is used to analyze each parameter of the test. The result shows that the fit is < $120{\mu}m$ except OG of CAD/CAM and MO of knife margin. The CAD/CAM fabricated coping showed higher fit level at chamfer margin. However, knife margin showed better fitness compared to chamfer margin at MG. AG showed the minimum dimension with a constant result (< $38{\mu}m$).

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.2
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• pp.245-257
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• 1998

This study was performed to measure the changes of the mandibular movement and the masticatory muscular activities - anterior temporal and masseter muscle of both side - reflected by intentional increase of anterior guidance angie. For this study, 5 volunteers (3 males and 2 females with average age of 24.0) were selected. Each volunteer had Angle's classification I and did not have any missing tooth except third molar and any extensive restorations. Metallic guide plate was made at volunteer's working model fabricated by improved dental stone and cemented to the palatal surface of maxillary central incisor using resin cement(Panavia $21^{(R)}$) and then adjusted not to give any occlusal interferences at intercuspal position. The activity of masticatory muscles and the changes of mandibular movement were recorded by EMG and Sirognathograph in Biopak analysing system(Bioresearch Inc., Milwaukee, Wisconsin, USA). Measurement was done at before experiment, immediatley after placement, 1 week after placement, immediately after removal, and 1 week after removal. The results were as follows: 1. Moderate phonetic disturbance and mild headache were occured to 3 volunteers for 2 days after setting and 1 volunteer had positive reaction to percussion and slight midline diastema. But all of these clinical signs were diappeared 1 week after removal and the other volunteer did not have any special clinical sign. 2. In the EMG of the mandibular rest position, the mean value of anterior tempotal muscle was increased immediately after placement(p<0.01) and then decreased 1 week after placement(p<0.05) and increased 1 week after removal(p<0.05) but not recovered as before experiment. The mean value of masseter muscle was decreased during the experiment period. 3. In the EMG during mandibular protrusive movement, all muscular activity was decreased during the experiment period. Reduced activity was not recovered 1 week after removal(p<0.03). 4. During the habitual opening, anteroposterior movement of mandible was decreased immediately after placement(p<0.05) and then increased 1 week after placement but not statistically significant(p>0.1). Vertical movement was not shown significant difference during the experiment period(p>0.1). Lateral movement was decreased immediately after placement(p<0.05) and then increased 1 week after placement but not recovered as before experiment. The opening and closing velocity of mandible was shown minor changes but not statistically significant. 5. During the habitual opening, anteroposterior movement of mandible was decreased 1 week after placement(p<0.05) and then increased immediately after removal and recovered 1 week after removal as before experiment. Vertical movement was not shown significant changes. Lateral displacement of mandible was increased continuously and recovered 1 week after removal. Opening velocity was temporarily increased immediately after removal but recovered and closing velocity was not shown significant changes. 6. During the right side chewing, anteroposterior movement of mandible was increased immediately after removal but recovered and vertical movement was not shown statistically significant results. Lateral displacement and velocity of mandible were not shown significant results. 7. During the left side chewing, the changes of mandibular movement pattern were not shown statistically significant results.