접착재의 종류에 따른 In-Ceram 도재관의 변연적합도와 파절강도에 관한 연구

임주환,Lim, Ju-Hwan 대한치과보철학회 1998 대한치과보철학회지 Vol.36 No.6

In-Ceram system is one of contemporary esthetic all ceramic restorations and has relatively high flexural strength. The purpose of this study was to evaluate the marginal fidelity according to type of resin cement and measuring position, and to evaluate fracture strength according to type of resin cement. In this study, twenty seven In-Ceram crowns were fabricated on the metal master die of prepared maxillary right central incisor and devided into three groups. All specimens were cemented with Panavia 21 (group PV), Super-bond (group SB) and Lute-it (group LI) on the metal master die. After cementation, specimens were measured marginal gap between the margin of the In-Ceram crown and the finishing line of metal master die by using a stereomicroscope (SZ-ST, Olympus, Japan). Marginal gaps were recorded at the labial, lingual, mesial and distal measuring points on the metal master die. For the mesurement of fracture strength, lingual surfaces of cemented specimens were loaded at a distance of 1mm from incisal edge by using the Autograph S-2000 (Shimadzu, Japan). The results of marginal fidelity and fracture strength were statistically analyzed with the SPSS version 8.0 programs. The results of this study were as follows: 1. In comparison of marginal fidelity according to the measuring points, there was no significant difference. 2. The marginal fidelity according to the type of resin cement was decreased in order of group $LI\;(63.75{\mu}m),\;SB\;(77.78{\mu}m),\;PV\;(86.53{\mu}m)$, and there was significant difference between group LI and PV (p<0.05). 3. The fracture strength according to the type of resin cement was showed descending order of group $LI\;(60.00kg/cm^2),\;SB\;(56.80kg/cm^2),\;PV\;(56.11kg/m^2)$, but there was no significant difference.

가철성 다이를 가진 작업모형에서 다우엘 핀의 종류에 따른 정확도에 관한 연구

임주환,Lim, Ju-Hwan 대한치과보철학회 1997 대한치과보철학회지 Vol.35 No.2

In this study, 4 types of dowel pin were used to fabricate removable dies using the Pindex system. The comparison of interabutment distances between before and after sawing were conducted in each type of dowel pin, and the horizontal discrepancies in the interabutment distance according to the abutment location and the type of dowel pin were comparatively analyzed. Abutments LM(left molar), LP(left premolar), A(anterior), RP(right premolar), and RM (right molar) were used for measurement. The interabutment distances were measured between each abutment : LM-LP, LM-A, LM-RP, and LM-RM. The slide scanned image of each model was magnified on the computer screen and the measurements were conducted using the meeting point of the cross on the occlusal surface of each abutment. The results were as follows : 1. In the comparison of interabutment distances between before and after sawing in each type of dowel pin, there was no significant difference in World dowel pin(double), Bi-pin(double), Maxcel dowel pin(single). In the World dowel pin(single) there was no significant difference between LM-LPs, but in the other measurements (LM-As, LM-RPs, and LM-RMs) there was significant difference between before and after sawing(p<0.05). 2. In comparison of horizontal discrepancies of the measurement according to the abutment location, there was significant difference between measurement LM-LP($0.27{\pm}0.19mm$) and the others : LM-A($0.46{\pm}0.20mm$), LM-RP($0.38{\pm}0.25mm$), LM-RM($0.45{\pm}0.22mm$) (p<0.05). 3. In comparison of horizontal discrepancies of the measurement according to the type of dowel, there was no significant difference between each dowel. As a result when fabricating a removable die using the previously mentioned 4 types of dowel pins, it is thought that the horizontal discrepancy increased in proportion to the interabutment span length and does not depend on the type of dowel pin.

