• Tribology and Lubricants
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• v.29 no.4
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• pp.235-241
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• 2013

The tribological characteristics of dental metal alloys and zirconia were studied by carrying out a friction and wear performance test. In this study, a pin-on-disk-type tester was used and dead weight was employed as the normal load applied to the test specimen. The friction coefficient of dental metal alloys was investigated in terms of their weight and sliding velocity. Microscopic observations were carried out on worn surfaces of specimens. The results indicated that among all metal alloys, Super-A had the highest friction coefficient. Super-A had the lowest amount of wear among all metal alloys, and the amount of wear increased in the following order: Crown & Bridge, Porcelain, and Partial. Crown & Bridge had the best friction coefficient, but the hardness of Crown & Bridge was lower than that of Porcelain and Partial. Experimental measurement results indicated that the disk weight before and after the experiment was the same.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.2
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• pp.113-123
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• 2001

The success of complete denture prosthesis is to satisfy three basic requirements for the edentulous patient : maximum comfort, efficiency, and esthetic appearance. This can be achieved only if the dentures are both stable and retentive. When the residual alveolar ridge has resorbed significantly, stability and retention are more dependent on the correct position of the teeth and external surfaces of the denture. The stability and retention of the denture can be improved by locating the denture in the neutral zone and reproducing exact mandibular border movement for balanced occlusion. The neutral zone philosophy is based upon the concept that there exists a specific area where the musculature function will not unseat the denture in the mouth. In here, forces generated by the tongue are neutralized by the forces generated by the lips and cheeks. One of the simplest methods for recording border movements in three dimensions is to make stereographic record of condylar movement. Stereographs are made in the mouth during mandibular movement with intraoral clutches and central bearing point, and used in dictating the condylar movement on the articulator later by generating the condylar paths in doughy acrylic resin. Its procedure is simpler and more convenient than that of Pantograph. In this clinical report, we introduce the concept of neutral zone and stereograph in complete denture fabrication.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.499-505
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• 1998

Idiopathic gingival hyperplasia is a rare condition of undetermined etiology. The enlargement is usually associated with the emergence of the teeth into the oral cavity and may regress after extraction. The enlarged gingiva may be primarily attributed to hyperplasia of the subepithelial layer that is relatively avascular and consists of densely arranged collagen bundles and numerous fibroblasts. The recommended time for treatment is after completion of eruption of permanent teeth. But the most important thing is the patient's psychological and esthetic needs. Lately, Schluger has proposed modified gingivectomy procedure with horizontal, internal beveled incision for thinning of the flap resulting in less pain and bleeding after treatment, minimal opportunity of infection. The purpose of this report is to document a case of 8-year-old girl who had registered in Dept. of Pediatric Dentistry of Seoul National University dental hospital for treatment of her gingival hyperplasia and delayed tooth eruption

• The Journal of the Korean dental association
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• v.44 no.11 s.450
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• pp.739-747
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• 2006

Objectives. The standardization of connection between fixture and abutment has not been defined. The success of dental implants was not always depends on connection. However, the connection mechanism is one of the most important things for dental implant treatment success. Most implant systems are very comparable in their design and engineering. They share many common characteristics and have similar strengths and weaknesses. Their significant weaknesses are connection, microgap and the resulting micromovement allowing bacterial contamination and bone loss. In the present study, we investigated the clinical performance of Ankylos implant (conical connection implant) Patients and Methods. The clinical performance of conical connection implant was studied under well-controlled clinical conditions. A total of 133 conical connection implants were placed in 50 patients from April 2005 to March 2006. The mean follow-up loading period of implants which was considered successful was 220$\pm$29 days. We recorded the age, sex, installation site, reason of edentulous region, bone density of installation site, diameter and length of dental implants and periods from installation to uncovering surgery using patients medical chart. Results Four Ankylos implants were lost during pre-loading period. 129 implants provided excellent clinical performance during 220$\pm$29 days on an average. The short-term success rate of this conical connection implant system was 96.99%.

• Korean Institute of Interior Design Journal
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• v.19 no.1
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• pp.217-225
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• 2010

As life quality have grown today, People have been greatly interested in health. Moreover, new knowledge and concepts are being applied in the medical facility field and that makes the field expand constantly. Hereby, this research is a study on design elements of dental clinics and the research goals are to understand interior design of current dental clinics by investigation and analysis on furniture, closing materials, colors and so on, and to investigate esthetic and functional environments for dental clinics through analyzing upcoming trends of inner spaces of dental clinics. The investigation was conducted by visits to four clinics per each research area, where are in Busan area and opened after year 2000 and are located in Seoul and Busan. Though the spaces of dental clinics vary according to the characteristics of each clinic, it generally has a consultation room, a waiting room and an X-ray room. The closing materials that make patients feel at ease are used in the waiting room, and ones that make patients feel tidy and fresh are used in consultation spaces, spare spaces, and management spaces. In Seoul area, antique and harmonic colors are used, and modernistic colors are used in Busan area. Reception desks, chair units, sofas and sink storage shelfs are the common furniture in the clinic. We have learned what are mentioned above by research and investigation on the component characteristics of dental clinic spaces. Based on these, more systematical and in-depth research should be continued.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.4
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• pp.308-315
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• 2011

