• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.79-87
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• 2012

Currently, The method to produce a brewing body for dentistry supplementation water produces a brewing body by fabrication, burying and it is heat wish in city gas and oxygen. It uses an original judgment found airplane the brewing body uses a spring of the back wait that melting temperature dissolved various alloys in by a blow pipe, and to generate centrifugal force and produces it. In addition, because it uses preheating to dissolve an alloy in general, it is hard to regulate the appropriate melting temperature of the alloy and brewing time and generates a brewing defect hereby same as gas industry and pinhole and shows the defect of the supplementation thing due to the super-heating. In this paper, We developed the high induction heating system which it could set brewing time,temperature and had durability and security,by the kind of the alloy to produce a high quality prosthetic thing brewing body.

• Journal of Technologic Dentistry
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• v.32 no.4
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• pp.351-356
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• 2010

Purpose: The purpose of this study was to evaluate the fracture strength between the core and veneering ceramic according to 2 core materials, In-Ceram Alumina and In-Ceram Zirconia, fabricated by electro ceramic layering technique. 2 different fixed partial denture cores of three units were veneered by veneering ceramic(Ceranion, Noritake) (n=10). Methods: The fracture strengths between the core and veneering ceramic were measured through the 3 point bending test. The interfaces between the core and veneering ceramic were observed with the X-ray dot mapping of EPMA. Results: The result of fracture strength was observed that IZP group, In-Ceram Zirconia core, had higher fracture strength. IPA group, In-Ceram Alumina core, had fracture strength of 359.9(${\pm}$86.2) N. IZP group, In-Ceram Zirconia core, had fracture strength of 823.2(${\pm}$243.0) N. X-ray dot mapping observation showed that a major element in the core and veneering ceramic of IPA group was alumina and silica, respectively. No binder was observed in interfaces between the core and veneering ceramic, and no ion diffusion or transition was observed between the core and veneering ceramic. However, apparent ion diffusion or transition was observed between the core and veneering ceramic of IZP group.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.1
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• pp.93-108
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• 2016

One of the fields to which the 3D printing technology can be applied is the field of medicine. Recently, the application of 3D printing technology to the bio-medical field has been gradually increasing with the commercializing of the bio-compatible or bio-degradable materials. The technology is currently contributing to the biomedical field by reducing times required for operations or minimizing adverse effects through preoperative identification of post-surgical consequences or model surgery with artificial bones and organs. This technology also enables the production of customized biomedical auxiliary products like hearing aids or artificial legs etc. For the field of dentistry, the 3D printing technology is also expected to elevate the level of dental treatment by making the customized orthodontic models, crown, bridge, inlay, and surgical guides for implant and surgery. However, issues remaining unidentified or incomplete in printing materials, modeling technology, software technology associated with CAD, verification of bio-stability and bio-effectiveness of materials or in compatibility and standardization of the technology are yet to be solved or be clarified for the full-scale application of the 3D printing technology, thus, it seems such issues should be resolved through further studies.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.123-131
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• 1982

The purpose of this study was to observe the responses of the remaining pulp tissue after pulpotomy upon the several kinds of $Ca(OH)_2$ products and the responses of periapical tissue upon some root canal filling materials after extirpation. For pulpotomy, the class V cavities were prepared on the premolars, molars and upper canines, and the pulp was amputated. Each drug was placed over the amputated tissue and cavity was sealed with zinc oxide eugenol cement. The drugs which were used for the study were Dycal (Caulk Co. U.S.A.), Cavitec (Kerr Co. U.S.A.), Calvital, Nobudyne and Neodyne (Neo Dental Chemical Products). For extirpation, the endodontic cavities were prepared on the lingual surfaces of anterior teeth, and the pulp tissues were extirpated as routine method. After enlarging, irrigation, and measuring of root length by taking X-ray, each root canal filling material was filled in the canal with gutta percha cone, and endodontic cavity was sealed with zinc oxide eugenol cement. Zinc oxide eugenol, $Ca(OH)_2$ (Eli Lilly Co. U.S.A.) and Vitapex (Neo Dental Chemical Products) were used as root canal filling materials. Animals were sacrificed after 1, 3 and 6 weeks following the operation. The teeth were decalcified in formic acid, sectioned and stained with hematoxylin eosin. Microscopic examination revealed as follows. 1. Dycal: The dentin bridge formation was observed at the 3rd week after pulpotomy. Inflammatory conditions which were infiltration of inflammatory cells and dilatation of blood vessels were kept in remaining pulp tissue at the 6th week. 2. Calvital: The dentin bridge was observed at the 1st week after pulpotomy. As the time clasped, the pulp tended to be the fibrous degeneration. 3. Cavitec, Nobudyne and Neodyne: In the case of Cavitec and Nobudyne, the incompleted and irregular dentin bridge was observed at the 6th week, and in Neodyne, was observed at the 3rd week. The severe inflammatory changes were seen in the remaining pulp tissue. As the time clasped, the fibrous degeneration tended to spread in the remaining pulp tissue. 4. $Ca(OH)_2$: Osteocementum was formed at the 3rd week, the matrix of cementum and dentin were resorted, and infiltration of lymphocytes was seen in periapical tissue when $Ca(OH)_2$ was used as canal-filling materials. S. ZOE and Vitapex The cementum like substance was seen in periapical portion at the 1st week, when ZOE and Vitapex were used as root canal filling materials. As the time elapsed, the matrix of cementum and dentin tended to be resorted. At the 6th week, the inflammatory condition of periapical tissue was continued in the case of ZOE, but was reduced in the case of Vitapex.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.352-362
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• 2005

