• The Journal of the Korean dental association
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• v.54 no.5
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• pp.374-383
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• 2016

The purpose of this study is to analyze the determinants of pay satisfaction of dental employees. The questionnaire used in this study consists of personal characteristics, characteristics of workplace, administration of pay, Pay satisfaction questionnaire (PSQ). PSQ was translated, and backward translation into korean was implemented. A pilot test was conducted with 25 dental employees to complete the questionnaire. Survey was conducted from February to July in 2015, receiving 323 valid responses. Anova or t-test was conducted with categorized characteristics, by calculating pay satisfaction scores. Principal factor analysis which is an exploratory factor analysis was conducted to investigate the consistency of pay satisfaction. Multiple regression analysis was conducted to investigate how much effect the variables have on pay satisfaction. The result of principal factor analysis showed that pay satisfaction consists of 3 factors which are 'paying system', 'pay level', 'benefits'. 'Pay raise' which was one of 4 factors of original PSQ was not the factor of pay satisfaction of dental employees. The result of analysis of characteristics showed that the scores of paying system between dental clinic and dental hospital had significant difference. The result of multiple regression analysis showed tendencies pay satisfaction increases when age and monthly income increases and whole career and the number of unit chairs decreases. Increasing the autonomy of employees and simplification of paying system would improve pay satisfaction efficiently. When age increases, the pay level increases because of the seniority-based pay structure, and this leads to the higher satisfaction. The higher amount of pay leads to higher satisfaction. The expectation over pay increases relatively higher than the increase of pay level and this leads to the less satisfaction. When the number of unit chairs is fewer, the workplace is smaller, so the employees have more autonomy, and this leads to higher satisfaction.

• Journal of Periodontal and Implant Science
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• v.47 no.4
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• pp.194-210
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• 2017

Purpose: The aim of the present study was to evaluate the healing of post-extraction sockets following alveolar ridge preservation clinically, radiologically, and histologically. Methods: Overall, 7 extraction sockets in 7 patients were grafted with demineralised bovine bone mineral and covered with a porcine-derived non-crosslinked collagen matrix (CM). Soft tissue healing was clinically evaluated on the basis of a specific healing index. Horizontal and vertical ridge dimensional changes were assessed clinically and radiographically at baseline and 6 months after implant placement. For histological and histomorphometric analysis, bone biopsies were harvested from the augmented sites during implant surgery 6 months after the socket preservation procedure. Results: Clinically, healing proceeded uneventfully in all the sockets. A trend towards reduced horizontal and vertical socket dimensions was observed from baseline to the final examination. The mean width and height of resorption were 1.21 mm (P=0.005) and 0.46 mm (P=0.004), respectively. Histologically, residual xenograft particles ($31.97%{\pm}3.52%$) were surrounded by either newly formed bone ($16.02%{\pm}7.06%$) or connective tissue ($50.67%{\pm}8.42%$) without fibrous encapsulation. The CM underwent a physiological substitution process in favour of well-vascularised collagen-rich connective tissue. Conclusions: Socket preservation using demineralised bovine bone mineral in combination with CM provided stable dimensional changes of the alveolar ridge associated with good reepithelialisation of the soft tissues during a 6-month healing period.

• The korean journal of orthodontics
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• v.48 no.5
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• pp.339-345
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• 2018

Objective: The purpose of this study was to clarify the effects of continuous force application for extrusive tipping movement and occlusal interference on periapical root resorption in the rat mandibular first molar. Methods: We constructed an appliance comprising a titanium screw implant with a cobalt-chromium post as the anchorage unit and a nickel-titanium closed coil spring (50 cN) as the active unit. Force was applied on the mandibular left first molar of rats for 8 (n = 10) and 15 days (n = 10; experimental groups), with the tooth in occlusion. Five rats were included as a non-treated control group to examine the body effect of the appliance. Active root resorption lacunae, identified using tartrate-resistant acid phosphatase, were evaluated in terms of the length, depth, and area. Results: The rat mandibular first molars were mesially tipped and extruded in the occlusal direction. This mesio-occlusal tipping movement and occlusion resulted in the formation of a compression zone and active root resorption lacunae in the distoapical third of the distal roots. However, there was no significant difference in the amount of root resorption between the two experimental groups. The control group did not exhibit any active root resorption lacunae. Conclusions: Periapical root resorption was induced by continuous extrusive tipping force and occlusal interference in rat mandibular molars. These data suggest that we orthodontists had better take care not to induce occlusal interference during our orthodontic treatment.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.117-122
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• 2018

