• Radiation Oncology Journal
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• v.16 no.4
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• pp.433-440
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• 1998

Purpose : Although small ceil lung cancer (SCLC) has high response rate to chemotherapy and radiotherapy (RT), the prognosis is dismal. The authors evaluated survival and failure patterns according to the prognostic factors in SCLC patients who had thoracic radiation therapy with chemotherapy. Materials and Methods : One hundred and twenty nine patients with SCLC had received thoracic radiation therapy from August 1985 to December 1990. Seventy-seven accessible patients were evaluated retrospectively among 87 patients who completed RT. Median follow-up period was 14 months (2-87months). Results : The two years survival rate was 13$\%$ with a median survival time of 14 months. The two year survival rates of limited disease and extensive disease were 20$\%$ and 8$\%$, respectively, with median survival time of 14 months and 9 months, respectively. Twenty two patients (88$\%$) of limited disease showed complete response (CR) and 3 patients (12$\%$) did partial response (PR). The two year survival rates on CR and PR groups were 24$\%$ and 0$\%$, with median survival times of 14 months and 5 months. respectively (p=0.005). No patients with serum sodium were lower than 135 mmol/L survived 2years and their median survival time was 7 months (p=0.002). Patients whose alkaline phophatase lower than 130 IU/L showed 26$\%$ of 2 year survival rate and showed median survival time of 14 months and those with alkaline phosphatase higher than 130 IU/L showed no 2 year survival and median survival time of 5 the months, respectively (p=0.019). No statistical differences were found according to the age, sex, and performance status. Among the patients with extensive disease, two rear survivals according to the metastatic sites were 14$\%$, 0$\%$, and 7$\%$ in brain, liver, and other metastatic sites, respectively, with median survival time of 9 months, 9 months, and 8 months, respectively (p>0.05). Two year survivals on CR group and PR group were 15$\%$ and 4$\%$, respectively, with a median survival time of 11 months and 7 months, respectively (p=0.01). Conclusion : For SCLC, complete response after chemoradiotherapy was the most significant prognostic tactor. To achieve this goal. there should be further investigation about hyperfractionation, dose escalation, and compatible chemo-radiation schedule such as concurrent chemo-radiation and early radiation therapy with chemotherapy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.783-794
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• 1994

Recently, several failure cases of concrete structures during construction have been reported. The main reason for these failures is attributed to the poor quality of concrete during construction. It is, therefore. necessary to develop and use high quality concrete. The purpose of the present study is to explore the characteristics of superplasticized concrete, especially the effects of mineral admixtures on the fluidity and strength characteristics of high performance concrete. The mineral admixtures considered in the present study are fly ash, blast furnace slag and silica fume, respectively. The major test variables include the amount of these mineral admixtures, cement contents and water-cement ratios. The compressive strengths for various cases were measured and reported. Optimum contents of mineral admixtures for strength development were derived. The corrosion phenomena of reinforcements embedded in various concrete specimens have been also studied. The present study provides useful basis to apply high-performance concrete to actual structures.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.133-141
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• 1993

From Jan.1982 to Dec.1990, 77 patients with rectal cancer were treated with curative surgical resection followed by postoperative adjuvant irradiation alone or combined with chemotherapy at the Department of Radiation Oncology, Korea University Hospital (KUH). Fifty-four (54/77, $70.1{\%}$) patients underwent abdominoperineal resection , 20 (20/77, $26{\%}$) patients underwent low anterior resection, and 3 (3/77, $3.9{\%}$,) patients had wide excision only. Thirty-nine (39/77, $50.5{\%}$) received sequential chemotherapy (2 cycles to 12 cycles). The 5-year survival rate for the entire group was $43{\%}:\;78.2{\%}$ in B2+B3, $39.4{\%}$ in stage C1+C2+C3. Survival rates decreased with increasing penetration of the bowel wall by tumor and the presence of regional lymph node metastasis. Those patients survival who underwent an abdominoperineal resection also experienced a significant decrease in compared to low anterior resection ($23.1{\%}$ vs. $63.8{\%}$ in 5-year survival, p <0.05). Local failure occurred in 15 ($19.5{\%}$) out of the 77 patients overall, 1($5.3{\%}$) of 19 in stage B2+B3, and 14 ($24.1{\%}$,) of 58 in stage C1+C2+C3. Presacral area was most common site of local failufre (8/17, $47.1{\%}$). Distant failure occurred in 13 ($16.9{\%}$) of 77 patients. The most frequent site of distant failure was the lung followed by the liver, the bone, and the brain. Combined locoregional and distant failure occurred in 2 ($2.6{\%}$) of 77 patients. Pathological confirmation of perirectal fat and/or regional lymph node involvement resulted in a singificant decrease in survival and local control.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.4
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• pp.284-291
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• 2013

