• The Journal of Advanced Prosthodontics
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• v.9 no.6
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• pp.416-422
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• 2017

PURPOSE. To investigate the effect of reducing tooth preparation and ceramic thickness on fracture resistance of lithium disilicate crowns. MATERIALS AND METHODS. Specimen preparation included a standard complete crown preparation of a typodont mandibular left first molar with an occlusal reduction of 2 mm, proximal/axial wall reduction of 1.5 mm, and 1.0 mm deep chamfer (Group A). Another typodont mandibular first molar was prepared with less tooth reduction: 1 mm occlusal and proximal/axial wall reduction and 0.8 mm chamfer (Group B). Twenty crowns were milled from each preparation corresponding to control group (n=5) and conditioned group of simultaneous thermal and mechanical loading in aqueous environment (n=15). All crowns were then loaded until fracture to determine the fracture load. RESULTS. The mean (SD) fracture load values (in Newton) for Group A were 2340 (83) and 2149 (649), and for Group B, 1752 (134) and 1054 (249) without and with fatigue, respectively. Reducing tooth preparation thickness significantly decreased fracture load of the crowns at baseline and after fatigue application. After fatigue, the mean fracture load statistically significantly decreased (P<.001) in Group B; however, it was not affected (P>.05) in Group A. CONCLUSION. Reducing the amount of tooth preparation by 0.5 mm on the occlusal and proximal/axial wall with a 0.8 mm chamfer significantly reduced fracture load of the restoration. Tooth reduction required for lithium disilicate crowns is a crucial factor for a long-term successful application of this all-ceramic system.

• The korean journal of orthodontics
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• v.49 no.4
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• pp.205-213
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• 2019

Objective: The aim of this study was to evaluate the amount of tooth movement and histologic changes with different corticotomy designs and micro-osteoperforation in rabbits. Methods: The sample consisted of 24 rabbits divided into three experimental groups (triangular corticotomy [TC] and indentation corticotomy [IC] with flap, and flapless micro-osteoperforations [MP]) and a control. A traction force of 100 cN was applied by connecting the first premolars to the incisors. The amount of tooth movement was measured. Kruskal-Wallis test was used to assess differences in tooth movement between the groups. Micro-computed tomography, hematoxylin and eosin staining, and tartrate-resistant acidic phosphatase (TRAP) analysis were performed. Analysis of variance was applied to assess differences in TRAP-positive osteoclast count between the groups. Results: The amount of tooth movement increased by 46.5% and 32.0% in the IC and MP groups, respectively, while the bone fraction analysis showed 69.7% and 8.5% less mineralization compared to the control. There were no significant intergroup differences in the number of TRAP-positive osteoclasts. Conclusions: The micro-osteoperforation group showed no significant differences in the amount of tooth movement compared to the corticotomy groups, nor in the TRAP-positive osteoclast count compared to both corticotomy groups and control.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.179-186
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• 2023

This study investigated tooth whitening preferences among college students, evaluating their knowledge, satisfaction, aesthetic criteria, and preferences, while identifying influencing factors. Using a 28-item questionnaire covering general, tooth whitening knowledge, satisfaction, aesthetic criteria, and preference questions, 175 participants surveyed from June 7th to 10th, 2022, underwent analysis. Descriptive statistics, t-tests, analysis of variance, and regression analysis were applied. Results showed tooth whitening knowledge scored 2.90 out of 5 points, satisfaction 2.97, aesthetic criteria 3.59, and preferences 3.28. Tooth whitening knowledge was higher among female and health-related major students, while satisfaction was greater among males, non-health-related majors, and those without cosmetic procedures. Aesthetic criteria were stronger in participants with higher allowances and cosmetic procedures experience. No significant tooth whitening preference differences were found based on general characteristics. Regression analysis revealed significant impact of aesthetic criteria on tooth whitening preferences (β=0.252).

• Journal of Preventive Medicine and Public Health
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• v.52 no.5
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• pp.333-343
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• 2019

Objectives: This study aimed to evaluate the association between dental implants and cognitive function in community-dwelling older adults. Methods: Data were collected from the baseline survey (2016-2017) of the Korean Frailty and Aging Cohort Study. The study sample comprised 1115 community-dwelling people aged 70 years to 84 years who had 0-19 natural teeth. Dental implants and natural teeth were identified by panoramic radiography, while the cognitive function was assessed by the Korean version of the Mini-Mental State Examination (MMSE-KC). The association between dental implants and cognitive function was analyzed by multiple linear regression. Sensitivity analysis was performed to test for potential bias. Results: The mean number of natural teeth in the study population was 9.50 (standard deviation [SD], 6.42), and the mean MMSE-KC score was 24.93 (SD, 3.55). In the simple univariate analysis, tooth replacement, age, sex, smoking status, alcohol consumption, body mass index, osteoporosis, number of natural teeth, periodontitis, chewing discomfort, tooth-brushing frequency, education level, monthly household income, participation in economic activity, living alone, and marital status had a significant impact on the association. After adjusting for confounders, the association between dental implants and cognitive function remained significant (B, 0.85; standard error, 0.40; p<0.05). Age, body mass index, periodontitis, tooth-brushing frequency, and education level were also significantly associated with cognitive function. The results of the sensitivity analyses were consistent with those of the primary analysis. Conclusions: Dental implants were associated with cognitive function in older adults living in the community. Dental implants as tooth replacements may play a role in preserving cognitive function.

