• 대한치과의사협회지
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• 제54권1호
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• pp.21-26
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• 2016

The requirements for the successful treatment of all-ceramic restorations are not so different from the ones of conventional restorations. "The provisional restoration followed by an adequate tooth reduction" and "the accurately fitting prostheses with corresponding to final impression" can be the examples of them. Nevertheless, the one which all-ceramic restorations are distinguished from conventional restorations is the additional procedure of so called "bonding". In addition to the application of resin cement between "inner surface of restoration and outer surface of abutment", bonding technology can be also applied to the treatment process of "Post and Core" in particular if the abutments are non-vital teeth. Core build-up for all-ceramic crown is conducted with fiber post and tooth colored composite by considering the properties of the restorations transmitting light. I would like to share my clinical experience about "silica based ceramic and non silica based ceramic restoration.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1996년도 Proceedings International Workshop on New Video Media Technology
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• pp.35-40
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• 1996

In this paper, a method for 3-D surface reconstruction with two real cameras is presented. The method, which combines the extraction of binocular disparity and its interpolation can be applied to the synthesis of images from virtual viewpoints. The synthesized virtual images are as natural as the real images even when we observe the images as stereoscopic images. The method opens up many applications, such as synthesizing input images for multi-viewpoint 3-D displays, enhancing the depth impression in 2-D images and so on. We also have developed a video-rate stereo machine able to obtain binocular disparity in 1/30 sec with two cameras. We show the performance of the machine.

• 대한의용생체공학회:의공학회지
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• 제14권3호
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• pp.235-242
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• 1993

In the early stage of sacroilitis, it is'difficult to detect sacroiliac(Sl) abnormalities by conventional plain X-ray even though there are characteristic symptoms of ankylosing spondylitis. 3 dimensional volume rendering from the CT image was performed to make an early de tection of the structural changes of Sl joint. 2 cases who had clinical impression of ankylosing spondylitis without sacroilitis in plane X-ray and 1 case of typical ankylosing spondylitis as well as 1 case of normal control were studied. The Sl Joints were separated and each joint surface of sacrum and ilium was independently reconstructed by a special 3D manipulation program. All 2 patiant who complained of inflammatory lower back pain with no abnormal findings in the plain X-ray showed structural changes in 3 dimensionally reconstructed surface Image of the Sl joint compared to the normal control. Authors tried several parameters, such as fourler analysis of each surface and the mean and variance of Sl joint gap. We couldn't tell the statistical significance because of the limited number of cases. However, the parameters showed difference according to the progression of disease.

• 구강회복응용과학지
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• 제35권1호
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• pp.27-36
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• 2019

목적: 치과 치료에 사용되는 일부 비위험 기구들에 대한 치과의사의 감염 관리 인지도와 감염 관리 실태를 조사하고자 하였다. 연구 재료 및 방법: 대전광역시, 충청남도, 충청북도 및 전라북도 지역의 40개 치과 병, 의원을 연구 대상으로 하였다. 감염 관리에 대한 치과의사의 인지도와 실천정도에 관해서 설문 조사를 시행하였고, 연구 대상인 치과의사가 치과 치료에 사용하는 인상용 건, 광중합기, 3-way syringe, 색조 견본, 치실통의 표면 오염도를 아데노신 3인산 측정기를 이용하여 측정하였고, 감염 관리에 대한 인식도와 실태 간의 상관관계를 분석하였다. 결과: 감염 관리에 관한 인지도와 시행 빈도는 3-way syringe에서 가장 높았다. 모든 기구에서 소독액을 사용한 표면 소독이 가장 많이 시행되었다. 표면 오염도는 3-way syringe, 색조 견본이 인상용 건, 광중합기, 치실통보다 낮게 나타났다. 결론: 치과 치료에 사용되는 비위험 기구들 중에서 3-way syringe는 사용자의 감염 관리 인지도와 표면 오염도 간에 유의한 상관관계가 있으며, 감염 관리의 인지도가 높을수록 표면 오염도가 낮은 것으로 나타났다.

