• 대한치과기공학회지
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• 제42권4호
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• pp.307-312
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• 2020

Application of ceramic materials for fabrication of dental restoration materials has been a focus of interest in the field of esthetic dentistry. The ceramic materials of choice are glass ceramics, spinel, alumina, and zirconia. The development of yttrium tetragonal zirconia polycrystal (YTZP)-based systems is a recent addition to all-ceramic systems that have high strength and are used for crowns and fixed partial dentures. Computer-aided design/computer-aided manufacturing (CAD/CAM)-produced, YTZP-based systems are popular with respect to their esthetic appeal for use in stress-bearing regions. The highly esthetic nature of zirconia and its superior physical properties and biocompatibility have enabled the development of restorative systems that meet the demands of today's patients. Many in vitro trials have been performed on the use of zirconia; however, relatively fewer long-term clinical studies have been published on this subject. The use of zirconia frameworks for long-span fixed partial dentures is currently being evaluated; in the future, more in vivo research and long-term clinical studies are required to provide scientific evidence for drawing solid guidelines. Further clinical and in vitro studies are required to obtain data regarding the long-term clinical use of zirconia-based restorations.

• 대한치과보철학회지
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• 제42권2호
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• pp.125-132
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• 2004

Statements of problem: All ceramic fixed partial denture cores can be made by the slip casting method and the advanced alumina tape method. The fracture resistance of these core connector areas is relatively low. Purpose: The purpose of this study is to standardize the appropriate volumetric figure and location of the connectors in the alumina core fabricated in alumina tape to be used in fixed partial dentures by way of topology optimization. Material and method: A maxillary anterior three-unit bridge alumina core with teeth form and surrounding periodontal apparatus model was used to ultimately design the most structurally rigid form of the connector. Loadings from a $0^{\circ}$, $45^{\circ}$ and $60^{\circ}$ to the axis of each tooth were applied and analyzed with the 3-D finite element analysis method. Using the results from these experiments, the topology optimization was applied and the optimal reinforcement layout of connector was obtained and the detail shape in the fixed partial denture core was designed. Results: The modified prosthesis with the form of a bulk in the lower lingual surface of the connector in the event, reduced the stress concentration up to 20% in the 3-D FEA. Conclusion: The formation of a bulk in the lower lingual connector area of an alumina core for a fixed partial denture decreases the stress to a clinically favorable measure but does not harm the esthetic point of view. This result illustrates the possibility of clinical application of the modified form designed by the topology optimization method.

• 대한치과보철학회지
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• 제43권2호
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• pp.218-231
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• 2005

Statement of problem. In the partially edentulous patients, removable partial dentures have been working as a important treatment modality. Clasps, a kind of direct retainers, received some amount of stresses during the insertion and removal of partial denture on the abutment tooth. Purpose. The study is to investigate stresses of the different clasps. Material and methods. In order to investigate the degree of stresses, maxillary partial edentulism (Kennedy Class II modification I) was assumed and removable partial dentures were designed on it with three kinds of metallic materials; cobalt-chromium alloy, type IV gold alloy and commercially pure (c.p.) titanium. Aker's clasp was applied on the left second molar. RPA (mesial rest-proximal plate-Aker's) clasp was on the left first premolar and wrought wire clasp was on the right first premolar. Three dimensional, non-linear, dynamic finite element analysis method was run to solve this process. Results. 1. Cobalt-chromium alloy had the highest von Mises stress value and c.p. titanium had the lowest one irrespective of the types of clasps. 2. In the Aker's clasps, stress on the retentive tips was shown shortly after the appearance of stresses of the middle and minor connector areas. These time lag was much shorter in the RPA clasps than in the Aker's clasp. 3. In general. retentive tips of wrought wire clasps had much less amount of stress than other clasps. Conclusion. The amount of stress was the highest in the RPA clasp and the lowest in the wrought wire clasp, in general.