In this study, HU(hounsfield unit) value of CT generated by dental prosthesis was measured according to the type of metal when PET-CT was performed, and the degree of distortion and standard deviation of SUV(standard uptake value) and to propose a method to reduce errors in image reading. PET-CT was performed using actual teeth, metal crown, gold crown, titanium, and zirconia dental prosthesis. Compared with general teeth, the SUV value increased with increasing HU value. The SUV value of metal crown, titanium, and zirconia was increased by 37% and the gold crown increased by 45.4%. In addition, image distortions were small in general teeth, metal crown, titanium, and zirconia, but hard curing of the gold crown occurred and image distortion occurred. Therefore, since the metal type of the dental prosthesis affects the SUV value, the NAC(non attenuation correction) PET image of the dental prosthesis can be helpful in the diagnosis of the patient using the gold material.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5773-5778
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• 2011

Results regarding the anti-oxidative, anti-allergic, anti-bacterial and anti-cancer effects of lotus leaf and dandelion have been reported through active research on the medical effects of medicine prepared from crude drugs. This paper aimed to examine the anti-bacterial effect of lotus leaf and dandelion extracts on S. mutans by evaluating the colony forming unit and growth curve. In accordance with the growth inhibition rate of S. mutans according to the addition of lotus leaf and dandelion extracts, the higher the extract concentration was, the higher the growth inhibition rate of S. mutans was. This paper therefore verifies that lotus leaf and dandelion extracts have an effect in inhibiting the growth of S. mutans.

• Genomics & Informatics
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• v.19 no.1
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• pp.5.1-5.11
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• 2021

Head and neck squamous cell carcinoma (HNSCC) is the most frequent type of head and neck cancer that usually arises from the mucosal surfaces of several organs including nasal cavity, paranasal sinuses, oral cavity, tongue, pharynx, and larynx. The Wnt signaling pathway is a crucial mechanism for cellular maintenance and development. It regulates cell cycle progression, apoptosis, proliferation, migration, and differentiation. Dysregulation of this pathway correlates with oncogenesis in various tissues including breast, colon, pancreatic as well as head and neck cancers. The present study aims to assess the gene alterations in the Wnt family of genes so as to derive an association with HNSCC. Computational approaches have been utilized for the identification of gene alterations in the Wnt family of genes. Several databases such as cBioportal, STRING, and UALCAN were used for the purpose. The frequency of alteration was high in case of Wnt family member 11 (5%). Gene amplification, deep deletions, missense and truncating mutations were observed in HNSCC patients. There was a marked difference in the gene expression profile of WNT11 between grades as well as normal samples. The survival probability measured using the Kaplan-Meier curve also presented with a significant difference among male and female subjects experiencing a low/medium level expression. The female patients showed less survival probability when compared to the male subjects. This provides the prognostic significance of the WNT11 gene in HNSCC. Taken together, the present study provides clues on the possible association of WNT11 gene alterations with HNSCC, which has to be further validated using experimental approaches.

• Journal of The Korean Dental Society of Anesthesiology
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• v.5 no.1 s.8
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• pp.22-24
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• 2005

General anesthesia is often required for mentally retarded children undergoing extensive dental treatment. We experienced a case of dental treatment under general anesthesia in a 14-year-old boy with mental retardation. He was treated on an outpatient basis. He was diagnosed of Noonan syndrome and received heart surgery when he was six years old. Induction using thiopental and vecuronium was uneventful and nasotracheal intubation were carried out. General anesthesia was maintained with sevoflurane for 2.5 hours. After monitoring the patient for 2 hours and confirming his recovery, he was discharged from the day care unit. In summary, we report this successful anesthetic management of a mentally retarded child during dental treatment in as an out-patient.

