수종의 dentin bonding agent가 도채 라미네이트용 복합레진 시멘트의 전단결합 강도에 미치는 영향

권주홍,동진근,조혜원 원광대학교 치의학연구소 1992 圓光齒醫學 Vol.2 No.2

The purpose of this study was to evalute the influence of three dentin bonding agents on the shear bond strength of resin coments for porcelain laminate veneer. The three dentin bonding agents such as Scotchbond 2, All Bond 2, and Prisma universal bond 2 and the two resin cements such as G-Cera cement and Porcellite cement were used in this study. The specimens were stored in 37C, 100% humidity for 48 hours and shear bond strengths of resin cements to dentin and enamel were measured with Instron testing (model no. 4201) at crosshead speed of 1.0㎜/min. The results were as follows 1. The shear bond strength of resin cements for porcelain laminate veneer to dentin was enhanced with the use of dentin bonding agent. 2. The shear bond strength to dentin with All bond 2 was highest in the G-cera cement groups. 3. The bond strength of Procelite cement to dentin with Scotchbond 2 and All bond 2 were higher than that of Prisma universal bond 2 but there was no difference between Scotchbond 2 and All Bond 2. 4. The shear bond strength to enamel with All bond 2 was highest in the G-cera cement groups and dentin bonding agents did `nt show any effect bond strength of porcelite cement to enamel.

단일치 임플랜트 지지 보철물에서 고정체와 지대주 나사 직경의 차이에 따른 삼차원 유한요소법적 응력 분석

권주홍,최민호,김유리,조혜원,Kwon Joo-Hong,Choi Min-Ho,Kim Yu-Lee,Cho Hye-Won 대한치과보철학회 2005 대한치과보철학회지 Vol.43 No.1

Statement of problem. As the effects of the various diameters of fixture and abutment screw on stress distribution was not yet examined, this study focused on the different design of single implant restoration using three dimensional finite element analysis. Purpose. This study was to compare five different fixture-abutment combinations for single implant supported restorations with different fixture and abutment screw diameters. Material of methods. The five kinds of finite element models were designed by 3 diameter fixtures ($\oslash$3.3, 3.75, 5.0 mm) with 3 different abutment screws $\oslash$1.5, 1.7, 2.0 mm). The crown for mandibular first molar was made using UCLA abutment according to Wheeler's anatomy. 244 N was applied at the central fossa with two different loading directions, vertically and obliquely (30$^{\circ}$) and at the buccal cusp vertically. Maximum von Mises stresses were recorded and compared in the supporting bone, crowns, fixtures, and abutment screws. Results. 1. The stresses in supporting bone and implant-abutment structure under oblique loading were greater than those under vertical or offset loading. The stresses under vertical loading were the least among 3 loading conditions regardless of the implant and abutment screw diameters. 2. The stresses in the narrow implants were greater than the wider implants. The narrow implant with narrow abutment screw showed highest stresses in the lingual crest, but the narrow implant with standard abutment screw showed highest stress in abutment screw. 3. The stresses of abutment screws were influenced by the diameter of fixtures and loading conditions. The wide implants showed least difference between two different abutment screw diameters. Conclusions. The wide implants showed lesser stresses than the narrow implants and affected least by the different abutment screw diameters. The narrow implants with standard abutment screw showed highest stresses in the lingual bony crest under oblique loading.

강 유전체 박막을 위한 하부전극 MOCVD-pt 박막의 특성

권주홍,윤순길,Gwon, Ju-Hong,Yun, Sun-Gil 한국재료학회 1996 한국재료학회지 Vol.6 No.12

반도체 메모리 소자에 이용되는 하부전극의 Pt 박막을 MOCVD 증착방법을 이용하여 SiO2(100nm)/Si 기판위에 증착하였다. 반응개스로 O2개스를 사용하였을 경우에 순수한 Pt 박막을 얻었으며 증착층은(11)우선방향을 가지고 성장하였다. 증착온도가 45$0^{\circ}C$에서는 결정립 경계에 많은 hole이 형성되어 박막의 비저항을 증가시켰다. MOCVD에 의해 얻어진 Pt 박막은 전 증착온도범위에서 인장응력을 가지고 있었으며 40$0^{\circ}C$이상의 온도에서 hole이 형성되면서 응력은 감소하였다. MOCVD-Pt 위에 PEMOCVD로 증착한 강 유전체 SrBi2Ta2O9박막은 균일하고 치밀한 미세구조를 보였다.