무치하악 골유착 고정성 브릿지의 삼차원적 유한요소 응력 분석

임주환(Ju-Hwan Lim),조인호(In-Ho Cho) 대한턱관절교합학회 1995 구강회복응용과학지 Vol.11 No.2

접착성 보철물의 설계와 접착제의 종류 및 사용방법에 따른 접착인장강도의 비교연구

임주환(Ju Hwan Lim),조인호(In Ho Cho),이재현(Jae Hyun Lee) 대한턱관절교합학회 1988 구강회복응용과학지 Vol.5 No.1

하천공간 복원 기능의 중요요인 및 우선순위 분석 연구

임주환(Ju Hwan Lim),이희찬(Hee Chan Lee),김지성(Ji Sung Kim),김규호(Kyu Ho Kim),한상필(Sang Feel Han) 위기관리 이론과 실천 2015 Crisisonomy Vol.11 No.4

본 연구는 하천 및 홍수터 등 공간 복원 시 발생할 것으로 기대되는 하천의 기능과 각 기능의 하위요인을 도출하고, 해당 기능과 하위요인간의 상대적 중요도 및 우선순위를 하천 유형별로 파악하는 것을 목적으로 수행하였다. 접근방법으로 Delphi 기법과 계층적 의사결정방법(AHP)을 적용하였다. 분석을 위한 자료 수집을 위해 하천 전문가를 대상으로 2회의 설문조사를 실시하였다. 분석결과 하천 유형별 중요기능과 요인이 다른 것으로 나타났으며, 농지 및 산지하천의 경우 생태기능이, 도심하천의 경우 수질정화 및 친수기능이 상대적으로 중요한 것으로 분석되었다. 연구의 결과는 하천복원 사업을 진행함에 있어 효율적인 정책대안과 합리적인 방향성을 제시할 수 있는 유용한 근거자료가 되고, 하천공간 기능에 대한 후속연구의 참고자료로서 활용 가능하다. The objective of this study is to analyze priority and important factors of river functions expected to generate in terms of spatial, mainly in the river and floodplain, restoration. In order to meet the goal, this study examined factors represented in previous reference literatures. This study used Delphi technique and AHP. The expert survey was conducted twice to collect data for the analysis. The results show that important functions and factors are different with each land-use type around river. The ecological function of river is more important in rural areas. Otherwise, the water purification and waterfront function is more important in river across urban areas. The results could be a useful basis for policy alternative and direction in the river restoration and utilize reference of a follow-up study about the river spatial restoration.

잔류농약 분석을 위한 새로운 질량분석기의 스마트한 솔루션 소개

임주환 ( Ju Hwan Lim ) 한국환경농학회 2023 한국환경농학회 학술대회집 Vol.2023 No.0

안전한 먹거리를 위한 잔류농약분석은 식품산업에서 중요한 과제 중 하나입니다. 최근 식품의약품안전처 및 농산물품질관리원에서는 잔류농약분석방법에 대해 시험방법을 개정하였습니다. 또한, PLS 대응을 위해 동시다성분의 농약 성분들은 계속 증가할 수 있습니다. 따라서, 한국애질런트에서는 전처리(QuEChERS)부터 Gas Phase, Liquid Phase Chromatography & Mass System을 이용한 잔류농약 분석에 대한 실무검사자의 이해를 돕고 정확한 검사 결과를 도출하기 위해 solution을 지속적으로 개발하고 있습니다. 잔류농약 분석 과정 중 위양성(False positive)문제는 계속적으로 문제가 되고 있습니다. 이를 해결하기 위해 애질런트의 tMRM 기능을 활용하여 재분석(Re-injection) 없이 한 번의 분석결과로 이 문제를 해결할 수 있습니다. 또한, 동시다성분 잔류농약 분석 시 극성 농약성분의 Peak shape등 불안정으로 인하여 불확실성의 결과를 도출하게 됩니다. 이를 개선하기 위해 Auto-dilution 기능을 활용하여 Data quality를 개선시킬 수 있습니다.

