• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.316-321
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• 2020

PURPOSE. The stress distribution and microgap formation on an implant abutment structure was evaluated to determine the relationship between the direction of the load and the stress value. MATERIALS AND METHODS. Two types of three-dimensional models for the mandibular first molar were designed: bone-level implant and tissue-level implant. Each group consisted of an implant, surrounding bone, abutment, screw, and crown. Static finite element analysis was simulated through 200 N of occlusal load and preload at five different load directions: 0, 15, 30, 45, and 60°. The von Mises stress of the abutment and implant was evaluated. Microgap formation on the implant-abutment interface was also analyzed. RESULTS. The stress values in the implant were as follows: 525, 322, 561, 778, and 1150 MPa in a bone level implant, and 254, 182, 259, 364, and 436 MPa in a tissue level implant at a load direction of 0, 15, 30, 45, and 60°, respectively. For microgap formation between the implant and abutment interface, three to seven-micron gaps were observed in the bone level implant under a load at 45 and 60°. In contrast, a three-micron gap was observed in the tissue level implant under a load at only 60°. CONCLUSION. The mean stress of bone-level implant showed 2.2 times higher than that of tissue-level implant. When considering the loading point of occlusal surface and the direction of load, higher stress was noted when the vector was from the center of rotation in the implant prostheses.

• Journal of Korean society of Dental Hygiene
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• v.12 no.5
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• pp.909-919
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• 2012

Objectives : The purpose of this study was to examine the impact of the self-efficacy of dental hygienists on their stress-coping method. Methods : The subjects in this study were the dental hygienists in dental institutions that were selected by convenience sampling from Jeonju, Iksan, Gimjei and Gunsan in North Jeolla Province. A survey was conducted by using structured questionnaires. Results : A regression analysis was carried out to see whether self-efficacy would affect stress-coping method, and it's found that those whose overall self-efficacy was better made more use of an overall stress-coping method(p>0.001). General and social self-efficacy exerted a significant influence on a problem-oriented stress-coping method(p>0.001, p>0.01), and general and social self-efficacy had an impact on a stress-coping method of social support pursuit(p>0.01, p>0.01). In addition, general and social self-efficacy exercised an influence on a stress-coping method of wishful thinking(p>0.01, p>0.05). Conclusions : The self-efficacy of the dental hygienists affected their own stress-coping method, and the finding of the study suggests that a lot of efforts should be made from diverse angles to boost the self-efficacy of dental hygienists.

• Journal of Korean society of Dental Hygiene
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• v.10 no.6
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• pp.973-981
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• 2010

Objectives : The purpose of this study is to find out factors that affect turnover intention among dental hygienists. This study also provides a method to decrease the turnover intention, and demonstrates plans to improve organizational effectiveness. Methods : The data was collected from 300 dental hygienists working at dental clinics in Daegu and Kyungbuk province during the month of September, 2010. The total of 152 copies were used for analysis. The questionnaires were consisted of 6 categories: turnover intention, empowerment, organizational commitment, burnout, stress, and job satisfaction. T-test, ANOVA, correlation analysis, multiple regression were applied in this analysis. Results : 1. Looking at the relations between turnover intention and general characteristics, urnover intention was the highest among 20-29 age group, junior college graduates, and the group that had lees than 2-5 years of working experiences(p<0.05). Regarding marital status, singles had higher turnover intention than married people. 2. Looking at the correlation among turnover intention, empowerment, organizational commitment, burnout, stress, and job satisfaction, most of these factors showed significant correlations. However the correlations between organizational commitment and stress, stress and empowerment, stress and job satisfaction were not significant(p<0.05). 3. Organizational commitment and stress had significant influence on turnover intention(p <0.05). Organizational commitment was the most significant factor and it negatively influences the turnover intention. Conclusions : In order to decrease the turnover intention among dental hygienists, plans that can increase the organizational commitment should be implemented by improving organization-related factors.

