• 대한치과기공학회지
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• 제7권1호
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• pp.33-40
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• 1985

When full denture is being fabricated, pronounciation, recovery of aesthetics of function and mastificatory function should be satisfies for patients. To satisfy for the function of denture, following is the difference between this new way of fabricating and formerly one of it. 1. The size of fabricating tooth which is harmony of original oral structure for patients is deaded by manufacturing labial index and artificial tongue. 2. By the use of artificial tongue and labial index, the arranges of artificial tooth is to become harmony of oral structure. 3. Formation of gingival decided functional impression which is used by impression paste, is harmony of oral structure. Therefore, this full denture can be satisfied with pronouncing oral function of recovery of aesthetics as well as mastificatory through physiological movement of oral tissue not disturbed with anything but cooperated drastically. In manufacturing of this full denture, both dentist and dental technician under cooperation need to proceed the work on the base of importance of communication.

• 대한치과보철학회지
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• 제22권1호
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• pp.51-68
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• 1984

The purpose of this study is primarily to test the use value of tooth ash as an alternative material of the synthetic hydroxyapatite. For this purpose the author performed the experimental study to investigate the phsyical properties of sintered tooth ash and its histocompatibility in vitro. The tooth ash was made by incinerating procedure at $650^{\circ}C,\;750^{\circ}C,\;850^{\circ}C,\;950^{\circ}C\;and\;1050^{\circ}C$ respectively. The composition of tooth ash was analyzed and X-ray diffraction was done. The experimental specimens were molded to the cylinderical form 1 cm high, 1 cm in diameter under the pressure of $1000kg/cm^2$, which were divided into two groups; the one is sintered tooth ash at $1100^{\circ}C$ and the other is fired mixture of tooth ash and dental porcelain mixed to the weight ratio of 4:6, 5:5, 6:4 and 7:3. The physical propoerties of the sintered specimens were examined and their microstructure was observed under the Scanning Electron Microscope. The results obtained were as followings: 1. The difference of the tooth ash composition depending on incinerating temperature was of no significance, but the $CO_2$ disappeared from $950^{\circ}C$. 2. X-ray diffraction showed the tooth ash was mainly composed of hydroxyapatite and a small amount of - white lockite. But phase transformation was not disclosed. 3. The microstructure of the sintered specimens of the ashed tooth powder was of no difference in the structure and grain size accompanying the ashed temperature, but sintering ability seemed to be the best in the specimen incinerated at $950^{\circ}C$. 4. There was good wettability in the mixed sintered specimens of the ashed tooth powder and the porcelain powder. 5. The compressive strength of the sintered specimens of the tooth ash incinerated at $950^{\circ}C$ was the highest with $589.75kg/cm^2$ and the porosity and the absorption were the lowest as well. 6. The mixed sintered specimens of the tooth ash and porcelain powder was good in the physical properties in the case of mixed weight ratio of 6:4. 7. The animal fibroblast cultures with porcelain showed increase in the cell number, whereas the tooth ash showed a small degree of growth inhibition. But the difference of cell multiplication efficiency between control cultures and test cultures with tooth ash was not observed.

• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.150-161
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• 2022

PURPOSE. The purpose of the study was to assess the influence of build orientations and density of support structures on the trueness of the 3D printed removable partial denture (RPD) frameworks. MATERIALS AND METHODS. A maxillary Kennedy class III and mandibular class I casts were 3D scanned and used to design and produce two 3D virtual models of RPD frameworks. Using digital light processing (DLP) 3D printing, 47 RPD frameworks were fabricated at 3 different build orientations (100, 135 and 150-degree angles) and 2 support structure densities. All frameworks were scanned and 3D compared to the original virtual RPD models by metrology software to check 3D deviations quantitatively and qualitatively. The accuracy data were statistically analyzed using one-way ANOVA for build orientation comparison and independent sample t-test for structure density comparison at (α = .05). Points study analysis targeting RPD components and representative color maps were also studied. RESULTS. The build orientation of 135-degree angle of the maxillary frameworks showed the lowest deviation at the clasp arms of tooth 26 of the 135-degree angle group. The mandibular frameworks with 150-degree angle build orientation showed the least deviation at the rest on tooth 44 and the arm of the I-bar clasp of tooth 45. No significant difference was seen between different support structure densities. CONCLUSION. Build orientation had an influence on the accuracy of the frameworks, especially at a 135-degree angle of maxillary design and 150-degree of mandibular design. The difference in the support's density structure revealed no considerable effect on the accuracy.

