• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.239-245
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• 2014

Complete denture prosthodontics includes replacement of natural teeth and associated maxillary and mandibular structures for full edentulous patients. The final objectives of prosthodontic treatment include esthetic and functional rehabilitation. Because the esthetic demand of senior patients has increased esthetic requirement should not be overlooked in denture treatment. In complete denture treatment, attempts have been made to reproduce tooth wear, arrangement, recession of cervical gingiva, staining, improved gingival shade and so on. This 61 year old female patient came to the Department of Prosthodontics with the chief complaint that dentures made 5 years ago in a local clinic were broken and did not fit well. The patient put more emphasis on fabrication of natural and esthetic dentures than recovery of masticatory function. Remake of maxillary complete denture and mandibular implant retained overdenture was planned. In order to create esthetic and natural contour, Aesthetic Color Set Easy system$^{(R)}$ (Candulor dental GmbH, Wangen, Germany) was used to make complete dentures reproducing various gingival shades. Patient's esthetic satisfaction was high. When complete denture prosthodontics treatment involves appropriate expression of individual characteristics in addition to proper selection of esthetic materials, treatment will give satisfaction to both dentist and patient.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.40-61
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• 2009

The Cretaceous Gyeongsang Supergroup, composed of clastic sediments mostly deposited in the lacustrine and fluvial environment, is widely distributed in the southern part of the Korean Peninsula. Diverse fossils of plants, molluscs, insects, footprints of dinosaurs, pterosaurs and birds, and eggs, bones, and teeth of dinosaurs have been found from the Gyeongsang Supergroup. New types of dinosaur, pterosaur, and bird tracks recently discovered from the Gyeongsang Supergroup attract great attention from the world. Several tracksites of dinosaurs and birds were designated as Natural Monument and nationally conserved, and many efforts have given to them for nomination of UNESCO World Heritage. Bird tracks from the Gyeonsang Supergroup are Koreanaornis hamanensis, Jindongornipes kimi, Goseongornipes markjonesi, Ignotornis yangi, Uhangrichnus chuni, and Hwangsanipes choughi, which correspond approximately one third of Mesozoic bird tracks recorded from the world. The Gyeongsang Basin of the Korean Peninsula yields world most diverse bird tracks which may be called a paradise of Mesozoic birds and they are important natural heritage providing significant information about evolution and paleogeographic distribution of birds.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.261-265
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• 2014

The ${\gamma}$-ray concentration and gross-${\beta}$ activity by age group were measured in the teeth of males and females of the domestic residents. They were divided into 7 age groups from 10s to the age of 70s. The gross-${\beta}$ activity concentration was measured by using the Tennelec XLB measuring instrument filled with P10 gas (argon 90%, methane 10%). The ${\gamma}$-ray was measured through the ${\gamma}$-ray spectroscopic analytical method by using the high purity germanium (HPGe) radiation detector. The range of gross-${\beta}$ activity concentration was measured 0.089 to 0.32 Bq/kg in females and 0.13 to 0.26 Bq/kg in males. From the ${\gamma}$-ray spectroscopic analysis of the teeth, the natural radioactive isotopes of $^{40}K$, $^{208}Tl$, $^{228}Ac$ and $^{234}Th$ were detected and their measured ${\gamma}$-ray activity concentrations were found to be 20.7, 21.9, 3.88 and 5.24 Bq/kg, respectively.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.3
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• pp.287-295
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• 2002