• Journal of Technologic Dentistry
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• v.40 no.1
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• pp.41-47
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• 2018

Purpose: The purpose of this study was to analyze the biomechanical properties of the dental implants on the supporting bone using three-dimensional finite element method when three different abutment materials were applied to the implant system. Methods: Three different dental implant models were fabricated by applying Ti, PEEK, and CRE-PEEK (60% carbon-reinforced PEEK) to abutment material. The abutment and connecting screw from the fixture was applied with a tightening torque of 20 Ncm. And then, total loads of 150 N were applied in an $30^{\circ}oblique$ direction (to the vertical). The structural stability of dental implants on the supporting bone was analyzed using Von Mises stress and principal stress values. Results: The maximum tensile stress of the cortical bone was highest at 12.6 MPa in the PEEK abutment (Model-B). Ti abutment (Model-A) and CRE-PEEK abutment (Model-C) showed similar stress distributions (10.6 and 10.3 MPa, respectively). And the maximum compressive principal stress was similar in all models. The Von Mises stress value delivered to the bone around the implant was highest at 16.5 MPa in Model-B. On the other hand, Model-A and C showed similar stress distributions (14.0 and 13.8 MPa, respectively). In addition, the maximum equivalent stress applied to the abutment was highest at 629.8 MPa in Model-A. The stress distribution in Model-C was 573.9 MPa. Whereas, Model-B showed the lowest value at 165.6 MPa. Conclusion : The dental implant supporting bone system using PEEK material seems to have the possibility of supporting bone fracture. It was found that the CRE-PEEK abutment can reduce the elastic deformation and reduce the stress value of the interfacial bone.

• Journal of Convergence for Information Technology
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• v.11 no.9
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• pp.191-200
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• 2021

This study systematically collected and analyzed the results of previous studies on the stress of clinical dental prctice for dental hygiene students. The data were collected according to the systematic review guidelines of PRISMA(Preferred Reporting Items for Systematic Reviews and Meta-analysis) and 25 ariticles were used in the final analysis. In order to measure clinical dental practice, 4 measuring tools were used. As a result of literature analysis, the lower the satisfaction, the higer the stress of clinical dental practice. Personal relationship, role and activity, ideal and value were very important factors. The purpose of this study is to analyze the relationship between clinical dental practice and various variables and to investigate the improvement of clinical dental practice based on the results of this study.

• Journal of Technologic Dentistry
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• v.38 no.3
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• pp.151-156
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• 2016

Purpose: The dental implant should be enough to endure chewing load and it's required to have efficient design and use of implant to disperse the stress into bones properly. This study was to evaluate the stress distribution on a supporting bone by lengths and diameters of the implant fixture. Methods: The modeling and analysis of stress distribution was used for the simple molar porcelain crown model by Solidworks as FEM program. It was designed on applying with tightening torque of 20 Ncm of a abutment screw between a cement retained crown abutment and a fixture. The fixtures of experimental model used 10, 13mm by length and 4, 5mm by diameter. A external vertical loading on the two buccal cusps of crown and performed finite element analysis by 100 N. Results: The maximum von Mises stress(VMS) of all supporting bone models by fixture length and diameter were concentrated on the upper side of supporting compact bone. The maximum stress of each model under vertical load were 164.9 MPa of M410 model, and 141.2 MPa of M413 model, 54.3 MPa of M510 model, 53.6 MPa of M513 model. Conclusion: The stress reduction was increase of fixture's diameter than it's length. So it's effective to use the wider fixture as possible to the conditions of supporting bone.