• 대한치과기공학회지
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• 제34권3호
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• pp.291-302
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• 2012

Purpose: It is to survey old men's utilization status of dental clinic and temporary-binding dentures and then to provide basic data to make a program for manufacturing old men's dentures and their teeth health education. Methods: Random selection was made on old men living in Daejeon and Chungnam, and a survey was conducted from April 15 to May 20, 2011. 500 questionnaires were distributed and 420 questionnaires were collected. Using spss 18.0 program, final analysis was made on 363 questionnaires except for 57 questionnaires which had missing value or showed some doubts about the unreliability. Results: 1. With respect to number of natural teeth as per the age, the upper/lower jaws had meaningful differences (P<.001), which means that the older the person is, the smaller number of natural teeth is. In the meantime, there was no meaningful difference according to sex. 2. With respect to kind of prosthetics installed in a mouth as per the age, there was meaningful difference in the upper jaws (P<.05) but there was no meaningful difference in the lower jaws. It was found out that the older the persons are, the more they use removable dentures while the younger the persons are, the more they use fixed partial dentures. 3. With respect to mouth health condition recognized by oneself, it showed bad (44.4%) and good (10.3%),which means recognition as bad is greater, and the age when prosthetics were first used is dispersed variously from below 40 to over 70. 4. Dental care institutions which they mainly used are hospital and clinics (91.5%), and 66.4% of them visited dental clinics lately. Preferential treatment if they go to dentists is as follows in the order of prosthetics (33.9%), gum treatment (24.2%) and pain treatment (14.9%). 5. 68.4% of them revisited dentists after installation of dentures and the reason for revisit is as follows in the order of poorly fitted dentures (35.1%), painful gum 25.9%, regular check-up 25.4% and difficult chewing 9.6%. Conclusion: As our country enters into an aging society, mouth health problem of old men has come to a serious issue, and therefore, a survey was conducted on some old men with respect to their utilization status of dental clinic and removable dentures in order to provide basic data for improvement of quality of their life, maintenance and enhancement of their mouth health. The study result shows that the older they are, the higher the loss rate of teeth as well as needs for prosthetics are, and thus it is thought the study will help to develop mouth health education program which may improve quality of old men's life by recovery of mouth functions declined due to loss of teeth and by regular check-up, education for mouth health control and following-up control of dentures.

• 대한치과보철학회지
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• 제53권1호
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• pp.58-65
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• 2015

완전 무치악 환자의 수복 시 총의치나 임플란트 지지 피개의치와 더불어 임플란트를 지대치로 이용하는 국소의치가 치료 방법의 하나로 고려될 수 있다. 적은 수의 임플란트를 전략적으로 중요한 위치에 식립한 후 가철성 국소의치로 수복할 경우, 임플란트를 통해 안정을 얻고 부가적으로 유지 및 지지를 확보할 수 있을 뿐만 아니라 광범위한 임플란트 식립을 통한 고정성 보철물에 비해 환자의 수술 부담을 줄여줄 수 있으며, 치료비용 절감 효과도 기대할 수 있다. 본 증례는 오랫동안 국소의치를 사용해 온 환자에서 치아 상실 후 잔존 치조골의 상태 및 환자의 요구를 고려하여 임플란트 지지 국소의치를 제작한 증례로서 전치부에 식립한 임플란트는 고정성 보철물로 수복하고 구치부의 짧은 임플란트는 지지 기능만 부여하였다. 또한 의치상과 클래스프를 열가소성 아크릴 레진으로 제작함으로써 기능적, 심미적으로 만족스러운 치료 결과를 얻었기에 이를 보고하는 바이다.

• The Journal of Advanced Prosthodontics
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• 제10권4호
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• pp.286-290
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• 2018

PURPOSE. Conventional resin-bonded fixed partial dentures (RBFPDs) are usually made with a two-retainer design. Unlike conventional RBFPDs, cantilever resin-bonded fixed partial dentures (Cantilever RBFPDs) are, for their part, made with a single-retainer design. The aim of this study was to compare the effect of tooth surface preparation on the bond strength of zirconia cantilever single-retainer RBFPDs. The objective is to evaluate the shear bond strength of these single-retainer RBFPDs bonded on 3 different amount of tooth surface preparation. MATERIALS AND METHODS. Thirty extracted bovine incisors were categorized to 3 groups (n=10), with different amounts of tooth surface preparations. Teeth were restored with single-retainer RBFPDs with different retainer surfaces: large retainer of $32mm^2$; medium retainer of $22mm^2$; no retainer and only a proximal connecting box of $12mm^2$. All RBFPDs were made of zirconia and were bonded using an adhesive system without adhesive capacity. Shear forces were applied to these restorations until debonding. RESULTS. Mean shear bond strength values for the groups I, II, and II were $2.39{\pm}0.53MPa$, $3.13{\pm}0.69MPa$, and $5.40{\pm}0.96MPa$, respectively. Statistical analyses were performed using a one-way ANOVA test with Bonferroni post-hoc test, at a significance level of 0.001. Failure modes were observed and showed a 100% adhesive fracture. CONCLUSION. It can be concluded that the preparation of large tooth surface preparation might be irrelevant. For zirconia single-retainer RBFPD, only the preparation of a proximal connecting box seems to be a reliable and minimally invasive approach. The differences are statistically significant.

