• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.511-522
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• 2011

Objectives : The purpose of this study was to provide some information on the development of oral health care programs geared toward diabetics and ways of promoting their oral health. Methods : The subjects in this study were 586 diabetics who were selected from the 2009 third-year raw data of the 4th(2007~2009) National Health & Nutrition Survey. The data were analyzed with the statistical package SPSS 12.0 to grasp the influence of their sociodemographic characteristics and oral health behaviors on the presence or absence of periodontal diseases and missing tooth. Results : 1. Periodontal diseases were twofold more prevalent among the men than the women(p<0.01). By age, those who were in their 60s had 1.11-fold more periodontal diseases than those who were in their 70s and up(p<0.05). 2. The men and women were similar to each other in the number of missing tooth. By age, the number of missing tooth got smaller in proportion to decrease in age. By income, the number of missing tooth was 1.48-fold larger among the patients who earned an income of one million won or less than those who earned an income of two million won or more(p<0.01). Conclusions : The above-mentioned findings suggest that prospective cohort studies should be implemented to present prediction models of periodontal diseases and diabetes instead of merely sticking to cross-sectional studies. And oral health programs should be developed based on the findings of cohort studies to encourage diabetics to care about their oral health, and in which way they should be helped to promote their oral health should carefully be considered.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.3
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• pp.123-133
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• 2024

Dentoalveolar (DA) trauma, which can involve tooth, alveolar bone, and surrounding soft tissues, is a significant dentofacial emergency. In emergency settings, physicians might lack comprehensive knowledge of timely procedures, causing delays for specialist referral. This systematic review assesses the literature on isolated DA fractures, emphasizing intervention timing and splinting techniques and duration in both children and adults. This systematic review adhered to PRISMA guidelines and involved a thorough search across PubMed, Google Scholar, Semantic Scholar, and the Cochrane Library from January 1980 to December 2022. Inclusion and exclusion criteria guided study selection, with data extraction and analysis centered on demographics, etiology, injury site, diagnostics, treatment timelines, and outcomes in pediatric (2-12 years) and adult (>12 years) populations. This review analyzed 26 studies, categorized by age into pediatrics (2-12 years) and adults (>12 years). Falls were a common etiology, primarily affecting the anterior maxilla. Immediate management involved replantation, repositioning, and splinting within 24 hours (pediatric) or 48 hours (adult). Composite resin-bonded splints were common. Endodontic treatment was done within a timeframe of 3 days to 12 weeks for children and 2-12 weeks for adults. Tailored management based on patient age, tooth development stage, time elapsed, and resource availability is essential.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1391-1394
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• 2007

In order for Hypoid gear development. Gears are required to sustain heavy loads or on applications where the gear box is made or a material with a different coefficient of thermal expansion form that or the gears and shafts, it is desirable to make a deflection and contact check under load. The deflection test is performed in the actual gear mounting using completely processed gear. This test should cover the full operating range of gear loads from no load to peak load. Under peak load the contact pattern should extend to the tooth boundaries without showing a concentration of the contact pattern at any point on the tooth surface.

• Transactions on Electrical and Electronic Materials
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• v.14 no.5
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• pp.268-272
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• 2013

The aim of this study was to develop an ultrasonic tooth-whitening apparatus using piezoelectric transducers, which enhance bleaching efficiency by applying ultrasound, while performing a teeth whitening procedure. For this purpose, an ultrasonic transducer was designed and manufactured, and the effects of reduction in the whitening material's concentration and in the whitening treatment time through using the ultrasound cavitation phenomenon were confirmed. Also, the validity of this study was investigated by comparing the whitening performance with a commercialized optical whitener, through color comparison. The results revealed that the ultrasound whitener produced color values that were enhanced by as much as double that of the conventional LED light whitening method. Even when the operational time was reduced by half, the ultrasound method showed superior performance by over 54% compared to the conventional light whitener, revealing that the ultrasound method showed a remarkable treatment reduction effect.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.3
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• pp.710-717
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• 1997

Autotransplantation is the transplantation of embeded, impacted, or unerupted tooth, into extraction socket or surgically prepared socket in the same individual. Clinically, successful autotransplantation must show radiolucent space(periodontal ligament space) between transplanted tooth and supporting bone, lamina dura, no root resorption, no ankylosis, no inflammatory change, and physiologic tooth mobility. It is important that procedure is atraumatic, and the instruments should not contact the root surface during procedure. We performed autotransplantation of impacted mandibular canine that transversely located beneath the apices of the mandibular incisors with uncompletely developed apex. In radiographs and clinical evaluation, this transplant showed successful clinical finding except irregularity of mesial root surface after 14 months. It is conclued that transplantation of canine with $\frac{1}{2}{\sim}\frac{3}{4}$ root development provides a good chance of pulp survival, limited risk of root resorption and ensures sufficient final length, and is thus recommended.

