• Journal of dental hygiene science
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• v.13 no.2
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• pp.135-141
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• 2013

One factor for successful prognosis of finished dental prosthesis is good marginal fit. The purpose of this study in vitro investigation was to compare the marginal fit of all-ceramic crown before and after porcelain veneering, to evaluate the influence of high temperature of the porcelain firing on the fit. For this experiment, model of abutment tooth of maxillary right central incisor was prepared. Ten working models were produced. Ten zirconia cores were made by dental computer aided design/computer aided manufacturing system. The marginal fit of specimens were examined using silicone replica technique. Silicone replicas were sectioned four times and were measured through a digital microscope (${\times}160$). Marginal fit is a distance connected between edge end part of specimen and abutment margin. Each specimens was measured twice, the first measurement was done prior to veneering porcelain firing, while the second measurement was done after the porcelain firing to evaluate this process. Statistical analyses were performed with paired t-test. $Mean{\pm}SD$ marginal fit was $60.8{\pm}14.2{\mu}m$ for zirconia core and $86.1{\pm}13.3{\mu}m$ for all-ceramic crown. They were statistically significant differences (p<0.001). But all specimens showed a marginal fit where the gap widths ranged within the clinical recommendation ($120{\mu}m$), all-ceramic crown production using the zirconia core was adequate.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.4
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• pp.196-203
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• 2022

Purpose: This study aimed to evaluate the accuracy and clinical usability of an identification model using deep learning for 79 dental implant types. Materials and Methods: A total of 45396 implant fixture images were collected through panoramic radiographs of patients who received implant treatment from 2001 to 2020 at 30 dental clinics. The collected implant images were 79 types from 18 manufacturers. EfficientNet and Meta Pseudo Labels algorithms were used. For EfficientNet, EfficientNet-B0 and EfficientNet-B4 were used as submodels. For Meta Pseudo Labels, two models were applied according to the widen factor. Top 1 accuracy was measured for EfficientNet and top 1 and top 5 accuracy for Meta Pseudo Labels were measured. Results: EfficientNet-B0 and EfficientNet-B4 showed top 1 accuracy of 89.4. Meta Pseudo Labels 1 showed top 1 accuracy of 87.96, and Meta pseudo labels 2 with increased widen factor showed 88.35. In Top5 Accuracy, the score of Meta Pseudo Labels 1 was 97.90, which was 0.11% higher than 97.79 of Meta Pseudo Labels 2. Conclusion: All four deep learning algorithms used for implant identification in this study showed close to 90% accuracy. In order to increase the clinical applicability of deep learning for implant identification, it will be necessary to collect a wider amount of data and develop a fine-tuned algorithm for implant identification.

• Journal of Oral Medicine and Pain
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• v.36 no.3
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• pp.147-160
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• 2011

Eugenol (4-allyl-2-methoxyphenol) is a natural phenolic constituent extensively used in dentistry as a component of zinc oxide eugenol cement and is applied to the mouth environment. Chios gum mastic (CGM) is a resinous exudate obtained from the stem and the main leaves of Pistacia lenticulus tree native to Mediterranean areas. This study was undertaken to investigate the synergistic apoptotic effect of co-treatment with a natural product, CGM and natural phenolic compound, eugenol on SCC25 human tongue squamous cell carcinoma cell line. To investigate whether the co-treatment with eugenol and CGM compared to each single treatment efficiently reduces the viability of SCC25 cells, MTT assay was conducted. Induction and augmentation of apoptosis were confirmed by Hoechst staining, TUNEL staining and DNA hypoploidy. Westen blot analysis and immunofluorescent staining were performed to study the alterations of the expression level and the translocation of apoptosis-related proteins in co-treatment. In this study, co-treatment of with eugenol and CGM on SCC25 cells showed several lines of apoptotic manifestation such as nuclear condensations, DNA fragmentation, the increase and decrease of Bax and Bcl-2, decrease of DNA content, the release of cytochrome c into cytosol, translocation of AIF and DFF40 (CAD) onto nuclei, and activation of caspase-3, caspase-6 caspase-7, caspase-9, PARP, Lamin A/C and DFF45 (ICAD) whereas each single treated SCC25 cells did not show or very slightly these patterns. Although the single treatment of 40 ${\mu}g$/ml CGM and 0.5 mM eugenol for 24 h did not induce apoptosis, the co-treatment of these reagents prominently induced apoptosis. Therefore our data provide the possibility that combination therapy with CGM and eugenol could be considered as a novel therapeutic strategy for human oral squamous cell carcinoma.