• Journal of Korean society of Dental Hygiene
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• v.19 no.2
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• pp.241-249
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• 2019

Objectives: This study aimed to investigate the effects of verbal violence experience on stress and positive psychological capital as well as the mediating effects of positive psychological capital. Methods: A survey was conducted with dental hygienists working at university hospitals, general hospitals, and dental hospitals and clinics in Busan, Gyeongnam, and Ulsan areas.Of the 230 questionnaires distributed, 206 were used in the analysis after excluding 24 completed questionnaires that had errors or missing answers. Results: As a result of identifying the relationships between verbal violence damage, positive psychological capital, and stress, verbal violence damage was negatively correlated with positive psychological capital (r=-0.28, p<0.001) and positively correlated with stress (r=0.40, p<0.001). Positive psychological capital had a negative correlation with stress (r=-0.25, p<0.001). As a result of verifying the mediating effects of positive psychological capital on the relationship between verbal violence damage and stress among dental hygienists, it was found that verbal violence had a significant effect on stress and positive psychological capital in the first and second stages. In the third stage, the effect of positive psychological capital on stress was significant, showing that there was a mediating effect. Conclusions: Therefore, sound work environments should aim to reduce verbal violence while increasing support systems to reduce negative emotional and psychological states.

• Journal of Korean society of Dental Hygiene
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• v.11 no.3
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• pp.343-351
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• 2011

Objectives : The aim of this study was to investigate factors associated with turnover intention on public health dental hygienists. Methods : A total 235 public health dental hygienist completed a questionnaire on attitudes related to their job position and sociodemographic status. Results : In total 82.5% of the respondents have experienced a job transfer. Their children and job stress strongly affect turnover intention. Turnover intention was correlated with empowerment, organizational commitment, job satisfaction, burnout and job stress. Using multiple regression analysis, the effects of job stress, children, organizational commitment, job satisfaction, career were satistically significant. Conclusions : The study showed strong relationship between turnover intention and job stress and their children. They had positive attitude for their job position and satisfied with their job. They experienced the stress on their job but had little turnover intention.

• Journal of Korean society of Dental Hygiene
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• v.13 no.5
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• pp.855-861
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• 2013

Objectives : This study aims to investigate the relationship between the self-leadership and stress of students majoring in dental hygiene in clinical practice. This study will be helpful to cope with clinical practice effectively. Methods : Subjects were 221 dental hygiene students from 4 universities in Daegu and Gyeongbuk. Data were abalyzed by independent t-test and multiple regression analysis. Results : Stress-response was 60.36 points in high self-leadership group and 57.20 points in kow self-leadership group. It was statistically significant. Clinical practice-induced stress was made by self-expectation, rehearsal, and self-criticism. Stress was able to be overcome by self-reward and positive mind. Conclusions : It is necessary to take the curriculum into consideration which can improve the self-leadership before the clinical practice or at the early phase of clinical practice in order to ensure that the students majoring in dental hygiene are exposed to less stress arising from clinical practice and better cope with such stress.

• Journal of Korean society of Dental Hygiene
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• v.8 no.4
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• pp.65-77
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• 2008

The purpose of this study was to offer basic data in order to make it possible for becoming the mentally more matured dental hygienist by being aware of stress factors on employment in preliminary dental hygienists and examining a coping plan according to it. The self-administered questionnaire research was carried out targeting Dental Hygiene Students at 4 colleges in metropolitan area for 1 month from October to November in 2007. Totally 209 questionnaires were collected. Among them, 206 copies were analyzed with methods in frequency analysis, correlation analysis, and ANOVA analysis by using SPSS WIN10.0 statistical program. As a result, the following conclusions were obtained. 1. 84.5% out of subjects were the active students. 95.2% and over 95.6%, respectively, were surveyed to be more than 'moderate' as for the academic achievement level and the satisfaction with college life. 2. the majority in the survey subjects were researched to receive high stress as for 'a guiding professor doesn't lead and have interest in my employment, thereby being disappointing' and 'failing to be employed is likely to lead to hurting pride so much'. 3. a coping type with stress in the survey subjects was researched to select a coping plan much as for 'sincerely hoping for the work to be well done', 'going out for a change', 'establishing a few countermeasures for solving a problem', 'overeating', and 'waiting while thinking it to be solved some time.' 4. most of stress factors had high correlation with a coping type with saying of 'trying to be alone as a whole', and had high correlation with 'failing to be employed is likely to lead to hurting pride so much' and 'overeating'. Even additionally, it was surveyed to have high correlation with 'smoking' and 'depending on the past experience'.