• 구강회복응용과학지
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• 제40권2호
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• pp.72-81
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• 2024

목적: 본 연구의 목적은 가철성 다이 시스템으로 제작된 작업 모형과 솔리드 작업 모형을 이용해 치과용 캐드캠 시스템(CAD/CAM)으로 제작된 지르코니아 3본 고정성 치과 보철물의 변연 및 내부 적합성을 평가하고자 하였다. 연구 재료 및 방법: 하악 우측 제1소구치와 하악 우측 제1대구치에 지르코니아 크라운을 위한 치아 삭제 프로토콜을 수행하고, 하악 우측 제2소구치가 없는 레퍼런스 모델을 만들었다. 레퍼런스 모델은 폴리비닐 실록산 인상체를 사용하여 복제되었고, 일반적인 치과 기공 절차에 따라 20개의 작업 모형이 제작되었다. 비교 분석을 위해, 10개의 지르코니아 3본 고정성 치과 보철물은 가철성 다이 시스템에서, 나머지 10개는 솔리드 작업 모형에서 제작되었다. 모든 작업 모형은 치과용 데스크탑 스캐너를 사용하여 디지털화되었고, 캐드 소프트웨어에서 보철물을 설계하였다. 최종 3본 고정성 치과 보철물은 밀링 과정을 통해 제작되었다. 변연 및 내부 적합도 평가는 레퍼런스 모델에 제작된 보철물을 위치시키고, 디지털 평가 방법으로 적합도가 측정되었다. 두 그룹 간의 통계 비교를 위해 Mann-Whitney U 검정이 적용되었다(α = 0.05). 결과: 가철성 다이 그룹은 솔리드 작업 모형 그룹에 비해 소구치와 대구치에서 유의하게 높은 적합도 차이를 보였으며(P < 0.05), 특히 변연 및 교합 간격에서 유의하게 높은 편차를 보였다. 색상 편차 맵에서도 가철성 다이 그룹이 변연 및 교합 영역에서 더욱 높은 편차를 보였다. 결론: 3본 고정성 치과 보철물의 적합도 차이는 가철성 다이 시스템의 작업 모형 상에서 제작된 치과 보철물에서 초래되었으며, 이를 통해 가철성 다이 제작 방법이 치과 고정성 보철물의 정확성에 영향이 있었음을 검증하였다.

• 대한치과기공학회지
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• 제41권3호
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• pp.187-193
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• 2019

Purpose: The purpose of this study was to compare two-dimensional fitness of the monolithic zirconia prosthesis by using different type of scanner. Methods: No. 26 abutment tooth of FDI system was selected for the study. Using the extraoral scanner and intraoral scanner, the abutment tooth was scanned 10 times and the scanned files were saved as STL files. CAD/CAM system was used to produce the monolithic zirconia prosthesis. marginal and internal gap of the monolithic zirconia prosthesis were measured by digital microscope(x160) and applied silicone replica technique was applied. t-test, a statistical software, was used to perform data analysis. Results: Marginal gap $mean{\pm}SD$ of the monolithic zirconia prosthesis was $33{\pm}7.5{\mu}m$ with extra oral scanner and $34.7{\pm}11.1{\mu}m$ with intraoral scanner. axial gap mean was $40.5{\pm}3.5{\mu}m$ with extra oral scanner and $44.6{\pm}11.6{\mu}m$ with intraoral scanner. occlusal gap mean was $110.1{\pm}25.4{\mu}m$ with extra oral scanner and $64{\pm}9.7{\mu}m$ with intraoral scanner. Conclusion: In this study, fabricating zirconia prosthesis with different type of scanner was clinically applicable.

• The Journal of Advanced Prosthodontics
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• 제10권2호
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• pp.128-131
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• 2018

PURPOSE. This study aimed to evaluate the marginal discrepancy of full-arch frameworks in implant-supported prostheses fabricated using pre-sintered soft alloy (PSA). MATERIALS AND METHODS. Full-arch metal frameworks were fabricated on the edentulous implant model using casting alloy (CA), fully-sintered hard alloy (FHA), and PSA (n = 4 in each group). To evaluate the misfit of the framework to the abutments, the absolute marginal discrepancy (AMD) values of the frameworks were measured in cross-sectional images that had been drawn as part of the triple-scan protocol. The AMD values were compared among the tested alloy groups using the Kruskal-Wallis test, with a post hoc Mann-Whitney U test (${\alpha}=.05$). RESULTS. The FHA and PSA groups showed lower marginal discrepancies than the CA group (P<.001). However, the FHA group did not differ significantly from the PSA group. CONCLUSION. Soft alloy milling is comparable to hard alloy milling, and it is more precise than casting in terms of the marginal fit of implant-supported, full-arch prostheses.