Statement of problem. Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression techniques in internal connection implant systems. Purpose. The purpose of this study was to compare the accuracy of two fixture-level impression techniques in two conditions (parallel and divergent) and to assess the effect of tightening sequences and forces on stresses generated on superstructures in internal connection implant system (Astra Tech). Material and methods. Two metal master frameworks made from two abutments (Cast-to Abutment ST) each and a corresponding, passively fitting, dental stone master cast with four fixture replicas (Fixture Replica ST) were fabricated. Ten dental stone casts for each impression techniques (direct unsplinted & splinted technique) were made with vinyl polysiloxane impressions from the master cast. Strain gauges for each framework were fixed midway between abutments to measure the degree of framework deformation on each stone cast. Pairs of strain gauges placed opposite each other constituted one channel (half Wheatstone bridge) to read deformation in four directions (superior, inferior, anterior, and posterior). Deformation data were analyzed using one-way ANOVA and the Tukey test at the .01 level of significance. And the effect of tightening sequences (right-to-left and left-to-right) and forces (10 Ncm and 20 Ncm) were assessed with ten stone casts made from parallel condition by the splinted technique. Deformation data were analyzed using paired t-test at the .01 level of significance. Conclusions. Within the limitations of this study, the following conclusions could be drawn. 1. Frameworks bent toward the inferior side on all casts made by both direct unsplinted and splinted impression techniques in both parallel and divergent conditions. 2. There was no statistically significant difference of accuracy between the direct unsplinted and splinted impression techniques in both parallel and divergent conditions (P>.01). 3. There was no statistically significant difference of stress according to screw tightening sequences in casts made by the splinted impression technique in parallel condition (P>.01). 4. Greater tightening force resulted in greater stress in casts made by the splinted impression technique in parallel condition (P<.01).

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.523-534
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• 2007

This study is an analysis of types of patients and distribution of implant site and survival rate of $Xive^{(R)}$ implant. The following results on patient type, implant distribution and survival rate were compiled from 324 implant cases of 140 patients treated at the periodontal dept. of Yonsei University Hospital and G dental clinic between February 2003 and April 2006. 1. There are no dissimilarities between men and women, with patients in their 30, 40, 50s accounting for 80% of patients and accounted for 82% of implant treatments; the largest share of patients and implant treatments. 2. Mn, posterior area. accounted for 57% of implant treatments followed by Mx. posterior area(29%), Mx, anterior area(8%) and Mn, anterior area(6%). 3. Partial edentulous patients treated by single crown and bridge-type prosthesis accounted for 96% and fully edentulous patient accounted for the remaining 4%. 4. The major cause of tooth loss is periodontal disease, followed by dental canes, trauma and congenital missing. 5, The distribution of bone quality for maxillae was 54,2% for type III, followed by 30.8% for type II, 15% for type IV and 0% for type I. As for mandible, the distribution was 63% for type II, followed by 34% for type III, 2,5% for type I and 0,5% for type IV. 6. The distribution of bone quantity for maxillae was 55% for type C, followed by 35% for type B, 8% for type D and 2% for type A. As for mandible, the distribution was 60% for type B, followed by 32% for type C, 7% for type A and 0% for type D. 7. The majority of implants were those of 9.5-13 mm in length(95%) and regular diameter in width(82%). 8. The total survival rate was 98%. The survival rate was 97% in the maxillae region and 99% in the mandible region. 9. The survival rate in type I was 83%, in type II was 99%, in type III was 97% and in type IV was 100%. As for the bone quantity, the survival rate in type A and D(100%) was most, followed by type B(99%) and type C(96%). The results showed that $Xive^{(R)}$ implant could be used satisfactorily compare for the other implant system. But we most to approach carefully in certain extreme condition especially with poor bone quality and quantity.