Periotest를 이용한 상, 하악 각 부위의 골질 평가에 관한 연구

林柱煥(Ju-Hwan Lim),曺仁鎬(In-Ho Cho) 대한치과의사협회 1994 대한치과의사협회지 Vol.32 No.7

도재전장주조관에 사용되는 도재의 색안정성에 관한 연구

류소영,임주환,조인호,Ryu, So-Young,Lim, Ju-Hwan,Cho, In-Ho 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.1

Dental porcelain should have adequate strength and similar esthetics as natural teeth. Recently esthetics has become a high priority in clinical dentistry. Thus the evaluation of color stability of dental porcelain has become an important part in dental research. The purpose of this study was to evaluate the difference in color stability of 3 types of porcelain(Vintage, VMK 95, CERAMCO II). The porcelain were divided into groups by 2 types of treatment(glazing or non-glazing and thermocycling or non-thermocycling). The porcelain were dyed with methylene blue and distilled water, and then the color stability was evaluated with a spectrophotometer The results were as follows; 1. The color change of porcelain increased in the order of VMK 95, Vintage, CERAMCO II. But there was no significant difference. 2. The color change decreased in the glazing group compared to the non-glazing group(p<0.05). 3. The color change increased after thermocycling But there was no significant difference. 4. The color change according to dye method was significantly larger with methylene blue copared to distilled water(p<0.05).

수종의 치과용 탄성인재의 정확도에 관한 연구

최명수,임주환,조인호,Choi, Myoung-Soo,Lim, Ju-Hwan,Cho, In-Ho 대한치과보철학회 1996 대한치과보철학회지 Vol.34 No.4

The accuracy and dimensional stability of impression materials are one of the most important factors for successful prosthodontic treatment. The purpose of this study was to evaluate the accuracy of several dental elastomeric impression materials used widely and clinically : Impregum-$F^{(R)},\;Permlastic^{(R)},\;Silascon^{(R)},\;Perfect^{(R)},\;Xantopren^{(R)}$. There have been many studies to evaluate the accuracy of impression materials. But it has not been decided yet, which method was most suitable for the evaluation of the accuracy. In this study, two resin teeth, #15 & 25, were prepared with rounded shoulder margin and 90 degree cavosurface angle. For the polysulfide rubber and polyether, the custom tray was made at least 24 hours prior to impression taking. For the silicone rubber materials, putty/wash impression technique was applied in taking impressions. Marginal openings of the castings on the master dies and prepared resin teeth were measured under stereomicroscope. The results were statistically analyzed and compared between tested impression materials. The results were as follows ; 1. In the overall accuracy of impression materials, polyether was the most accurate one, followed by polysulfide, additional silicone and condensation silicone. 2. On the first model pouring, condensation silicone had the largest discrepancies and there was significant difference compared to the other impression materials. 3. Polysulfide had the least discrepancies in the first model pouring, but showed larger discrepancies in the immediate second pouring than the first pouring. 4. On the immediate second pouring, the discrepancy of polyether was shown to be the smallest, while the largest one was additional silicone. 5. Polyether and polysulfide rubber using custom impression trays showed superior accuracy to silicone rubber, putty/wash impression technique.

치과 임플랜트 지대나사의 풀림 현상에 관한 연구

강윤모,임주환,조인호,Kang, Yun-Mo,Lim, Ju-Hwan,Cho, In-Ho 대한치과보철학회 1996 대한치과보철학회지 Vol.34 No.1

Abutment screw loosening of dental implant is a major problem in the treatment of dental implant. The purpose of this study was to examine the effect on the prevention of screw loosening according to tightening method and using of washer. In the first experiment, using a implant fixture and precisely fabricated temporary cylinder, the loosening torque was measured by tightening the screw 5 times repeatedly. In the second experiment, the fabricated crown and implant fixture was tightened by the screw that is attatched washer and then the loosening torque was measured after loading it 1800, 12600 times under the force of 150N. The results were as follows. 1. The highest loosening torque appeared after tightening 3 times repeatedly(p<0.01). 2. When the washer was used, the loosening torque was increased significantly under the loading 1800 times(p<0.01), 3. When the washer was used, the loosening torque was increaed under the loading 12600 times, but it is statistically not significant(p<0.01). The first experiment results mean that 3 times repeated tightening screw is most effective clinically. The second results mean that washer is effective in prevention screw loosening, but the effect is decreased with increasing load.