• 대한치과보철학회지
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• 제34권2호
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• pp.363-372
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• 1996

A common site of fracture in maxillary complete denture is on the anteroposterior midline that coincides with the notch for relief of the labial frenum. Various approaches to reduce the incidence of this type of fracture have been suggested. The most widely used technique is the reinforcement of acrylic resin denture base with several solid metal forms. But few comparative studies on the efficacy of metal reinforcements have been reported. This study was conducted to compare reinforcing effects of commonly available metal reinforcements, which include wire, metal mesh embedded in the denture base and metal plate affixed to the impression surface of denture base by silicoating technique. This was load on the posterior. The strain gauges were oriented perpendicular to the anteroposterior midline of maxillary polished denture surface at one labial and the four palatal sites Non-renforced denture was used as control. The results were as follows : 1. In the non-reinforced denture group, only tensile strains on the palatal polished surface were observed. The tensile strains decreased in the order of incisive papilla, posterior denture border area, mid palatal area and rugae area. Compressive strain was observed on the labial polished surface. 2. As compared with the non-reinforced denture group, the metal plate or the metal mesh reinforced denture groups showed reduced palatal tensile strains,and the metal mesh reinforcement had a better reinforcing effect than the metal plate. But both reinforced denture groups showed no difference in the amount of compressive strain on the labial polished surface when compared to the non-reinforced denture group. 3. The metal wire positioned just above the labial notch decreased the compressive strain on the labial polished surface. But the presence of metal wires in the palatal polished surface caused increase in tensile strains in the area.

• The Journal of Advanced Prosthodontics
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• 제9권4호
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• pp.252-256
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• 2017

PURPOSE. This in vitro study aimed to analyze and compare the reproducibility of zirconia and lithium disilicate crowns manufactured by digital workflow. MATERIALS AND METHODS. A typodont model with a prepped upper first molar was set in a phantom head, and a digital impression was obtained with a video intraoral scanner (CEREC Omnicam; Sirona GmbH), from which a single crown was designed and manufactured with CAD/CAM into a zirconia crown and lithium disilicate crown (n=12). Reproducibility of each crown was quantitatively retrieved by superimposing the digitized data of the crown in 3D inspection software, and differences were graphically mapped in color. Areas with large differences were analyzed with digital microscopy. Mean quadratic deviations (RMS) quantitatively obtained from each ceramic group were statistically analyzed with Student's t-test (${\alpha}=.05$). RESULTS. The RMS value of lithium disilicate crown was $29.2\;(4.1){\mu}m$ and $17.6\;(5.5){\mu}m$ on the outer and inner surfaces, respectively, whereas these values were $18.6\;(2.0){\mu}m$ and $20.6\;(5.1){\mu}m$ for the zirconia crown. Reproducibility of zirconia and lithium disilicate crowns had a statistically significant difference only on the outer surface (P<.001). The outer surface of lithium disilicate crown showed over-contouring on the buccal surface and under-contouring on the inner occlusal surface. The outer surface of zirconia crown showed both over- and under-contouring on the buccal surface, and the inner surface showed under-contouring in the marginal areas. CONCLUSION. Restoration manufacturing by digital workflow will enhance the reproducibility of zirconia single crowns more than that of lithium disilicate single crowns.

• 대한치과보철학회지
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• 제52권4호
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• pp.346-351
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• 2014

흡착 의치는 의치상연 주위 전체를 가동 점막으로 봉쇄하여 연하나 교합 시 의치상 내면에 일시적으로 음압을 형성하여 의치의 유지와 안정을 강화한다. 본 증례의 환자는 81세의 남자 환자로 새로운 의치를 제작하고 싶다는 주소로 내원하였다. 의치의 유지와 저작 효율에 대한 환자의 높은 요구도를 고려하여 흡착 의치를 통한 총의치 제작을 계획하였다. 하악 후구치 융기 부위를 가압하지 않은 채로 예비 인상을 채득 후 상하악 진단모형을 제작하였다. 이후 개인 트레이 제작 후 최종 인상 채득과 동시에 고딕 아치 기록을 시행하여 중심위 및 수직 고경을 채득하였으며, 상악에는 해부학적 치아, 하악에는 비해부학적 치아를 배열하여 설측 교합을 형성하였다. 이상과 같이 완전 무치악 환자에서 하악 흡착 의치를 통한 총의치 수복은 만족스러운 유지와 기능을 회복할 수 있었기에 본 증례를 보고하고자 한다.

