• Proceedings of the KACD Conference
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• 2003.05a
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• pp.290-290
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• 2003

지난 20세기 동안, 치아 우식에 대한 치료는 G.V. Black이 제안한 '예방 확대' 개념에 따른 와동형성 원칙에 따라 외과적 치칠 삭제의 형태로 수행되어져 왔다. 즉, 치아 우식 병소에 발견되면 치과의사들은 망설임 없이 핸드 피스를 들고 우식 부위 치질을 삭제하며, 수복재료에 따라 적합한 형태로 건전한 치질을 삭제하여 수복 와동을 형성하였다. 그러나 치아 우식에 대한 많은 연구 결과, 원인균과 산 생산 및 탈회와 재석회화 등에 대한 정보가 알려졌고, 접착 수복이 비약적 발전을 하여 임상 적용이 일반화되면서, 지난 10여년 이래 치아 우식에 대한 치료 개념이 점차 최소 치질 삭제와 건전 치질 보존으로 전환되어 왔고 이러한 개념을 통칭하여 Minimal Intervention Dentistry라 하고 있다. 21세기에는 치아 우식에 대한 치료가 minimal intervention dentistry의 개념 하에 점차 폭넓게 임상에 적용될 것으로 예상되며, 다음과 같은 원칙들이 제시되고 있다.(중략)

• Composites Research
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• v.28 no.1
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• pp.6-14
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• 2015

Polymerization shrinkage stress analysis of dimethacrylate-based composite (Clearfil AP-X, Kuraray) and silorane-based composite (Filtek P90, 3M ESPE) used for dental composite restorations was performed using strain-gage measurement and FEM analysis. A theoretical equation based on Young's modulus and polymerization shrinkage of the composite resin was proposed to predict the polymerization shrinkage stress. Experimental results showed that the maximum shrinkage stress of Clearfil AP-X was about 2.8 times higher than Filtek P90. FEM analysis agreed with such experimental stress behaviours and showed that the maximum Von-Mises stress appeared near the margin of the filled resin adhered with PMMA ring. The stress concentration at the interface on the specimen surface was higher than that in the interior. The maximum error of shrinkage stress by the theoretical equation was reasonable within 5% in comparison to FEM results under plane stress.

• Journal of Dental Rehabilitation and Applied Science
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• v.20 no.2
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• pp.121-134
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• 2004

This article describes a clinical protocol for the conventional rehabilitation of patient diagnosed with partial anodontia. A combined dental therapy approach was used and included endodontic therapy and root capping on the maxillary central incisors, fabrication of a maxillary overdenture, and fabrication of mandibular konus overdenture supported by 3 konus abutments. Within this protocol, tooth-supported overdenture prostheses are used for 2 purposes: first, to obtain the most rigid retention and function at an established maxillary-mandibular relationship; and second, to continuously maintain function and esthetic appearance applying immediate dentures after teeth extraction. The idea behind this protocol and its associated clinical procedures is presented along with a discussion compared with implant therapy. In the case introduced, and after 7 years of observation, the therapy can be seen as a success. We increased the occlusal vertical height in this case, but it would be more appropriate to see this as recovering the occlusal vertical height that was lost. The process of increasing the occlusal vertical height, that is restoration of the face, modification of the extrinsic occlusion of the incisors, and retraction of the mandible is very difficult and important. Ultimately, class III malocclusion is fixed, adequate occlusal vertical height is gained, and the retracted posterior anodontial portion is restored by prosthodontic dentures based on the rigid support theory. The result of the therapy done on the later-achieved malocclusion with partial anodontia on the posterior portion must consider the following in order to maintain the safety of the esthetics of the tooth and face for a period of time: 1) occlusal restoration with an ideal occlusal vertical height, 2) allowance of the final occlusion induced by the functional relationship of the upper and lower jaw, 3)final occlusion functionally induced by the lip competence limit.

• The Journal of the Korean dental association
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• v.50 no.7
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• pp.368-376
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• 2012

The demand for tooth-colored restorations has grown considerably during the last decade. Posterior composite restorations have risen in popularity as a result of the development of improved resin composites, bonding systems and operating techniques. A major limitation of direct composite restoration is the difficulty of controlling the polymerization shrinkage. To overcome this limitation, the indirect fabrication of a composite restoration and cementation with resin cement has been advocated. Unfortunately, the current available resin cements with indirect restorations do not always bond to dentin as strongly as dentin adhesive systems bond with direct resin composite restorations. Several procedural strategies have been proposed for indirect composite restoration. In this regard, the rationale for the indication, characteristics and clinical application is described in this paper. As a result, we will try to suggest the evidence-based guidelines for indirect composite restorations by reviewing each available indirect composite products, technical procedure and pronosis.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.177-180
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• 2000

소나 시스템에서는 신호 대 잡음비의 향상, 표적의 방위탐지 및 위치 데이터 산출, 간섭신호 제거 등을 위하여 지향성 빔을 만들어 사용한다. 본 논문에서는 선형으로 배열된 센서에서 각 센서쌍들에 대한 상호상관 행렬을 이용한 SCCBF(Spatial Cross Correlation Beamformer) 알고리즘을 제안하였다 이상적인 조건하에서 제안된 SCCBF는 CBF(Conventional Beamformer)에 비해 3dB의 Array Gain을 갖는 것을 이론적으로 검증하고 표적의 탐지 방위정확도를 나타내는 빔폭(Beam Width)이 CBF 보다 0.5배정도가 됨을 검증하고 모의실험을 통하여 이를 입증하였다.

