(An) experimental study on tensile strength of solder joints from various casting alloys

치의학과/석사[한글] 수개의 치아결손시 보철적 치료방법으로 고정성 가공의치가 널리 이용되고 있으며, 가공의치의 각 부분은 납착에 의하여 연결되므로, 치과임상에서 사용되는 각종 금속간의 납착에 관한 연구는 매우 중요하다고 생각된다. 이제 저자는 주조용 합금간 납착부의 인장강도 측정과 현미경적 관찰을 위하여, 귀금속합금으로 주조용 금합금 제3형 (ADA, Sp, No.5), 준귀금속합금으로 JP92(Jensen co.) 및 비귀금속합금으로 Rexillium Ⅲ (Jeneric gold co.)를 이용하여, 납착간격을 0.13mm로 하고 650fine의 금납으로 납착을 행한 후, Instron Universal Test Machine으로 인장강도를 측정하고 금속현미경으로 관찰하여 다음과 같은 결론을 얻었다. 1. 귀금속, 준귀금속 및 비귀금속합금 상호간의 납착이 모두 가능하였다. 2. 동일합금간 납착의 경우, 귀금속과 준귀금속에서 각각 46.38kg/mm**2, 46.16kg/m**2로 비교적 높았으며, 비귀금속에서는 43.81kg/m**2로 나타났다. 3. 이종합금간 납착의 경우, 귀금속과 준귀금속간, 귀금속과 비귀금속간 및 준귀금속과 비귀금속간에는 각각 42.28kg/m**2, 43..68kg/m**2 및 43.98kg/m**2로 나타났으며 유의의 차는 없었다. 4. 귀금속합금간 및 준귀금속합금간 납착의 경우, 금납과 각 합금과의 경계는 비교적 뚜렷하였고, 금납의 확산 및 합금내 입자의 크기변화는 거의 없었다. 5. 비귀속합금간의 경우, 금납과 합금간의 경계는 불분명하였고, 금납의 확산을 나타냈으며, 합금내 입자크기의 증가와 금납내의 공포형성이 관찰되었다. [영문] Fixed partial prosthesis as prosthodontic treatment of partially edentulous patient is widely used. Each unit of fixed partial prosthesis is connected by soldering. Therefore, the study in soldering of various alloys used in dentistry is very important. This study was undertaken for tensile strength and microscopic findings of solder joints from various alloys. The precious alloy used in this study was casting gold alloy Type Ⅲ(ADA Sp. No.5), the semiprecious alloy was JP 92(Jensen co.) and the nonprecious alloy was Rexillium Ⅲ (Jeneric gold co.)The gap space for solder joint was 0.13mm, and all specimens were soldered with solder gold of 650 fine. The tensile strength was measured with Instron Universal Test Machine, and solder joints were observed with photomicroscope. The results were obtained as follows: 1. Soldering from various combinations of precious, semiprecious and nonprecious alloys were possible. 2. In case of soldering between the same tensile strength between precious alloys showed 46.38 kg/mm**2, and semiprciou alloys showed 46.16 kg/m**2, and these were the higher valued groups. Between nonprecious alloys showed 43.81 kg/m**2. 3. In case of soldering between dissimilar alloys tensile strength between precious and semiparcious alloy showed 42.28kg/m**2, precious and nonprecious alloy showed 43.68kg/m**2 and between semiprecious and nonprecious alloy showed 43.98 kg/m**2. But, there was no significant value staistically. 4. In case of soldering between precious alloys and between semiprecious alloys, the interface of solder gold and alloys were distinct. Diffusion of solder gold and change in grain size of alloys were insignificant. 5. In case of soldering between nonprecious alloys, the interface of solder gold and alloys were indistinct due to diffusion of solder gold. Increase in grain size of alloys and many porosities in solder gold were observed.restrictio

(The) Influence of balancing side occlusal interference on the masticatory muscle activity and condylar path

치의학과/박사[한글] 균형측 교합장애는 저작근의 활성도에 영향을 미쳐 저작계의 기능장애를 유발하는 원인으로 알려져 왔으나 이러한 이론에 대해서는 많은 논란과 이견이 있어왔다. 저자는 원광대학교 치과대학생 8명을 대상으로 하여 인위적인 균형측 교합장애를 부여한 후 저작근활성도와 과로에 관하여 연구한 결과 다음과 같은 결과를얻었다. 1. 교합장애 부여시 PRI 값은 부여 3일후 증가하였으며 2주후부터 감소되었다. 2. 3명의 피검자에게서 균형측 교합장애 부여 3 - 4일후 경미한 측두하악 장애의 증상이 관찰되었으나 1 - 2주후부터 증상의 완화를 보였다. 3. 균형측 교합장애 부여 1주후 4명의 피검자에서 교합장애 부여측으로 껌저작시 동측 측두근 전엽에서의 근활성도의 감소를 보였다. 4. 균형측 교합장애 부여3일후 3명의 피검자에서 교합장애 부여 반대측으로 껌저작시 동측 측두근 전엽의 근활성도의 증가를 보였다. 5. 균형측 교합장애는 측두근 전엽과 교근 및 악이복근의 근활성도에 현저한 영향을 주지는 않았다. THE INFLUENCE OF BALANCING SIDE OCCLUSAL INTERFERENCE ON THE MASTICATORY MUSCLE ACTIVITY AND CONDYLAR PATH Tai Ho Jin, D.D.S.,M.S.D. Department of Dental Science, The Graduate School, Yonsei University (Directed by Prof. Ho Yong Lee, D.D.S.,M.S.D.,Ph.D.) A new photosensitizer, CpD(Chlorophyll derivatives), previously reported as a promising agent for tumor therapy, was studied to determine its inhibitory effects on Gross leukemia virus(GLV), a mouse retrovirus which was isolated from the GLV producing TGV cell line, and the cytocidal effect on the GLV infected cells in vitro. Following the photodynamic treatment with CpD and red light, the viral inactivactivity of the virus itself and that in the cell-free culture supernatant of freshly GLV-infected secondary mouse embryo cells respectively. The cytocidal activity was measured by trpan blue exclusion test. Significant inhibition of GLV associated RT activity resulted from CpD treatment following the irradiation of light. The RT inhibition effect was immediate and the infectivity of these photodynamically treated GLV to mouse embryo cells was also significantly inhibited. However, the specific cytotoxicity for the GLV infected cells was not recognized. Thus it was tentatively concluded that CpD may be used as an effective antiretroviral agent. [영문] A new photosensitizer, CpD(Chlorophyll derivatives), previously reported as a promising agent for tumor therapy, was studied to determine its inhibitory effects on Gross leukemia virus(GLV), a mouse retrovirus which was isolated from the GLV producing TGV cell line, and the cytocidal effect on the GLV infected cells in vitro. Following the photodynamic treatment with CpD and red light, the viral inactivactivity of the virus itself and that in the cell-free culture supernatant of freshly GLV-infected secondary mouse embryo cells respectively. The cytocidal activity was measured by trpan blue exclusion test. Significant inhibition of GLV associated RT activity resulted from CpD treatment following the irradiation of light. The RT inhibition effect was immediate and the infectivity of these photodynamically treated GLV to mouse embryo cells was also significantly inhibited. However, the specific cytotoxicity for the GLV infected cells was not recognized. Thus it was tentatively concluded that CpD may be used as an effective antiretroviral agent.restrictio