Statement of Problem. Endodontically treated teeth frequently required posts and cores to provide retention and resistance form for crowns. In spite of excellent mechanical properties of metal post and core, its metallic color can be detected through all ceramic restorations occasionally. To solve esthetic problems of metal post and core zirconia post system has been introduced recently. Purpose. The purpose of this study was to examine the fracture strength and mode of resin root analogs restored with zirconia, gold and titanium posts with resin, ceramic and metal cores after cementation with metal crowns. Materials and methods. To avoid the morphological variations of natural teeth, 40 root analogs were fabricated with composite resin. Forty resin root analogs were randomly assigned to four groups according to post and core materials: Group A: cast gold post and core and complete cast crowns, as control. Group B: titanium posts (Parapost, Coltent/Whaledent Inc., NJ, USA) and composite resin cores. Group C: zirconia posts (Cosmopost, Ivoclar AG, Schaan/Liechtenstein) and composite resin cores Group D: zirconia posts and heat-pressed ceramic cores (IPS Empress Cosmo Ingots, Ivoclar AG) After thermocycling ($5^{\circ}C{\sim}55^{\circ}C$, 30 sec.), cyclic loading was applied at 3mm below the incisal edge on the palatal surfaces at an angle of 135 degree to the long axis (2Hz, 50N, 50000cycles). Fracture strength was measured by universal testing machine (Instron, High Wycombe, UK) and fracture pattern of restored resin root analogs was also evaluated. Results and conclusion. Within the limitations of this study following results were drawn. 1. Resin root analogs restored with zirconia posts and composite resins demonstrated lowest fracture strength among tested groups. 2. There was no significant difference in the fracture strength between zirconia posts and heat pressed glass ceramic cores and cast gold posts and cores 3. The fracture strength of resin root analogs restored with titanium posts and composite resin cores was lower than that of gold posts and cores. 4. The deep oblique fracture lines were dominantly observed in root analogs restored with cast gold post and core and zirconia post and heat-pressed ceramic core groups.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.13-17
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• 2005

Children and teenagers have a higher frequency of proximal surface caries in the posterior teeth than adults. For proximal restoration, class II amalgam or stainless steel crown has been widely used in the past, however composite resin restoration is getting ore popular due to it's superior cosmetic appearance. When applying composite resin on proximal area, various types of matrix bands can be utilized according to the operator's reference or skill. Such bands have several clinical effects including suitability for proximal margin, reduction of micro-leakage, moisture-control against saliva and ease finishing and polishing. In this case report, orthodontic bands were utilized instead of matrix bands as a remedy for proximal restorations in both primary and permanent teeth and their clinical advantages are as follows. 1. Orthodontic bands showed superior marginal adaptation compared to conventional matrix bands and moisture-control against saliva was excellent. 2. While applying composite resin, deformation of restoration material was estimated to be insignificant due to he rigidity of the orthodontic bands. 3. Natural tooth contour of the orthodontic bands facilitates to reproduce proximal tooth contour of the restoration. 4. In general, pediatric dentists are accustomed to applying orthodontic bands and this may allow pediatric dentists to make proximal composite restorations more efficiently than other dental specialists.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.1-10
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• 1998

The early history of Korean mandarin fish, Siniperca scherzeri was studied to obtain some information required in aquaculture and reinforcement of natural population. During the period from June 1996 to July 1997, the mature adults of Siniperca scherzeri were collected from the middle Soyang Lake at Puksan - myon, Chunchon - shi, Kangwon - do, Korea. The eggs from females were obtained by injecting HCG or/and GnRH - a and fertilized by dry method in the laboratory. The fertilized eggs, measuring 1.70~2.10 mm in diameter and expanded to 2.20~2.66mm after absorption of water, were globosity, light orange yellow, separative, submergence and had one large oil globules of 0.5~0.7 mm. The blastodisc was formed in 1 hour and cleavage started in 1 hour 30 min. after fertilization, and the intervals of each stage of cleavage was about 50 min. at the water temperature of $21{\sim}24^{\circ}C$. Hatching occurred 131 hours 30 min. after fertilization and newly hatched larvae were 5.86~6.85 mm in total length(TL) and numerous stellate melanophores were distributed on the yolk and abdomen of caudal peduncle. The yolk was almost absorbed and the teeth development. 3 days after hatching, at 6.98~7.60 mm TL. The head spines and the teeth were largely developed and all fins were completely formed and became postlarva stage 15 days after hatching, at 10.10~12.90 mm TL. The body shape and the color pattern were similar to adult, 25 days after hatching, at 15.3~23.8 mm TL. In 5 months after hatching were reached at 154.10~175.02 mm TL and 49.32~82.67 g in body weight.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.2
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• pp.203-244
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• 1998