• Korean Journal of Health Education and Promotion
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• v.26 no.1
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• pp.117-128
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• 2009

Objectives: The purpose of this study was to assess the effect of mothers education attainment on prevalence of dental caries among their preschool children. Methods: Data were obtained from the third 2006 Korea National Oral Health Survey. A total of 515 preschool children aged 2 to 7 years and their mothers were selected in this study. We used mother's education level as her socioeconomic position and controlled children's tooth brushing frequency, tooth brushing before bed, the frequency of eating snack, and the preventive dental visit. Whether children experienced dental caries or not and the number of decayed or filled or missing tooth surface they had were used as outcome variables. Results: The proportion of children affected with dental caries was 46.21%. The mother's education level affected children's caries significantly (p<0.05) and children whose mother attended less than high school had more possibility of having caries than children whose mother graduated from college or more (p<0.05). This effect was still significant and got larger(p<0.05), even after controlling children's dental health behavior. Conclusion: This study showed that mother's education level affected the prevalence of caries among their preschool children. In addition, this result indicated a need for more definite policy for children's dental health in lower socioeconomic class with general dental education.

• The Journal of Korean Society for School & Community Health Education
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• v.10 no.1
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• pp.87-104
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• 2009

Objective: In this study, the dental health care knowledge, dental health behaviors and dental health status of elementary school students were compared and analyzed in the cases of their schools having dental health care center or not one. Methods: The target groups were 167 students of A school (experimental group) where pit-and-fissure sealants, fluoride mouthrinsing, and fluoride gel application were carried out with all grades of students by school dental health care center and 158 students of B school (control group) where fluoride mouthrinsing, for all grades students and pit-and-fissure sealants for the first grade students are carried out but have no the school dental health care center. Results: This study was carried out through the answer sheets and recordings of dental inspection. The findings of this study are as follows: 1. The dental health care knowledge was compared and the results showed that on average 14.2$\pm$2.1 in experimental group and 14.0$\pm$1.9 in the control group were no significantly different (p>0.05). 2. The dental health behaviors were compared and the results showed that the experimental group was significantly different(p<0.05) in terms of the number of times of dental brushing a day, the method of tooth brushing, the time of tooth brushing, the experience of tooth brushing with fluorine, the kinds of snacks and tooth brushing in school after lunch. But there was no significant difference(p>0.05) in the time of tooth brushing and the tooth brushing after eating snacks. 3. The DMF rate was compared and the results showed the significantly difference between the average experimental group and 53.8$\pm$5.0 in the control group(p<0.05). 4. The DMFT index was compared and the results showed the significantly difference between the average 0.6$\pm$2 in the experimental group and 1.4$\pm$1.6 in the control group(p<0.05). 5. The DMFI rate was compared and the results showed the significantly difference between the average 4.2$\pm$8.3 in the experimental group and 9.5$\pm$11.0 in the control group. (p<0.05). 6. The DT rate were compared and the results showed the significantly difference between the average 10.2$\pm$29.5 in the experimental group and 32.4$\pm$44.0 in the control group(p<0.05). 7. The FT rate were compared and the results showed the significantly difference between the average 88.5$\pm$31.0 in the experimental group and 67.5$\pm$44.0 in the control group(p<0.05). Conclusions: Based on the results, above there was no significant difference in dental health care knowledge between both the experimental and the control group. But we discovered that the experimental group is better than the other one in dental health care behaviors and dental health status. Therefore, we could conclude that the school dental health care center efficiently carried out the dental care and treatment. As school dental health care centers did not work out efficiently in terms of their educating on the dental health acre knowledge, the related programs to be developed and supported.