• Journal of Dental Rehabilitation and Applied Science
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• v.20 no.2
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• pp.109-120
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• 2004

INTRODUCTION: The build-up method has been used for application of porcelain powder on the metal framework to make final tooth shape conventionally. This method takes time and need skill to mimic final shade and shape of porcelain fused to metal crown. The purpose of this study was to develop standard shape and shade laminating porcelain forms to reduce build-up time. METHODS: To make tooth form porcelain paste, several liquid organic compounds were added to conventional feldspathic porcelain. The amount of additives and rheologic property were tested to find out best composition. Comparison of mixing methods to reduced porosity, proper heating schedule, and measurement of shrinkage amount and residual organic materials were performed to set-up standard procedures. Finally, biaxial flexural strength and color of preformed laminated paste porcelain were compared with those of porcelain which fabricated by the conventional build-up method. RESULTS: There was no significant difference in physical properties and color stability between two fabrication methods after various testing methods. Conclusion: This new build-up method can be applied to fabricate the PFM crown and bridge without any loss of strength and optical properties.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.214-220
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• 2013

Implant prosthodontics is beneficial for edentulous patients in enhancing the support, retention, stability, phonation and so on. Various types of prosthesis supported by implant, including implant retained- or supported- overdenture for the removable type and ceramo-metal and fixed prostheses with processed acrylic teeth for the fixed type, are frequently used. Treatment planning for the prosthesis with implant must be made after considering individual characteristics such as form of residual ridge, soft tissue, interocclusal relationship, economic status. Fixed prosthesis with processed acrylic teeth (also known as 'implant hybrid prosthesis' or 'bone anchored bridge') has the advantages of both removable and fixed prosthesis such as proper soft tissue profile, esthetic outcome, increased masticatory efficiency and psychological stability. The 73-years-old female patient came to the department of prosthodontics, Dental hospital of Yonsei University. She was diagnosed with Kennedy class I partial edentulism in the maxilla and complete edentulism in the mandible. This article reports a satisfactory clinical and esthetic outcome of full mouth rehabilitation using removable partial denture in the maxilla and implant hybrid prosthesis in the mandible.

• The Journal of Advanced Prosthodontics
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• v.10 no.1
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• pp.18-24
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• 2018

PURPOSE. In literature, many studies compare survival rates of different types of FPDs. Most of them compared restorations, which originated from one university, but from different clinicians. Data about restoration survival rates by only one experienced dentist are very rare. The aim of this study was to evaluate the survival rate of all-ceramic FPDs without the blurring effects of different clinicians. MATERIALS AND METHODS. 153 veneered-zirconia FPDs were observed for follow-up. 22 patients received 131 single crowns and 22 bridges. Because of the different bridge lengths, one unit was defined as a restored or replaced tooth. In total, 201 units were included. Only the restorations performed by the same clinician and produced in the same dental laboratory from 2011 to 2016 were included. Considered factors were defined as "type of unit", "type of abutment", "intraoral region", and "vitality". Modified UHPHS criteria were used for evaluation. Statistical analysis was performed using cox-regression. RESULTS. 189 units (94.0%) showed no kind of failure. 5 chippings (2.4%) could be corrected by intraoral polishing. 4 units (1.9%) exhibited spontaneous decementation. These polishable and recementable restorations are still in clinical use. Chippings or decementations, which lead to total failure, did not occur. One unit was completely fractured (0.5 %). Biological failures (caries, periodontitis or periimplantitis) did not occur. The statistical analysis of the factors did not reveal any significant differences. CONCLUSION. Modern all-ceramic FPDs seem to be an appropriate therapy not only for single restorations but for complex occlusal rehabilitations.

• The Journal of Korean Academy of Prosthodontics
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• v.14 no.1
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• pp.47-54
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• 1976

Pulpal temperature is changed in response for various conditions which were mechanical, thermal, chemical and biological stimuli. This study was performed to determine the pulpal temperature changes which were using air turbine with air-water coolant, water coolant, and conventional dental engine with water coolant and no coolant on 28 canine of dogs. In order to record pulpal temperature, pulp chamber was opened on the labiocervical area of canine. Thermocouple was inserted into pulp chamber and was fixed with filling material(dycal). Changes of pulpal temperature were recorded on the physiograph, which had been standardized temperature degree, through thermocouple to thermistor bridge and carrier preamplifier. The amount of experimental temperature change to that of control was interpreted in the pulpal cavity. The obtained results were as followings: 1. The mean normal temperature was 33.07 centigrade. 2. The temperature was decreased than normal pulpal temperature. It was 12.04 centigrade in reduction by air turbine with air-water coolant, 7.17 centigrade in reduction by air turbine with air coolant, 5.54 centigrade in reduction by conventional engine with water coolant, and 1.26 centigrade in reduction by conventional engine with no coolant. 3. The time for maximal temperature change was 53.3 seconds in reduction by air turbine with air-water coolant, 73.4 seconds in reduction by air turbine with air coolant, 50.9 seconds in reduction by conventional engine with water coolant, and 27.1 seconds in reduction by conventional engine with no coolant. 4.. After reduction was ceased, the recovery time to normal pulp temperature was 287.1 seconds in air turbine with air-water coolant, 189.0 seconds in air turbine with air coolant, 86.9 seconds in conventional engine with water coolant, and 52.9 seconds in conventional engine with no coolant respectively.