• The Journal of Advanced Prosthodontics
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• 제9권2호
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• pp.124-129
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• 2017

PURPOSE. This study evaluated the effect of span length on the adaptation of implant-supported cobalt chromium frameworks fabricated by three techniques. MATERIALS AND METHODS. Models with two solid abutment analogs at different inter-abutment distances were digitized using a laboratory scanner. Frameworks of two-, three-, and four-unit fixed prostheses were designed by a computer. Six dots with a diameter of 0.2 mm were preset on the surface of each framework. A total of 54 implant-supported cobalt chromium frameworks were fabricated by milling, selective laser melting (SLM), and cast techniques. The frameworks were scanned and exported as Stereolithography files. Distances between two dots in X, Y, and Z coordinates were measured in both the designed and fabricated frameworks. Marginal gaps between the framework and the abutments were also evaluated by impression replica method. RESULTS. In terms of distance measurement, significant differences were found between three- and four-unit frameworks, as well as between two- and four-unit frameworks prepared by milling technique (P<.05). Significant differences were also noted between two- and three-unit frameworks, as well as between two- and four-unit frameworks prepared by cast technique (P<.05). The milling technique presented smaller differences than the SLM technique, and the SLM technique showed smaller differences than the cast technique at any unit prostheses (P<.05). Evaluation with the impression replica method indicated significant differences among the span lengths for any fabrication method (P<.05), as well as among the fabrication methods at any unit prostheses (P<.05). CONCLUSION. The adaptation of implant-supported cobalt chromium frameworks was affected by the span length and fabrication method.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.369-373
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• 2013

PURPOSE. The objective was to evaluate canine positions, intercanine tip width (ICTW) and width of distal surface of canine (WDC), related to facial landmarks including interalar width (IAW), intercommissural width (ICoW), and distance between left and right projection lines drawn from inner canthus of eyes to alae of the nose (DPICa) in a group of Thai. MATERIALS AND METHODS. One hundred Thai subjects aged 18-35 years were selected. IAW and ICoW were measured on subject's face using digital vernier caliper. Irreversible hydrocolloid impression of the upper arch was taken, and a cast was poured with dental stone. Silicone impression material was used to take imprint of the incisal edge of upper six anterior teeth. DPICa was obtained from the subject's face using custom-made measuring equipment and marked on the silicone incisal imprint. The marks were then transferred from the imprint to the stone cast and measured with digital caliper. The ICTW and WDC were also measured on the stone cast. Pearson's correlation was used to determine the correlation. RESULTS. The results revealed that the correlation between ICTW-ICoW was 0.429 and ICTW-DPICa was 0.573. The correlation between WDC-ICoW was 0.426 and WDC-DPICa was 0.547. However, IAW did not show any correlation with ICTW or WDC (P>.05). CONCLUSION. The correlation between canine position and facial landmarks was found. ICTW and WDC had relationship with ICoW and DPICa. DPICa showed stronger correlation with the position of maxillary canine than that of ICoW.

• 한국동물위생학회지
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• 제34권1호
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• pp.55-61
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• 2011

Dermatopathologic findings on cutaneous streptothricosis (bovine dermatophilosis) were conducted in Dinajpur of Bangladesh for one year. The animals were examined clinically at hospital during the physical visit of the affected animals and clinical manifestations and patients' history were recorded. The gross lesions were systematically examined, noted and categorized. An impression smear was made by the skin scraps, stained with Gram's stain and examined microscopically for the presence of causative bacteria. The suitable sizes of skins of 3 animals typically affected with dermatophilosis were collected surgically from the animals, and prepared for the histopathological study. The cardinal clinical features and gross lesions were characterized as paint-brush cutaneous surface with matted hairs, scab and crust formation, roughened coat; istopathologically as hyperkeratosis, parakeratosis, typical "palisading encrustations", extensive proliferation of coccoid shaped, bluish coloured bacteria (zoospores) in the cells of the outer rootsheath of the hair follicles, separation of keratinized layer from the epidermal epithelium, epidermal hyperplasia, densely cellular dermis with moderate destruction of glandular structures. Coccoid shaped gram positive organisms which form multidimensional arrangement were also observed by impression smear. The clinical signs, gross lesions, morphology of the organisms, staining properties, and histopathological features of the affected skin were diagnostic criteria for the bovine cutaneous streptothricosis.