• Journal of Power System Engineering
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• v.12 no.6
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• pp.78-82
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• 2008

Plastic gears are more and more widely used in many industrial machine elements. Plastic gear has higher properties such as light weight, wear resistance, and vibration absorbing ability than metallic gears. But, in case of using an inaccurate plastic gear, its tooth breakage happen and fatigue life is shortened due to increase of applying load and temperature rising on the tooth flank. Inaccuracy of plastic gears such as pitch circle roundness and tooth profile generates vibration and noise. In this study, an internal plastic gears which is molded by a new injection mold structure are developed. The new mold structure is called the HR3P(hot runner type 3plate mold) that has an improved runner system in order to have good filling balance. As a result from this study, an internal gear with very accurate roundness was developed by using design of experiment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.2
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• pp.63-69
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• 2017

Nuclear factor I-C (NFI-C) plays a pivotal role in various cellular processes such as odontoblast and osteoblast differentiation. Nfic-deficient mice showed abnormal tooth and bone formation. The transplantation of Nfic-expressing mouse bone marrow stromal cells rescued the impaired bone formation in $Nfic^{-/-}$ mice. Studies suggest that NFI-C regulate osteogenesis and dentinogenesis in concert with several factors including transforming growth factor-${\beta}1$, $Kr{\ddot{u}}ppel$-like factor 4, and ${\beta}$-catenin. This review will focus on the function of NFI-C during tooth and bone formation and on the relevant pathways that involve NFI-C.

• Journal of the Korean Ceramic Society
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• v.20 no.1
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• pp.55-62
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• 1983

the preliminary work on the prepartion of fine hydroxyapatite powder and the synthesis of dense hydroxyapatite ceramic from the powder were investigated for the development of artificial bone and tooth materials for implants. The effects of the process variables such as compositions of the raw materials the initial pH of the solutions and sintering temperature on the physical properties were investigated in order to determine the optimum conditions for the fabrication of tooth implant material. As the initial pH of the solutions was increased in the range of 10-11.6 the initial particle size of precipitates was decreased thus the sinterability of precipitates was improved. It was found that the composition of calcium rich of 1.75 in Ca/P mole ratio exhibited better sinterability and mechanical strength of the apatite ceramics for example the highest value of Vicker's hardness obtained from the compositions of 1.75 in Ca/P mole ratio was 764±30 Kg/mm2 compared to the maximum value of 600 kg/mm2 obtained from the compositions of 1.67 in Ca/P mole ratio.

• The Journal of the Korean dental association
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• v.55 no.5
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• pp.352-357
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• 2017

Teeth are made up of three hard tissues, enamel, dentin, and cementum. The dental pulp is the only non-mineralized connective tooth tissue that is surrounded by dentin. The dentin-pulp complex is able to respond to injury by producing hard tissue deposition. However, dentin is considered one of the most difficult tissues to regenerate because of its unique anatomic and physiologic nature. Recently, advances in understanding the applicability of bio-active dentin regenerating proteins are emerging with the development of biological-based therapies using bio-active materials. Dentin defects were regenerated by the deposition of tubular physiologic dentin after application of the bio-active protein in a beagle dog model. Therefore, the bio-active protein may be able to serve as a novel dentin regenerating material and improve symptoms of dentin hypersensitivity.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.586-586
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• 2003

In the infected immature tooth with periapical involvement, the pulp is considered to hardly exist in the canal and periapical area. Such a tooth receives apexification procedure, because revascularization of the pulp chamber is in principle not expected. Apexification is beneficial to induce further development of an apex to close the foramina, but does not promote the thickness of the entire canal wall dentin. It may be possible for the pulp to be only partially necrotic and infected when an extremely large communication from the pulp space to the periapical tissues exists with a very young tooth. If this were the case, vital pulp in the apical part of the canal could proliferate new pulp into the coronal pulp space by the successful removal and disinfection of the necrotic infected coronal pulp.(omitted)