• 대한소아치과학회지
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• 제43권2호
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• pp.192-199
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• 2016

유치열에서 드물게 관찰되는 삼중치는 세 치아의 비정상적인 융합으로 나타난다. 몇몇 문헌들에서 이중치에 대해 보고하고 있지만, 삼중치에 대한 보고는 매우 드물다. 이러한 다중치는 유치열에서 더 흔하게 관찰되며, 몇 가지 임상적 문제점을 나타낸다. 심미적인 문제 뿐만 아니라 치아 우식증 및 파절에 취약함, 영구 치배의 결손, 교정적, 치주적 문제를 야기할 수 있으며, 복잡한 치아 구조로 인해 치수 치료를 어렵게 한다. 첫 번째 증례는 만 1세 7개월 남아의 상악 유전치부에 나타난 삼중치로, 깊은 우식으로 치수 치료가 필요할 것으로 예상되었고, Mineral Trioxide Aggregate (MTA)를 이용하여 부분 치수 절단술을 시행하였다. 두 번째 증례는 만 1세 9개월 남아의 하악 유전치부에 나타난 삼중치로 파절을 주소로 내원하였다. 파절편 조각을 제거한 뒤, 잔존 치아에서 치수 절제술을 시행하였다. 각각 24개월, 6개월간의 정기 검진시까지 특별한 합병증은 나타나지 않았으며, 수복물 또한 비교적 양호하게 유지되었다.

• 대한치과보철학회지
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• 제59권3호
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• pp.319-332
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• 2021

심미적인 도재 재료와 레진 시멘트의 비약적인 발전으로 임상에서 금속도재관에서 전부도재관으로의 전환이 활발히 이루어지고 있으며, 도재 수복물 제작 시 그에 적합한 형태와 기술을 이용하여야 그 장점을 최대화할 수 있다. 최근 법랑질을 최대한 보존하고 접착 효율을 높이는 최소 침습적 치아 삭제법을 적용하여 치은 연상 변연을 가진 심미적인 도재 부분피 개관 수복방법이 소개되었는데, 이를 통해 치질 삭제의 최소화, 시멘트 제거의 용이성 등 여러 장점들을 얻을 수 있다고 보고된다. 또한 이 제작법은 치은 압배사의 삽입이 불필요하여 치은 압배사 삽입에 소요되는 시간을 절약할 수 있으며 환자의 불편감도 감소시킬 수 있다. 더 나아가 치은 열구액이나 혈액의 개입 없이 명확하게 변연을 채득할 수 있어 더 정확한 수복물 제작이 가능하다고 보고된다. 본 증례에서는 각각 해당 치아 부위에 부분적인 결함이 있는 환자에서 통상적인 전부피개관이 아닌 접착치의학 개념에 따른 최소 침습적 치아 삭제법을 적용한 치은 연상 변연 도재 부분피개관으로 다양한 제작 방법을 활용하여 수복함으로써 불필요한 치아 삭제를 방지하고 잔존 치질을 최대한 보존할 수 있었다. 치료 후 환자와 술자 모두 심미적, 기능적으로 만족할 만한 결과를 얻었기에 이를 보고하는 바이다.