Purpose: This study compared fracture strength and fracture modes between metal wire reinforcement and glass fiber reinforcement in repaired maxillary complete denture. Materials and methods: In this study, fracture was reproduced on center of maxillary complete dentures and the denture was repaired with auto-polymerizing resin. The experimental groups (n = 10) were subjected to the following condition: without reinforcing material (control group), reinforcing with metal wire (W group), reinforcing with glass fiber pre-impregnated with light-curing resin (SES MESH, INNO Dental Co., Yeoncheon, Korea, G group). The fracture strength and fracture modes of a maxillary complete denture were tested using Instron test machine (Instron Co., Canton, MA, USA) at a 5.0 mm/min crosshead speed. The flexure load was applied to center of denture with a 20 mm diameter ball attachment. When fracture occurred, the fracture mode was classified based on fracture lines. The Kruskal-wallis test and the Mann-whitney U test were performed to identify statistical differences at ${\alpha}=.05$. Results: W group showed the highest value of fracture strength, there was no significant difference (P>.05) between control group and G group. Control group and W group showed anteroposterior fracture mainly, group W showed adhesive fracture of denture base and reinforcing material. Conclusion: In limitation of this study, the glass fiber did not improve the fracture strength of repaired maxillary complete denture, and adhesive failure was occurred along the lines of glass fiber.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.17-23
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• 2002

Purpose : To clarify the clinical benefit derived from the combined modality therapy (CMT) consisting of chemotherapy (CT) and involved field radiotherapy (RT) for stage I and II angiocentric lymphomas of the head and neck. Materials and Methods : Of 143 patients with angiocentric lymphoma of the head and neck treated at our hospital between 1976 and 1995, 104 patients (RT group) received involved field RT alone with a median dose of 50.4 Gy (range : 20~70 Gy), while 39 patients (CMT group) received a median 3 cycles (range : 1~6 cycles) of CT before involved field RT. The response rate, patterns of failure, complications, and survival data of the RT group were compared with those of the CMT group. Results : Despite a higher response rate, local failure was the most common pattern of failure in patients of both groups. The patterns of failure, including the systemic relapse rate were not influenced by the addition of combination CT. Although both modalities were well tolerated by the majority of patients, aberrant immunologic disorders or medical illnesses, such as a hemophagocytic syndrome, sepsis, intractable hemorrhage, or the evolution of second primary malignancies were more frequently observed in patients of the CMT group. The prognosis of patients in the RT group was relatively poor, with a 5-year overall actuarial survival rate of 38% and disease-free survival rate of 32%, respectively. However, their clinical outcome was not altered by the addition of systemic CT. Achieving complete remission was the most important prognostic factor by univariate and multivariate analyses, but treatment modality was not found to be a prognostic variable influencing survival. Conclusions : Involved field RT alone for angiocentric lymphoma of the head and neck was insufficient to achieve an improved survival rate, but the addition of CT to involved field RT failed to demonstrate any therapeutic advantage over involved field RT alone.

• Radiation Oncology Journal
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• v.14 no.4
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• pp.291-297
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• 1996

Purpose : This study was performed to evaluate survival, failure patterns, and prognostic factors of MMR patients after radiation therapy. We also discussed the need for chemotherapy. Materials and Methods : A retrospective analysis was done for 23 patients with MMR who were treated with radiation therapy from June 1985 to November 1992. There were 19 male and 4 female patients, The patients' age ranged from 17 to 71 years (median 39 years). Systemic symptoms including fever, weight loss, or malaise were found in $30\%$ of the patients. The nasal cavity was most frequently involved No patients had nodal involvement at diagnosis. There were 2 patients with distant metastasis at presentation. Radiation therapy was delivered five times a week, 1.8 Gy daily, total $45\~54$ Gy (median 50.4 Gy) using 6 MV X-ray No patients received chemotherapy as initial treatment. Results : Overall 5-year and 10-year survival rates were $52.4\%$ and $44.1\%$, respectively. Seventy Percent(12/17) of the patients achieved complete response to radiotherapy, and $29.4\%$ (5/17) achieved partial response. The Patients with complete response showed a better 5-year survival rate than those with partial response ($66.9\%$ vs. $20\%$. p=0.004). Symptom duration before diagnosis, the presence of systemic symptom, and the number of primary sites had no influence on survival. The patterns of failure were as follows: local failure(1), failure in adjacent site(1), local and distant failure(1) distant metastasis(2). and conversion to malignant lymphoma(1). We could not find factors associated with the patterns of failure. Conclusion : The most important facto associated with survival was the response to radiotherapy. Seventeen percent of the patients had distant metastasis, and the salvage after distant metastasis was not successful. However. about $50\%$ of the patients could achieve long-term survival with local radiation therapy alone. Therefore, chemotherapy of MMR should be done after a prospective randomized study for the factors associated with distant metastasis.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.105-111
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• 1997