단일치 임플란트 지지 보철물에서 고정체와 지대주 나사 직경의 차이에 따른 삼차원 유한요서법적 응력 분석

권주홍,조혜원 원광대학교 치의학연구소 2001 圓光齒醫學 Vol.10 No.2

With increasing demand of the implant-supported prosthesis, it is advantageous to use the fixtures of different diameters according to bone quantity and quality of the patients. The diameter of the abutment screw also can be used as the same diameter with that of the standard fixture or directly proportional to the fixture diameter. As the effects of the various diameters of fixture and abutment screw on stress distribution is not yet examined, this study is to focus on the different design of single implant restoration using three dimensional finite element analysis. The five kinds of finite element models were designed by 3 diameter fixtures ( 3.3, 3.75, 5.0㎜) with 3 different abutment screws ( 1.5, 1.7, 2.0㎜). The crown for mandibular first molar was made using UCLA abutment according to Wheeler's anatomy. 244 N was applied at the central fossa with two different loading direction, vertically and obliquely (30^。) and at the buccal cusp vertically. Maximum von Mises stresses were recorded and compared in the supporting bone, crowns, fixtures, and abutment screws. The results were as follows: (1) The minimum stress occured at the central fossa under vertical force and the difference from fixture or abutment screw in all elements such as supporting bone fixture crown a little. The maximum stress occured at the central fossa under oblique forces regardless of the diameter of fixture and abutment screw. (2) The stress amount about on the supporting bone was equally distributed at the cortical bone and cancellous bone regardless of the diameter of fixture when the vertical force is applied. The stress showed tendency to increase as the rate of five to ten times at the alveolar bone under oblique force, also it was increased when the diameter of fixture was small. (3) The stress amount of the small diameter fixture was more than the wide diameter fixture in fixture and crown , and it was not much influenced by the diameter of the abutment screw. The maximum stress value occured at the load point under vertical force, and it was occurred at crown-fixture interface under oblique force. (4) The stress amount of abutment screw was different by the diameter of the fixture. It was decreased when the diameter of fixture was wide and distibuted along the whole thread, also it decreased as the diameter of thread is smaller in 3.3mm fixture. It showed tendency to decreased the supporting bone and crown fixture when fixture diameter was increased. The wide diameter fixture were not much influenced by the abutment screw diameter. When the abutment screw was wide, the stress in the small diameter was increased. The wide diameter was more advantageous than the small diameter due to the little stress.

수종의 dentin bonding agent가 도재라미네이트용 레진시멘트의 전단 결합강도 및 변연 누출에 미치는 영향

박윤기,조혜원,권주홍 大韓齒科器材學會 1993 대한치과재료학회지 Vol.20 No.1

The purpose of this study was to evaluate the influence of three dentin bonding agents on the shear bond strength, microleakage, and film thickness of resin cement for porcelain laminate veneer. Dentin & enamel surfaces were treated with three dentin bonding agents such as Scotchbond 2. All Bone 2, and Prisma Universal Bold 2 and were cemented by G-Cera cement for porcelain laminate veneer. For bond strength test, the specimens were stored in 37℃, 100% humidity for 48 hours and shear bond strength was measured with Instron testing machine (model no. 4201) at crosshead speed of 1.0mm/min. For microleakage and film thickness measurement, the specimens were stored in 37℃, 100% humidity for 7 days, thermocycled for 1000 cycles. Microleakage and film thickness of resin cement were measured with inverted metallurgical microscope(PME 311, Olympus, Japan). The results were as follows : 1. The shear bond strength of resin cement for porcelain laminate veneer to dentin was enhanced by the use of dentin bonding agent and All Bond 2 were effective in improving the shear bond strength to both enamel and dentin. 2. All Bond 2 were effective in reducing microleakage of veneers bonded to dentin, approximately to the same degree to the veneers bonded to enamel. But Prisma Universal Bond 2 and Scotchbond 2 failed to limit microleakage at the gingival margin of veneers bonded to dentin. 3. the 40% phosphoric acid in G-Cera system and the 10% phosphoric acid in All Bond 2 appeard equally effective in reducing microleakage of veneers bonded to enamel. 4. There were no significant increase in cement film thickness when using Prisma Universal Bold 2 or Scotchbond 2, but with All Bond 2 slight increase in the cement film thickness were present.