Purpose: The purpose of this study was to colorimetrically evaluate the masking effect of different opacity of ingots on the final shade of IPS Empress Esthetic$^{(R)}$ laminate veneer restorations using the CIE $L^*a^*b^*$ system. Materials and methods: Six porcelain disks of IPS Empress Esthetic$^{(R)}$ system (translucency: E 01, E 03, E 0C-1, E TC-1, E TC-2, E TC-3) were fabricated with 7 mm in diameter and 0.6 mm in thickness. Six extracted human incisors (shade: A1, A3, A4, B2, B3, C3) were used as the abutment specimens. The incisors were prepared using a diamond wheel and made with a flat labial surface on the middle 1/3. For each combination of different shades of abutments and copings, the change in color was measured with a colorimeter. CIE $L^*a^*b^*$ coordinates were recorded for each specimen. Color differences (${\Delta}E$) were calculated. Descriptive statistical analysis was done. Results: ${\Delta}E$ values were significantly affected by coping translucency and abutment shade (P<.05). The color differences (${\Delta}E$) of laminate veneers among abutments with A3, B3, C3, and A4 shade were mostly below 2.7 which was within the clinically acceptable range, while color differences between A4 and B2, A3 and B2, and A1 and A4 showed more than 2.7. Conclusion: The final color of IPS Empress Esthetic$^{(R)}$ laminate veneers were significantly influenced by translucency of the coping and shade of abutment teeth. The large value difference of abutment teeth limited the masking ability by laminate veneers.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.283-291
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• 2008

The malar mound defines the contour of the lateral face between the inferior orbital rim and the mandible, and hypoplasia or asymmetry of this region is readily noticeable. A flat, hypoplastic malar eminence can make the face blunt and wearisome, which contributes to a premature aged appearance. Patients with congenital or traumatic flattening of the malar eminence can obtain esthetic improvement with implants. Indications for placement of malar implants to improve the appearance of subtle flattening or to enhance the esthetic harmony of a patient's face have been suggested in several studies. Many augmentation materials, such as silicone, proplast, polyamide, and porous polyethylene implants have been used. Many methods of localization have been described, the key to proper placement of the implants lies in a through understanding of the esthetics of the malar mound. From August 2001 to June 2007, 12 patients with malar depression who visited the Department of Oral and Maxillofacial Surgery, Chonnam National University Hospital were treated by augmentation malarplasty with Porous polyethylene. The location and amount of augmentation are determined by preoperative interview, physical examinations, facial models and radiographic findings. 12 patients were satisfied with the results of augmentation malarplasty and severe complications were not occurred.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.28 no.2
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• pp.116-126
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• 2019

Objectives: Currently, oral health of the disabled is taken care of by the social workers, not by dental hygienists, who are the oral health professional in this area. Therefore, we aim to enhance the equity of oral health for the disabled by providing the correct oral health care method to social workers residing in the welfare facility for the disabled. Methods: Four dental hygienists and four social workers were given the class I intellectual disabilities living in 'o' welfare facilities for disabled people in Songpa-gu, Seoul from April 13, 2019 to April 20, 2019. Patient Hygiene Performance(PHP) Index were measured and compared. In advance, the social workers were taught brushing (Rolling method), and the method of brushing and measuring tools were integrated. Results: Twice a total of dental hygienists and social workers practiced toothbrushing(Rolling method) for the class I intellectual disabilities who is a person to be brushed. When comparing the Patient Hygiene Performance(PHP) Index after the second round, the result shows that both the first and second dental hygienists' Patient Hygiene Performance(PHP) Index is lower. Conclusions: Comparing oral health knowledge level and Patient Hygiene Performance(PHP) index of dental hygienist and social workers, the result shows that dental hygienist has higher oral health care ability. Therefore, the dental hygienist should be placed in welfare facility for the disabled as an expert in oral health management to create an environment in which the disabled and social workers can be trained. In addition, the curriculum of the college that nurtures the dental hygienists should have a course to understand the characteristics of the disabled person in order to enhance the professionalism of dental hygienists.

• The Journal of the Korean dental association
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• v.15 no.3
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• pp.205-208
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• 1977

The etiology of masseteric hypertrophy is obscure. When the hypertrophy occurs unilaterally it's appearance is more striking because of the resultant facial asymmetry. Two soldiers were admitted with the complaint of a lump on their jaws. The authors obtained good results on the esthetic & functional aspect in two cases of unilateral masseteric hypertrophy with the Adam's method. The etiology was thought to be the combination of unilateral masticatory and jaw clenching habits when emotionally disturbed or under nervous tension in army services.

• The Journal of the Korean dental association
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• v.54 no.8
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• pp.651-657
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• 2016

Currently with the continuous development of ceramic and cementation materials, CAD-CAM(Computer-aided design/Computer-aided manufacture) restorations are becoming increasingly popular in esthetic dentistry. Preparation design is influenced by the selected restorative material, the fabrication method, and the ability to bond the restoration. For long-lasting CAD/CAM inlay/onlay restoration, clinicians should understand the basic knowledge of CAD/CAM restoration's cavity design to obtain the fracture resistance and proper fitting margin. This article gives an overview of preparation guidelines for CAD/CAM inlay/onlay restorations.