• 구강회복응용과학지
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• 제18권4호
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• pp.313-320
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• 2002

The purpose of the present study was to evaluate the marginal discrepancy and topography of artificial crown on teeth extracted due to severe periodontal disease. Twenty specimens were invested into metamethylacrylate resin and cutted into vertical slices along with the long axis of tooth. The selected marginal discrepancy between the outer edge of the crown and the finishing line of abutment was examined by stereo- microscope(Olympus, PM-VSP-3, Japan) at magnification of up to 10, and the topography of finishing margin on crown was observed by stereomicroscopeat magnification of up to $70{\times}$. The results were as follows. (1) The mean marginal discrepancy between extracted tooth and artificial crown were $50.82{\mu}m$. (2) There was a considerable difference in the microstructure of finishing margins among specimens. Microscopic Structure on finishing margin showed indefinite line, poor fit (open, underextended and overextended), distorted margin, and surface roughness. This study suggested that there could be necessary to consider the response of periodontium to the emergence profile of natural tooth and precision of marginal geometry while establishing treatment planning for the reconsruction of the artificial crown.

• 대한치과보철학회지
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• 제49권2호
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• pp.145-151
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• 2011

연구 목적: 본 연구의 목적은 CAD/CAM과 MAD/MAM 시스템으로 제작된 3-unit 지르코니아 고정성 국소의치의 변연 적합도를 통상적인 방법으로 제작된 금속-도재 고정성 국소의치와 비교 분석하는 것이다. 연구 재료 및 방법: 레진 치아 (상악 중절치와 측절치)를 전부 도재관을 위한 형태로 삭제하고, 이를 인상 채득하여 에폭시 레진 모형을 제작하였다. 이 모형상에서 금속-도재 고정성 국소의치, CAD/CAM 지르코니아 고정성 국소의치 ($Everest^{(R)}$, Kavo Dental GmbH, Biberach, Germany), MAD/MAM 지르코니아 고정성 국소의치 ($Rainbow^{TM}$, Dentium Co. Inc., Seoul, South Korea)를각각5개씩 제작하였다. 제작된 고정성 국소의치를 레진 모형에 접착하고, 가공치 부위를 절단하여, 각각 광학 현미경 (Presize 440C)을이용, 145 배율로 변연 간격을 측정하였다. 측정된 결과는 one-way ANOVA test로 분석하였고, Duncan test로 사후 검정하였다 (${\alpha}$=.05). 결과: 각 군의 변연 간격의 평균과 표준편차는 금속-도재 고정성 국소의치 $78.48{\pm}11.05\;{\mu}m$, $Everest^{(R)}$ 시스템 $59.30{\pm}11.63\;{\mu}m$, $Rainbow^{TM}$ 시스템 $70.34{\pm}13.98\;{\mu}m$로 측정되었다. 결론: 1. $Everest^{(R)}$ 시스템이 금속-도재 고정성 국소의치보다 변연 간격이 작은 것으로 측정되었다 (P<.05). 2. $Everest^{(R)}$ 시스템과 $Rainbow^{TM}$ 시스템간의 변연 적합도는 유의성 있는 차이를 보이지 않았다 (P>.05). 3. $Rainbow^{TM}$ 시스템은 금속-도재 고정성 국소의치와 변연 간격에 유의 차가 없었다 (P>.05). 4. 각 군의 평균 변연 간격이 임상적으로 적합한 범위 내에 ($120\;{\mu}m$) 있었다.

• 한국콘텐츠학회논문지
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• 제16권1호
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• pp.151-157
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• 2016

구강인기방법과 지르코니아 블록 종류에 따른 지르코니아 코핑의 변연적합도 변화를 관찰하기 위해 2종의 고무인상재와 1종의 구강스캐너를 사용한 구강인기방법과 3종의 지르코니아 블록을 사용하여 지르코니아 코핑을 10개씩 제작하여 표면 거칠기와 변연적합도를 측정하였다. 표면 거칠기는 LUXEN Smile($2.3{\pm}0.9{\mu}m$) 블록이 가장 우수하였다. 그리고 협측 변연간격은 HL시편($26.5{\pm}2.1{\mu}m$), 설측 변연간격은 HL시편($27.2{\pm}2.1{\mu}m$), 근심 변연간격은 HJ시편($29.6{\pm}4.0{\mu}m$), 원심 변연간격은 HJ시편($29.0{\pm}3.0{\mu}m$)이 가장 낮게 나타났으며, 통계학적으로 유의차가 있었다(p<0.05). 이 결과, 구강인기방법과 지르코니아 블록 종류가 변연적합도에 영향을 준 것으로 나타났으며, 변연간격은 모든 군에서 임상적 허용 범위 내에 속했다.