• Journal of dental hygiene science
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• v.6 no.3
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• pp.207-212
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• 2006

In parallel with social and economic progress, motives of patients to consult dentists have increased and diversified. An increasing number of people visit dental clinics to improve their facial appearance and masticating functions deteriorated largely due to malocclusion. There is also greater interest in and concern as well as demand for teeth alignment treatment among people. Under this situation, it is required to find and suggest ways to enhance quality and profitability of dental care in view of managerial needs for dentists to cope with changing circumstances. This study, thus, aims to measure satisfactions of orthodontics patients and to determine the elements influencing their satisfactions. For this aim, a survey was performed for 20 days from March 7th to 26th, 2005 by means of questionnaires distributed to randomly selected samples, resulting in following conclusions: 1. From comparison of satisfactions with dental service by their elements, higher satisfaction was reported from orthodontics patients in the element of dental hygienists(4.21). Least satisfaction, however, was found in the procedure for treatment and waiting hours(3.73). 2. By gender, male orthodontics patients turned out to be more satisfactory with dental service than females. In terms of intention for return visits, both male and female orthodontics patients showed higher satisfaction than non-orthodontics ones. 3. As for satisfaction with dental service by age of orthodontics and non-orthodontics patients, with regard to intention for return visit, orthodontics patients of all ages showed to have higher grade of satisfaction. 4. Regarding satisfaction with dental treatment by orthodontics and non-orthodontics patients by monthly income, Dental hygienist with intention for return visit, the higher the satisfaction of orthodontics patients. 5. In regard to satisfaction with dental treatment by education, higher satisfaction was expressed by orthodontics patients with elementary school education kept dentist, dental hygienist and internal and external environments. As a result from this study, we knew that dental service of the orthodontics patients is higher satisfaction than that of the non-orthodontics patients.

• Journal of the Korea Society of Computer and Information
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• v.27 no.6
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• pp.131-137
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• 2022

As the age increases, the oral cavity, that is, the teeth and periodontium, also begin to age, and accordingly, a preparation process is required. The preparation process is an important period for oral health management to start continuously with oral health education consisting of knowledge, attitude, and behavior from the 20s. Therefore, to design a clinical dental hygiene course for patients who visited a dental clinic in Gyeonggi-do and received continuous care in an oral health care room after treatment, we tried to analyze the data of the dental hygiene assessment. As a dental hygiene assessment tool, based on personal information and general medical history, dental visit experience, bleeding on probing(BOP), bad breath measurement, phase contrast microscopy, and O'Leary index were performed. The number of subjects who had dental visits was 75.4% and those without experience were 24.6%, and as a result of the periodontal examination, generally bleeding was found in 76.3%. In preventive oral care, the stage of dental hygiene assessment in the 20s is an important first step. From this point on, it is an important time to be systematically habituated so that you can take responsibility for your own oral condition. Therefore, in this study, the results of dental hygiene assessment through oral examinations of subjects in their 20s are derived and presented as basic data for the development of dental hygiene performance competency of dental hygienists during the clinical dental hygiene process in oral health education and oral health management.

• Journal of Oral Medicine and Pain
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• v.30 no.2
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• pp.215-230
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• 2005

The study was intended to investigate how dentists in private dental clinic thought on the present claim and review of dental insurance to reflect it in future establishing dental insurance policies. 1,465 dentists who were running own dental clinic in Pusan Metropolitan City and the south part of Kyungsang province were surveyed in February, 2004. A total of 406 copies of finished questionnaire were finally retrieved and analyzed. The findings are as follows. 1. About insurance claim affairs : Most of the subject of insurance claim was by dentist himself or dental hygienist(nurse). Agency claiming was carried under 20% of total insurance claim. 2. The degree of attendance on insurance lecture : The degree of attendance on insurance lecture was relatively low. 3. Filing a protest against insurance claim : Filing a protest against insurance claim was reavealed about half-and-half for "have been" or "have not been". 4. Private clinic dentist,s opinion about the regulations affecting review of dental insurance : Private clinic dentists opinion about current guide for insurance review of dental fee was“the guidance is difficult and unfair cutback of claim fee may be carried”. 5. The affairs about health insurance review agency : About 70% of private clinic dentists have dissatisfaction on health insurance review agency. 6. Standpoint of private clinic dentists about issuance of receipt for dental fee : About 70% of private clinic dentist have an difficulty in issuance of receipt for dental fee. 7. The affairs about change insurance noncoverage treatment to insurance coverage treatment : Most of private clinic dentists hoped that insurance coverage about full mouth scaling, pit and fissure sealant, fluoride application. But they do not hoped that insurance coverage about geriatric denture, prothodontic treatment except precious metal, photopolymerization resin treatment.