Crowbar 장치를 이용한 최초 단시간뇌격전류 발생기술 및 뇌격전류발생기 개발

엄주홍(Ju-Hong Eom),이태형(Tae-Hyung Lee),권기량(Ki-Ryang Kwon),조성철(Sung-Chul Cho) 한국조명·전기설비학회 2011 조명·전기설비학회논문지 Vol.25 No.1

This paper presents a technical study for the first short stroke lightning current generator using a crowbar device. The so-called crowbar-technology is most common to make 10/350[㎲] impulse currents with high amplitude, and the lightning current generator with crowbar device has an economic advantage than the nominal RLC current generator. But both the operating efficiency and the operating reliability of crowbar spark gap are very important to design the current generator. So, the peaking circuit which consists of small capacitors and a spark gap is applied. And the multi-step coil for controlling the circuit constant at the different test conditions is used. The presented test facility is designed to perform impulse tests with amplitudes up to 50[㎄] of 10/350[㎲].

道路交通의 理論的解析

金周弘,權鎭東,金在功 동국대학교 1978 論文集 Vol.17 No.-

This research was purposed to study the basic traffic control by the method of on-line computer system in the problem of traffic lights at acrossing. As a method for the decision of control mode, the theoretical analysis about the traffic flow was attempted, and the traffic flow on Highway vehicles and their waiting time for the traffic signal in Seoul were measured and analized. With the result of above analysis, after compared with the traffic system of foreign countries, the on-line Computer Control System in Seoul was proposed.

스트레인 게이지를 이용한 임플랜트 지지 오버덴춰의 응력분석

조혜원,권주홍,이화영,Cho, Hye-Won,Kwon, Joo-Hong,Lee, Wha-Young 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.1

Stress distribution on mandibular implants supporting overdentures were registered in vitro experimental model by means of 4 rosette gauges which were placed around the implant. The overdenture attachments used in this study were the Resilient Dolder bar, Rigid Bolder bar, Round bar, Hader bar & Dal-Ro attachment. An occlusal jig was placed on the overdenture and the loading sites were 3 points which mimicked working, balancing, and median relations. With 5 and 10kg loading, strains were measured by strain indicator(P-3500, Measurement group, Raleigh, USA), and using these data, maximum and minimum principal stresses and Von Mises stress were calculated and evaluated. The results were as follows : There was a tendency of high stress concentration in the lingual side of the implant, and in the buccal side low stress was developed regardless of the attachment systems. The resilient Bolder bar concentrated highest stress among the attachment systems, and the Round bar and the Dal-Ro attachment provided comparatively low stresses around the implant. The rigid Bolder bar concentrated high stress in the mesial side, and the Dal-Ro attachment developed tensile stress patterns in the lingual and distal sides of the implant at the balancing relation.

금속표면처리제에 따른 코발트-크롬 합금과 의치상용 레진의 결합강도

박종일,권주홍,이해형,조혜원,Park, Jong-Il,Kwon, Ju-Hong,Lee, Hae-Hyeung,Cho, Hay-Won 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.2

This study evaluated the effects of four adhesive metal primers on the shear bond strength of a heat curing denture base resin(Lucitone 199) to cobalt-chromium alloy(Biosil-f). The adhesive metal primers were Cesead Opaque Primer, Metal Primer, MR Bond, and Super-Bond liquid. The metal surface primed or nonprimed was filled with the heat-curing methyl methacrylate resin. The specimens were stored in water at $37^{\circ}C$ for 24 hours and the alternately immersed in water bath at $5^{\circ}C\;and\;55^{\circ}C$ for up to 2,000 thermal cycles. Shear bond strengths were measured using UTM at a crosshead speed of 0.5mm/min. Failure surface were examined under magnifying glasses. All the primers examined improved the shear bond strength between denture base resin and cobalt-chromium alloy compared with nonprimed specimens before thermal cycling. The bond strength of Cesead Opaque Primer was greatest. And after 2,000 thermal cycles, the bond strengths between resin and cobalt-chromium alloy were decreased but the difference between thermal cycling 0 and 2,000 at Cesead Opaque primer and Metal Primer were not significant. This study indicated that Cesead Opaque Primer & Metal Primer is effective primers to obtain higher bond strength between heat cured denture base resin and cobalt-chromium alloy.

編輯後記

張公子,金啓東,權萬學,尹德敏,尹眞杓,李行,洪圭德,黃柱洪 한국국제정치학회 1993 國際政治論叢 Vol.32 No.2