• The Journal of Advanced Prosthodontics
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• 제11권5호
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• pp.262-270
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• 2019

PURPOSE. The purpose of this in vitro study was to evaluate the marginal misfits of three-unit frameworks fabricated with conventional and digital impressions techniques. MATERIALS AND METHODS. Thirty brass canine and second premolar abutment preparations were fabricated by using a computer numerical control machine and were randomly divided into 3 groups (n=10) as follows: conventional impression group (Group Ci), Cerec Omnicam (Group Cdi), and 3shape TRIOS-3 (Group Tdi) digital impression groups. The laser-sintered metal frameworks were designed and fabricated with conventional and digital impressions. The marginal adaptation was assessed with a stereomicroscope at ${\times}30$ magnification. The data were analyzed with 1-way analysis of variances (ANOVAs) and the independent simple t tests. RESULTS. A statistically significant difference was found between the frameworks fabricated by conventional methods and those fabricated by digital impression methods. Multiple comparison results revealed that the frameworks in Group Ci (average, $98.8{\pm}16.43{\mu}m$; canine, $93.59{\pm}16.82{\mu}m$; premolar, $104.10{\pm}15.02{\mu}m$) had larger marginal misfit values than those in Group Cdi (average, $63.78{\pm}14.05{\mu}m$; canine, $62.73{\pm}13.71{\mu}m$; premolar, $64.84{\pm}15.06{\mu}m$) and Group Tdi (average, $65.14{\pm}18.05{\mu}m$; canine, $70.64{\pm}19.02{\mu}m$; premolar, $59.64{\pm}16.10{\mu}m$) (P=.000 for average; P=.001 for canine; P<.001 for premolar). No statistical difference was found between the marginal misfits of canine and premolar abutment teeth within the same groups (P>.05). CONCLUSION. The three-unit frameworks fabricated with digital impression techniques showed better marginal fit compared to conventional impression techniques. All marginal misfit values were clinically acceptable.

• The Journal of Advanced Prosthodontics
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• 제12권3호
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• pp.167-172
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• 2020

PURPOSE. The aim of the present study was to investigate the passive fit of metal substructure after repetitive firing processes in implant-supposed prosthesis. MATERIALS AND METHODS. Five implants (4 mm diameter and 10 mm length) were placed into the resin-based mandibular model and 1-piece of screw-retained metal substructure was produced with the direct metal laser sintering (DMSL) method using Co-Cr compound (n = 10). The distance between the marked points on the multiunit supports and the marginal end of the substructure was measured using a scanning electron microscope (SEM) at each stage (metal, opaque, dentin, and glaze). 15 measurements were taken from each prosthesis, and 150 measurements from 10 samples were obtained. In total, 600 measurements were carried out at 4 stages. One-way ANOVA test was used for statistical evaluation of the data. RESULTS. When the obtained marginal range values were examined, differences between groups were found to be statistically significant (P<.001). The lowest values were found in the metal stage (172.4 ± 76.5 ㎛) and the highest values (238.03 ± 118.92 ㎛) were determined after glaze application. When the interval values for groups are compared with pairs, the differences between metal with dentin, metal with glaze, opaque with dentin, opaque with glaze, and dentin with glaze were found to be significant (P<.05), whereas the difference between opaque with metal was found to be insignificant (P=.992). CONCLUSION. Passive fit of 1-piece designed implant-retained fixed prosthesis that is supported by multiple implants is negatively affected by repetitive firing processes.

• 한국식생활문화학회지
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• 제22권6호
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• pp.794-800
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• 2007

The purpose of this study was to measure the tourists' preference for alternative restaurants with different combinations of 4 attribute levels: origin description, food type, price and service guarantee. A total of 210 questionnaires were completed from tourists who visited Kwangyang, Suncheon and Yeosu during Jan. 2 - Jan. 15, 2007. Conjoint experiment method was used to develop hypothetical restaurants. Ordinal probit model was used to measure the effects of attribute levels on the tourists' preference. Results of the study demonstrated that the ordinal probit model analysis result for the data indicated excellent model fit. The effects of attribute levels (origin description, traditional food, fusion food, price, service guarantee) on the tourists' preference were statistically significant. As expected, estimates of marginal willingness to pay for origin description(3.063), food type(2.349), and service guarantee(2.356) were statistically significant. Moreover, tourists were more willing to pay for origin description than other attribute levels. Tourists also considered the origin description as the very important attribute. In conclusion, based on conjoint analysis, a model was proposed of marginal willingness to pay of attribute levels. It should be noted that the original model was modified and should, preferably, be validated in future research.

• 대한치과기공학회지
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• 제36권2호
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• pp.75-81
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• 2014

Purpose: This study was to compare adaptations of lithium disilicate CAD/CAM crowns fabricated with different scanning systems. Methods: This study selected the mandibular right first molar as an abutment for experiments and produced 10 working models. Lithium disilicate crowns appropriate for each abutment were produced by using a CEREC$^{(R)}$ CAD/CAM system. The independent t-test was then used to compare and analyze the data obtained from the two groups(${\alpha}$=0.05). Results: Mean(SD) adaptation were $86.93(22.82){\mu}m$ for the InS group, $88.42(26.77){\mu}m$ for the ExS group. They were no statistically significant differences between groups for adaptation(p>0.05). Conclusion: Within the limitations of this study, the results suggest that the accuracy of all investigated optical scanner were satisfactory for clinical use. Further assessment and improvement of the lithium disilicate ceramic for the fabrication of FPDs is evidently still required.