• Korean Journal of Heritage: History & Science
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• v.47 no.3
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• pp.208-223
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• 2014

Since the recent restoration of the Sungnyemun gate (South gate of Seoul) which was burnt down in 2008, there were dispute about the application of traditional technique for the conservation of cultural heritage. In this research, the definition of traditional technique for cultural heritage conservation is thought and mentioned. In general, the understanding of traditional technique is based on the idea of 'tradition'. Tradition is not defined as a 'eternal doctrine existence', but a 'development of succession' and a 'living existence'. Thus 'traditional performance and craft as intangible cultural heritage' is defined as 'intangible' which also makes it difficult to define the 'original form/state' from 'the conservation of the original form' which is a major principle of cultural heritage. In case of Korea, if the 'traditional technique as intangible cultural heritage' is put into application to cultural heritage conservation, the unclear definition will cause many problems in the restoration/conservation site. This is because the site will apply this technique without any discussion of the range and limitation of 'traditional technique'. This means there will be the lack of discussion for the conservation of the cultural heritage which will not have a strict criteria for the allowable range of usage for the 'traditional material' using the vaguely defined 'traditional technique'. In this study, these application issues of the traditional technique were also considerecl, comparing the development of international wnservation principles. As a result, the conservation of 'traditional technique as intangible cultural heritage' is important, but the 'technique left inside the tangible cultural heritage' which is the 'material which is carrying the technique when it was firstly built' has more importance to preserve and need to be in the major considerations.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.209-222
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• 2011

Missing anterior teeth can be replaced using any of a number of methods. Patients may choose to replace missing teeth with a prosthesis that is either removable, fixed, or retained with implants. For patients faced with financial, anatomical, and/or esthetic limitations, the edentulous region can be restored successfully and esthetically with a properly designed and fabricated rotational path RPD. The rotational path RPD is a partial removable dental prosthesis that incorporates a curved, arcuate, or variable path of placement allowing one or more of the rigid components of the framework to gain access to and engage an undercut area. The rigid retainer must gain access to the infrabulge portion of the tooth by rotating into place. Either a minor connector or proximal plate provides retention through its intimate contact with a proximal tooth surface. A specially designed dovetails or asymmetric rest seats provides support and embracing effects. Correctly designed and fabricated rotational path RPD can provide improved esthetics, cleanliness, and retention. But rotational path RPDs are technique sensitive since the rotational path RPD has little margin of laboratory error that rigid retainers cannot be adjusted like conventional clasps can, RPD framework must be remade once the retention is lost. The sufficient understanding of the concept for the rotational path RPD is required for clinically successful treatment. This clinical report describes in detail the theoretical, laboratory considerations and the treatment of a patient with an anterior maxillary edentulous area treated by an AP path rotational RPD that had a difficulty in long term maintenance and describes another clinical case in which more reasonable treatment procedures were approached after analyzing the former case.

• Journal of Dental Rehabilitation and Applied Science
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• v.20 no.2
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• pp.95-107
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• 2004

The prosthodontic treatment of Class II division 2 malocclusions is challenging. Ideally, these malocclusions should be identified at an early age and corrected with orthodontic treatment; otherwise, the individual develops a habitual position characterized by deep overbite and significant retruded position of mandibular condyle at the TMjoint fossa. This article describes a clinical protocol for the occlusal rehabilitation of patients with Class II div.2 malocclusions. Within this protocol, an occlusal splint was used to locate the most suitable maxillary-mandibular relationship for function and range of motion. The splint increased the vertical dimension and reduced pain on TMjoints. After transfer this relationship to an articulator for fabrication of provisional restorations, the CR position and centric prematurity contact between maxilla and mandible was used to determine the tentative vertical dimension of occlusion(VDO). The amount of elevation of VDO was decided on the articulated model. The provisional restorations were accurately transfered to a patient's mouth in clinical procedures using tattoo points. The final restoration was delivered after some trial periods with provisional restorations. The theory behind this protocol and its associated clinical procedures is presented along with a discussion.

• The Journal of the Acoustical Society of Korea
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• v.20 no.7
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• pp.31-36
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• 2001

Passive sonar system forms the various beams in any desired directions to obtain the improvement in Signal-to-Noise (S/N) ratio, bearing detection and localization of targets, and the attenuation of interferences from other directions. The improvement of beamforming is very important to detect modern underwater targets as noise reduction technology leads to considerably low-level acoustic emissions in the long range in complex environmental sea. In this paper, we proposed the spatial cross correlation beamforming (SCCBF) algorithm using cross correlation matrix of individual hydrophone pairs of linear array sensors. By the theoretical analysis and simulation, the proposed SCCBF is demonstrated that its performances compared to conventional beamforming (CBF) output can be obtain above 3dB of array gain and about half of beam width represented the bearing accuracy in target detection. Also, this paper presents sea test result of linear passive sonar system that the proposed algorithm implemented.