• Journal of dental hygiene science
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• v.6 no.1
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• pp.23-28
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• 2006

This study was conducted to investigate the oral health related quality of life in elders concerning to residence at urban and rural. The subjects were 215 old persons who were over the 60 years old, living at Sahagu in Busan(113persons) and Geojer Si in Kyungnam (102persons). The data for this study were collected by direct interviewing method from May 30 th to June 30 th and September 12 th, 2005. Cushing & Sheiham's Sociodental Scale which measures oral health related quality of life was used for this study. The data were analysed by a computerized program named statistical package for social science including frequency, percentage, t-test. The results of this study were summarized as follows; 1. Mean score of the oral health related quality of life in elders is $2.42{\pm}1.03$ 2. There was a significant difference in oral health related quality of life in elders between the age 60 ~ 70 years group and the over than 71 years group(P < 0.01). 3. There was a significant difference in oral health related quality of life in elders between the urban and rural group(P < 0.05). Above findings suggest that further study about proper program for geriatric oral health evaluation is necessary in improving the oral health related quality of life in elders.

• The korean journal of orthodontics
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• v.36 no.2 s.115
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• pp.161-169
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• 2006

The purpose of this study was to investigate cephalometrically the short term static velopharyngeal changes in 25 patients (10 boys and 15 girls, aged from 5 years 9 months to 12 years 10 months in the beginning of treatment) with skeletal Class III malocclusions who underwent nonsurgical maxillary protraction therapy with a facemask. The linear, angular and ratio measurements were made on lateral cephalograms. Only the change in hard palatal plane angle was negatively correlated with the change in maxillary depth or N-perp to A (p<0.01). The change in velar angle showed a statistically significant increase (p<0.001). This change was influenced more by the soft palatal plane angle than by the hard palatal plane angle (p<0.001). The changes in soft tissue nasopharyngeal depth and hard tissue nasopharyngeal depth showed statistically significant increases (p<0.001). Correlations between the changes in soft tissue (or hard tissue) nasopharyngeal depth and the change in soft palatal plane angle were significant (p<0.05). The increase in hard palate length was statistically significant (p<0.001). The change in hard palate length was negatively correlated with the change in soft tissue nasopharyngeal depth (p<0.05). The change in need ratio S (C) showed a statistically significant increase (p<0.001). But this difference was within the normal range reported by previous studies. These findings indicate that the velopharyngeal competence was maintained even if the anatomical condition of the static velopharyngeal area were changed after maxillary protraction.

• The Korean Society of Law and Medicine
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• v.22 no.3
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• pp.97-124
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• 2021

In medical institutions, there are radiation-related workers such as radiological technologists, physicians, dentists, and dental hygienists who handle diagnostic radiation generators. Also, there are work assistants, such as nurses and assistant nurses, who assist in radiation treatment or transfer patients to the radiation examination room. Radiation exposure management for radiation-related workers is carried out under the 「Medical Service Act」, but there is no legal basis for work assistants, etc. And the management of radiation exposure for diagnosis is regulated by the 「Medical Service Act」, and the management of radiation exposure by therapeutic radiation and nuclear medical examination is governed by the 「Nuclear Safety Act」. Thus, to improve the management of radiation exposure for diagnosis, the regulations on radiation exposure management for diagnosis under the 「Medical Service Act」 were compared and reviewed with those of the 「Nuclear Safety Act」. As a result, the main contents are as follows. First, it is necessary to legislate to include nurses, assistant nurses, and clinical practice students who are likely to be exposed to radiation besides radiationrelated workers as subjects of radiation exposure management for diagnosis. Second, when a radiation-related worker for diagnosis is confirmed to be pregnant, the exposure dose limit should be defined. Third, it is necessary to revise the regulations on the types of personal exposure dosimeters in the 「Rules on the Safety Management of Radiation Generators for Diagnostics」. Fourth, it seems that health examination items for radiation-related workers, radiation workers, and frequent visitors should be the same. Fifth, It is necessary to unify and regulate diagnostic radiation and all medical radiation, including therapeutic radiation and nuclear medicine, in one legal system.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.1
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• pp.42-51
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• 2022

Esthetic restoration of maxillary anterior implant heavily depends on the direction of installation of implant fixture. In patients with malpositioned implant, it is crucial to communicate the limitations of prosthetic outcome with the patient before starting on a restoration. To facilitate the communication, three-dimensional virtual representation by superimposing facial and intraoral digital scans with Computed Tomography (CT, dicom file) was used for visualization of the limitations of prosthesis. Through digital diagnostic wax-up, the profile of right maxillary anterior incisor implant was expected to be protrusive, which the patient was not satisfied with. Since the patient already had done root canal treatment on left maxillary anterior incisor due to previous trauma, a new prosthetic design including both right and left maxillary anterior incisors was presented to the patient. The second design was chosen and his comments were delivered to dental lab. The patient was satisfied with the new prosthesis, aesthetically and functionally.