The human mandible is always under the condition of loading by the various forces extorted by the attached muscles. The loading is an important condition of the stomatognathic system. This condition is composed of the direction and amount of forces of the masticatory muscles, which are controlled by the neuromuscular system, and always influenced by the movement of both opening and closing. Mandible is a strong foundation for the teeth or various prostheses, nevetheless it is a elastic body which accompanies deformation by the external forces on it. The elastic properties of the mandible is influenced by the various procedures such as conventional restorative treatments, osseointegrated implant treatments, reconstructive surgical procedures and so forth. Among the treatments the osseointegrated implant has no periodontal ligaments, which exist around the natural teeth to allow physiologic mobility in the alveolar socket. And so around the osseointegrated implant, there is almost no damping effect during the transmission of occlusal stress and displacements. If the osseointegrated implants are connected by the superstructure for the stabilization and effective distribution of occlusal stresses, the elastic properties of mandible is restricted according to the extent of 'splinting' by the superstructure and implants. To investigate the change of elastic behaviour of the mandible which has osseointegrated implant prosthesis of various numbers of implant installment and span of superstructre, a three dimensional finite element model was developed and analyzed with conditions mentioned above. The conclusions are as follows : 1. The displacements are primarily developed at the area of muscle attachment and distributed all around the mandible according to the various properties of bone. 2. The segmentation in the superstructure has few influence on the distribution of stress and displacement. 3. In the load case of ICP, the concentration of tensional stress was observed at the anterior portion of the ramus($9.22E+6N/m^2$) and at the lingual portion of the symphysis menti($8.36E+6N/m^2$). 4. In the load case of INC, the concentration of tensional stress was observed at the anterior portion of the ramus($9.90E+6N/m^2$) and the concentration of tensional stress was observed at the lingual portion of the symphysis menti($2.38E+6N/m^2$)). 5. In the load case of UTCP, the relatively high concentration of tensional stress($3.66E+7N/m^2$) was observed at the internal surface of the condylar neck.

• Journal of dental hygiene science
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• v.7 no.3
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• pp.167-177
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• 2007

The purpose of this study was to obtain basic data for dental implants prosthetic maintenance care after analysis perceptions of dental implants. A question was used to questionnaire by 210 dental patients at five dental clinics in the Jinju-city. In conclusion, 1. The knowledge level about implant is 'Never'(35.7%). 2. A feeling of unrest during implant surgery is 'pain'(37.6%). 3. The expectation level about dental implants function is 70% of natural teeth(36.2%). 4. The main function of implant teeth is 'mastication'(70.5%). 5. The implant hygiene supplies for the dental implants maintenance is 'proximal brush'(60%). 6. The important maintenance attitude for the dental implants is 'regularly dental examination'(42.9%). 7. The interval regularly for implant examination is 'six monthly'(44.8%).

• Journal of dental hygiene science
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• v.12 no.5
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• pp.535-544
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• 2012

This purpose of this study was to analysis the relation of awareness and practices of oral health promotion. The subjects in this study were 133 workers who worked in Seoul, Gyeonggi province, and were at the age of 20 and up. The survey was conducted from January 16 to March 31, 2012. The collected data is statistically analyzed by SPSS. For the level oral health awareness of industrial workers, the awareness of prevention of tooth decay and periodontal disease was high, but that of necessity of oral hygiene supplies other than tooth brushing was low. For the level of oral health care practice, they showed the highest awareness for the importance of cleaning a tongue when brushing teeth, and the lowest for the importance of dental care. For oral health awareness according to the general properties, workers with average income of 2~3 million one showed higher oral health awareness than others. For oral health care practice, those who brush their teeth more than 3 times a day and who have visited the dentist during the last year had higher oral health care practice than others. For oral health awareness according to the level of interest in oral health and the status of oral health of the industrial workers, those who have higher interest in oral health turned out to have higher oral health awareness. The relation between oral health awareness and oral health care practice of the industrial workers showed a positive correlation, which indicates that the higher oral health awareness is, the higher oral health care practice is.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.26 no.1
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• pp.4-16
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• 2017

In dental esthetics, soft tissue plays an important part, probably very large portion of it. A clear understanding of the periodontal tissues and its management around teeth and implants help us to develop concepts for a modern dental treatment that addresses the needs of demanding patients in regard of esthetics and durability. When we talk about esthetic, we can say that one of the most important element is a harmonization with gingiva (soft tissue) called 'Pink Esthetic' As for the pink esthetics, gingival line(contour) takes most of the influence on esthetic result; it consists of labial gingival level, interproximal papilla height, and a line that connects them. In the gingival recession, labial gingival level and gingival contour move to the apical portion, and the root area is exposed. It leads to the unesthetic result. Root coverage technique is classically used to treat gingival recession (marginal tissue recession) of natural teeth. It is an essential technique on periodontal plastic surgery part. It is also a very useful technique to recover soft tissue problems in implant dentistry. So, root coverage technique must be mastered for a good implant esthetic result. The general overview of root coverage procedures will be discussed with step by step explanation to get more esthetic result.