• 대한치과보철학회지
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• 제60권2호
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• pp.211-221
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• 2022

완전 무치악 악궁을 수복함에 있어 해부학적인 한계 또는 경제적인 제한이 있거나 환자가 광범위한 수술을 원하지 않을 경우에 임플란트 식립이 제한될 수 있다. 이러한 경우 전악 임플란트 고정성 보철물의 대안으로 임플란트 보조 국소의치를 이용할 수 있다. 본 증례는 치주질환으로 다수 치아를 발거하여 상악 완전 무치악과 하악 부분 무치악이 된 56세 여성 환자에서 상악 전방부에 4개의 임플란트를 식립하여 8본 서베이드 보철물과 임플란트 보조 국소의치로 수복하였고, 하악은 전치부 8본 고정성 가공 의치 및 구치부 임플란트 고정성 보철물로 수복하였다. 9년 간의 경과 관찰 시 심미적, 기능적으로 적절한 결과를 얻었기에 이를 보고하고자 한다.

• 한국CDE학회논문집
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• 제11권5호
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• pp.351-358
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• 2006

Recently, the development of new structural model in fixed partial denture system is required to be started from the conceptual design with low cost, high performance and quality. In this point, a FEM based design of partial denture is used to investigate stress distribution on the durable shape. In this paper, the structural performances of partial dentures were analyzed under three biting forces. The periodontal embedding model is introduced on behalf of the detailed supporting tissue, which is composed of dentin, cortical bone, cancellous bone and periodontal ligament. Using topology optimization, the optimal reinforcement layout of connector was obtained and the detail shape in the fixed partial denture was designed.

• 대한치과보철학회지
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• 제62권1호
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• pp.1-5
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• 2024

목적: 의치를 장착한 환자에서 성별, 연령, 보험적용여부 및 종류, 의치를 장착한 악궁, 의치 종류에 따라 의치 장착 후 사후 점검 횟수에 차이가 있는지 분석하고자 한다. 대상 및 방법:이 연구는 10년 간 일산병원 치과보철과에서 의치를 장착한 만 65세 이상의 환자 988명을 대상으로 하였다. 성별, 연령, 보험 적용 여부 및 종류, 의치를 장착한 악궁, 의치 종류 등의 변수를 고려하여 사후 점검의 횟수와 기간을 평가하였으며, 통계 분석은 5%의 유의수준에서 진행하였다. 결과: 총 988개의 의치가 포함되었으며, 사후 점검 횟수의 중위수는 3으로 나타났다. 남성이 여성보다 유의미하게 (P = .017) 내원 횟수가 더 많았으며, 의치 종류에 따라서는 금속상 총의치가 국소의치보다 유의미하게 (P = .005) 사후 점검 횟수가 더 많았다. 그 외의 변수는 사후 점검 횟수에 영향을 미치지 않았다. 결론: 이번 연구의 한계 내에서 남성 환자와, 금속상 총의치 환자의 경우 의치의 조정 횟수가 증가하였다.

• 구강회복응용과학지
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• 제28권3호
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• pp.309-318
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• 2012

치주질환이 중증도 이상으로 진행되면 대개 많은 량의 치주조직지지가 상실된다. 일부 치아 주변으로 발생되는 이러한 조직 파괴는 그들의 심한 동요 때문에 일부 치아들은 스스로 탈락되거나 발치가 요구되는 단계까지 진행된다. 이러한 경우에 적절한 치주치료와 유지 그리고 교합평형을 고려한 치주-보철 치료를 포함하는 포괄적 치료계획이 그들의 건강, 기능, 심미 등의 수복을 위해 필요하게 되고, 이러한 치주-보철치료 중의 하나인 크로스-아치 고정성국소의치(cross-arch fixed partial dentures, CAFPDs)가 심하게 감소된 치주조직지지를 갖는 치아들의 안정을 위해 사용될 수 있다. 그러나 불행하게 이러한 보철물의 디자인에 따른 생역학적 개념과 교합양식에 대해 아직 많이 알려져 있지 않은 상태이다. 본 논고에서는 교합성외상 그리고 CAFPDs를 통해서 본 Ante's law의 재조명, 치료 원칙, 교합부여, 장기적 예후 등에 대한 정리를 보여줄 것이며 증례를 통해 그 가능성을 제시해 보고자 한다.