• 대한치과의사협회지
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• 제36권7호통권350호
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• pp.476-483
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• 1998

• 대한심미치과학회지
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• 제7권1호
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• pp.6-17
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• 1998

치아미백은 100여년전 이상부터 시행되어 왔으나, 지난 4반세기 동안의 생활치아 미백술의 표준적인 방법은 과산화수소와 열원을 사용하거나, 열원과 광원을 복합해서 사용하는 것이었다. 이 술식의 단점은 술식의 복잡성, 많은 비용, 결과의 불확실성과 환자의 불편이었다. 1989년 3월에 치과계에서는 Haywood와 Heyman에 의해 발표된 새로운 생활치아 미백술(Night Guard Vital Bleaching)을 도입했다. 치아구조에 대한 carbamide peroxide의 화학적 효과를 알고 있었으면 수년 전에 개발되었을 아주 간단한 치료술식이다. 이 방법은 시술이 쉽고, 사용 되는 재료의 높은 안전성, 낮은 치료비, 높은 성공률로 최근 다시 치아미백 붐을 일으키는데 일조를 하고 있으며, 생활치아 미백술의 표준적인 방법으로 신속히 자리잡아가고 있다.

• 대한치과보철학회지
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• 제34권4호
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• pp.780-790
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• 1996

The endodontically treated tooth is generally restored with post and core, owing to the brittleness and the loss of large amount of tooth structure. Although there have been lots of studies about the endodontically treated teeth, the three-dimensional quantitative studies about the stress distribution of them are in rare cases. In this study, it was assumed that the coronal portion of the upper incisor had extensively damaged. After the root canal therapy it was post cored, and restored with PFG crown. The three-dimensional model, in which the root was supported with a normal alveolar bone, was constructed. Force was applied to the centric stop point with the angle of 135 degrees to the long axis of the tooth. Force was assumed to be 250N as functional maximum bite force of upper central incisors. The results analyzed with three-dimensional finite element method were as follows : 1. Stress was concentrated on the middle portion of the labial side dentin and the apical portion of the dentin. 2. Stress in the post was more concentrated on the post apex. 3. The displacement of the post at the post-cement interface was almost symmetrical la-bio-lingually. 4. It assumed that restoring extensively damaged tooth with a post-core and PFG crown is an adequate method of restoration.

• 대한치과보철학회지
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• 제31권4호
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• pp.468-481
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• 1993

The Purpose of this study was to analyze the stresses and displacements of various post and core. The Finite element models of central incisors were divided into seven types according to the various amount of remaining tooth structures. $10kgf/mm^2$ force was applied respectively as follows : 1) Horizontal on the labial surface 2) $26^{\circ}$ diagonal direction on the lingual surface. Material property, geometry, and load condition of each model were inputted to the two dimensional ANSYS 4.4A finite element program : stresses and displacements were analyzed. Results were follows : 1. In the case of $130^{\circ}$ shoulder post and core, Maximum tensile and shear stresses were observed in the crown margin. 2. Maximum shear stress was about 29% reduced by contrabevel. 3. In the case of 1mm axial tooth structure, Maximum tensile stress observed in the dentin. 4. In the case of but joint of cervix, Maximum stress concentration was observed in the dentin by the inclined and horizontal force. 5. Horizontal force produced the extraordinary high stresses in dentin and supporting structures. 6. The amount of remaining tooth structure affected the level of stress significantly and it determined the location of stress concentration.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.413-422
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• 1993

The purpose of this study was to evaluate the adaptation of light cured glass ionomer cement and composite resin using all- etch technique to tooth structure. In this study, class V cavities were prepared on the buccal surfaces of 10 extracted human premolar teeth with cementum margin and teeth were randomly assigned 2 groups of 5 teeth each. The cavities of glass ionomer cement group were filled with the light cured glass ionomer cement(Fuji II LC) and the cavities of composite resin group were filled with the light cured composite resion(P - 50) using all- etch technique with All- Bond 2. The restored teeth were stored in 100 % relative humidity at $37^{\circ}C$ for 48 hours. And then, the roots of the teeth were removed with the tapered fissure bur and the remaining crowns were sectioned occlusogingivally through the center of restorations. Adaptation at tooth - restoration interface were assessed occlusally, gingivally, and axially by scanning electron microscope. The results were as follows : 1. The adaptation to enamel walls of composite resin restorations using All - Bond 2 showed better than glass ionomer restorations. 2. The adaptation to gingival and axial walls of glass ionomer restorations showed better than composite resin restorations using All - Bond 2. 3. In both groups, occlusal margins of restorations showed better adaptation than gingival margins of restorations.