• Journal of dental hygiene science
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• v.21 no.3
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• pp.185-197
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• 2021

Background: This study aimed at investigating the meal regularity, health, and oral health habits of single Korean households to understand the impact of these factors on the risk of metabolic syndrome, in addition to preventing and managing metabolic syndrome. Methods: Using raw data from the 8th Korea National Health and Nutrition Examination Survey (2019), 274 study subjects, aged 19 to 64, were selected primarily from single adult households. Complex sample statistical analysis was performed using the Predictive Analytics Software Statistics ver. 18.0 program. Results: Regarding the meal regularity in single-person households in Korea, the younger group outperformed the middle-aged group, and those who drank more than once a month performed better than those who drank less than once a month. In terms of oral health, regardless of the age and the income level, participants who ate three meals a day had a higher rate of speech problems and chewing difficulties than those who ate irregularly or regularly on a regular day. Factors influencing the risk of developing metabolic syndrome were age, speech problems, and frequency of toothbrushing. Compared to the younger group, there were 0.361 times more people in the middle-aged group; and compared to those without speech problems, there were 1.161 more people with speech problem. Compared to those who tooth brushed more than four times a day, there were 1.284 more people who tooth brushed 2 to 3 times a day and there were 5.673 times more people who tooth brushed less than once. Conclusion: Based on the study results, it is necessary to implement a program that can plan and apply customized management measures and prevent metabolic syndrome by improving and correcting the health and oral health behaviors of single-person households in Korea. Therefore, active mediation measures, such as support and publicity at the local or national level, should be planned.

• Journal of agricultural medicine and community health
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• v.21 no.1
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• pp.75-84
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• 1996

This study was conducted to reveal the relationship between the oral health status and their Knowledges about the oral health of the freshman of colleges in Taegu city. The evaluation for the oral health status through the oral examinations and their analysis of their knowledges on the periodontal disease were done on 216 males and 205 females from 1st to 30th April, 1993. The obtained results were as follows: The oral health status of 421 subject showed that 35.7% was good, 59.1% fair, and 6.2% poor, respectively. In case of the oral health status of females, 41.9% was good and 4.4% poor, and then in males 27.8% was good, 7.8% poor. The oral health status of the females was better than that of the males(p=0.006). The 52.1% among the good oral health status group answered that the dental plaque is the bacterial membrane causing dental disease, and the 23.1% among the poor oral health status group answered same as the above. The 91.8% among the good oral health status group answered that the periodontal diseases can be prevented, and the same answer came out from 15.4% of the poor group. It was found that the better oral health status group had the better knowledges about periodontal disease(p=0.001). For the question about their experiences in scaling the 30.1% of good oral health status group and the 23.1% of poor group answered that scaling is very helpful to periodontal health(p=0.001). About the experience of the education for tooth brushing, the 53.2% of good oral health status group and the 7.6% of poor group had the experiences to receive the education for tooth brushing(p=0.001). About the frequency and the time of tooth brushing, the 53.4% of good oral health status group brushed their teeth more then 3 times a day and 41.8% of good group brushed their teeth after every meal(p=0.001). The result of multiple regression analysis according to the simplified oral health index indicated that the variable having an effect on the oral health status was the tooth brushing frequency, knowledge of periodontal disease prevention, experience in education of tooth brushing and time of tooth brushing(p=0.001).

• The Korean Journal of Health Service Management
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• v.6 no.2
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• pp.15-23
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• 2012

In this study, oral health promotion behaviors of employees, daily frequency of tooth brushing, tooth brushing method, brushing time, whether or not to use oral hygiene accessories, and regular dental check-up to investigate oral health status of workers to the workplace and was to provide basic data for the development of oral health program to promote oral health. This study was performed from 2011 May 2 to May 20, 249 industrial workers in Ulsan metropolitan city surveyed and collected data using PASW 18.0 ver, descriptive statistics, Pearson's chi-square test was performed. In the result, the importance of oral health recognition was lacked, in order to maintain and promote the oral health status of industrial workers, regular dental check-up on oral health counseling and oral health education were conducted together and raising awareness of workers' oral health was necessary to improve level of oral health status.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.2
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• pp.143-152
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• 2023

Although tooth wear is a normal process due to aging, severe tooth wear causes various complications such as increased tooth sensitivity, loss of tooth structure, and pulp complications. In the treatment of patients with excessive tooth wear, the evaluation of loss of vertical occlusal dimension should be prioritized. If it is necessary to increase the vertical dimension to secure the restoration space, it is important to establish a treatment plan with the comprehensive analysis and determine the minimum vertical dimension elevation. In this case, 66-year-old male patient with severe worn dentition wanted to restore masticatory function and improve esthetic restoration. In order to determine the appropriate vertical dimension of the patient, we evaluated oral examination, radiographic examination, and diagnostic cast examination, and performed rehabilitation with minimum vertical dimension elevation. As a result of observation for 8 months, the definitive prosthesis was completed with contact of all teeth in centric occlusion, and proper anterior/posterior guidance. Through the above process, satisfactory aesthetic and functional outcomes were obtained.