• Journal of Technologic Dentistry
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• v.36 no.4
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• pp.257-266
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• 2014

Purpose: This report intend to provide basic materials of Musculoskeletal diseases prevention program development and preventive measures establishing by surveying Musculoskeletal symptoms. Musculoskeletal disease and Musculoskeletal disease prevention act about dental technician in Daegu. Methods: From October. 2012 to November. 2012 by conducting self - survey using questionnaire and use unit490 final analysis data. Results: In dental Technicians, as the musculoskeletal symptoms back or waist pain rate appear such as 28.2% and as the musculoskeletal disorders, the shoulder region pain complaint rate appear highly such as 87.4%. Musculoskeletal disease prevention act was highly appeared man more than women, the married than the unmarried, over 10 years dental experience, fewer working hours per day, the average monthly income is greater regular medical check-up dental technician than technician who do not. As working environment, In case working in laboratory whch dust is well ventilated and with a barrier, Musculoskeletal disease prevention act rate was highly appeared more than another technician who do not. Conclusion: We must prepare an effective preventive measures. To development Musculoskeletal disease prevention program suitable for dental technic working and make obliged to practice.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.1
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• pp.16-22
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• 2014

Purpose: The purpose of this study was to assess the marginal and mesial fitness of zirconia single copings and 3-unit fixed partial dentures (FPDs) manufactured with an identical model. Materials and Methods: An epoxy model in which the maxillary right 2nd premolar is lost and maxillary 1st premolar and 2nd molar are formed as abutments was manufactured and scanned by using a laser scanner. A ten units of zirconia single copings were manufactured for maxillary 1st premolar and 2nd molar, respectively and the same number of 3-unit FPDs were manufactured. For the measurements of fitness, the manufactured silicone replicas were divided into four parts and the fitness were measured by digital microscope at measurement points (P1, P2, P3, P4 and P5) of each plane. The measured gaps were classified into three categories: marginal gap (MG, P1), axial gap (AG, average of P2 and P3), occlusal gap (OG, average of P4 and P5). Results: The ranges of MG, AG and OG for single copings were 18.47 - 40.54 ${\mu}m$, 39.73 - 73.61 ${\mu}m$ and 116.90 - 134.69 ${\mu}m$, respectively. The ranges of MG, AG and OG for 3-unit FPDs were 45.95 - 87.44 ${\mu}m$, 23.78 - 57.00 ${\mu}m$ and 99.89 - 131.06 ${\mu}m$, respectively. Conclusion: The result of the study shows that the MGs for 3-unit FPDs were higher than those of single copings, though they are within the range of clinical acceptance, indicating that the use of more homogeneous zirconia block and modification of sintering processes are needed to ensure the prevention of increase of gap in 3-unit FPDs.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.232-237
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• 2015

The water supplied from dental unit water systems (DUWS) in dentistry may be heavily contaminated with bacteria and thus may be a potential source of infection for both practice staff and patients. The aim of this study was to evaluate the level of heterotrophic bacteria and to confirm the presence of opportunistic pathogens from DUWS in student clinical simulation laboratory of college of dentistry. Water samples were collected from 36 ultrasonic scalers in student clinical simulation laboratory. The levels of heterotrophic bacteria in water samples were quantified by counting colony forming units (CFUs) on R2A agar media. In addition, opportunistic pathogens were detected by using the polymerase chain reaction (PCR) method. The mean CFUs were 16,095 CFU/ml for water samples and all of water samples exceeded current American Dental Association recommendations of 200 CFU/ml. Pseudomonas species and non-tuberculous Mycobacterium species were detected in the one sample and two samples, respectively, among the 36 water samples by the PCR with specific primers for these bacteria. Our study indicated that DUWS in student clinical simulation laboratory can cause potential infection in students and participants. This study suggested the dental unit water line management and wearing personal protective equipment in student clinical simulation laboratory will be needed to reduce bacterial contamination.