group($22\%\;vs.\;38\%$, p=0.24). The 5YSRs of 21 patients of primary tumor extension to adjacent sites and the other 13 patients of tonsillar proper site were $28\%\;and\;38\%$, respectively but the difference was not significant statistically(p=0.52) There was a statistically significant difference in 5YSRs between the groups of the Patients who received radiotherapy in less than 61days vs more than 60days($60\%\;vs.\;18\%$, p=0.027). All living Patients without any tumor progression(n=11) had suffered from serious late sequelae such as xerostomia, edentia, dental caries and one patient had the osteoradionecrosis of mandible. On univariate analysis. the duration of radiotherapy and T-stage were the significant prognostic factors affecting 5YSR. On multivariate analysis, also the duration of radiotherapy was the only significant Prognostic factor(p=0.01). Conclusion : There was no survival difference between the radiotherapy alone and with neoadiuvant chemothe groups. Although it was a retrospective study, the role of conventional radiotherapy alone could be effective as the local treatment modality only for the early stage of tonsillar carcinomas. But for the purpose of more improved survivals and better quality of lives of living patients, other altered fractionation such as hyperfractionated radiotherapy with shorter treatment time and smaller fraction size rather than conventional radiotherapy might be beneficial and these prospective studies are needed.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.2
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• pp.119-126
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• 2012

State of problem: Cement-retained implant-supported prostheses are routinely used in dentistry. The use of high strength cements has become more popular with the increasing confidence in the stability of the implant-abutment screw connection and the high survival rates of osseointegrated implants. No clinical data on retention of metal copings using CAD/CAM. To evaluate retention of metal copings using CAD/CAM system bonded to short titanium abutment with four different cements and compare retentive strength of metal copings with sandblasting or without sandblasting before cementation. Forty titanium abutment blocks were fabricated and divided into 4 groups of 10 samples each. Forty metal copings with occlusal hole to allow for retention testing were fabricated using CAD/CAM technology. The four cements were Fujicem(Fuji, Japan), Maxcem Elite(Kerr, USA), Panavia F2.0(Kurarary, Japan) and Superbond C&B(Sunmedical, Japan). The copings were cemented on the titanium abutment according to manufacture's recommendation. All samples were stored for 24h at 37oC in 100% humidity and tested for retention using universal testing machine(Instron) at a crosshead speed of 1.0mm/min. Force at retentive failure was recorded in Newton. The mode of failure was also recorded. Means and standard deviations of loads at failure were analyzed using ANOVA and Paired t-test. Statistical significance was set at P<0.05. Panavia F2.0 provided significantly higher retentive strength than Fujicem, Maxcem Elite(P<0.05). Sandblasting significantly increased bond strength(P<0.05). The mode of failure was cement remaining principally on metal copings. Within the limitation of this study, Panavia F2.0 showed significantly stronger retentive strength than Fujicem, Maxcem Elite(p<0.05). The Ranking order of the cements to retain the copings was Panavia F2.0, Fujicem = Maxcem Elite. Sandblasting significantly increased bond strength(P<0.05). The retentive strength of metal copings on implant abutment were influenced by surface roughness and type of cements.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.4
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• pp.359-370
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• 2011

To identify osseointegration of implants, dentists were performed the radiographic analysis. The fractal analysis methods using periapical radiographs before and after loading on implants was to evaluate whether or not significant. 30 patients who were placed implants in dental hospital of Wonkwang university were participated in this study. Total of 42 implants were analyzed. And, 14 males and 16 females aged from 22 to 73 participated in this study. The two morphologic and Fractal analysis of the one trabecular patterns in alveolar bone were done using periapical views. Two periapical views, after implant placement, and after 2 months of functional loading were analysed. The analysis was done by software, Image J(1.40s, National Institute of Health, Bethesda, USA). The data were statistically analyzed using one-way ANOVA(P<.05). Multiple comparison was done by the Tukey HSD test. The results of Fractal analysis and change in bone density around implants showed significantly different values, especially mandibles. However, in case of implants with failure, Fractal values decreased from 1.2865 to 1.1521 and 1.1135 to 1.0478.

• Journal of dental hygiene science
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• v.9 no.4
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• pp.405-412
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• 2009

The purpose of this study investigated the effect of Au coating on adhesion between porcelain matrix and metal substructure interface. Titanium, Ni-Cr alloy and Co-Cr alloy are well known as proper metal for the dental restorations. The success of a porcelain fused to metal (PFM) restoration depends upon the quality of the porcelain-metal bond. However, adhesion between dental alloys and porcelain is related to diffusion of oxygen during ceramic firing. The excessive oxidized layers make hard adhesion between dental alloy and ceramic. Ni-Cr and Co-Cr specimens were divided into test and a control group and Titanium specimens were divided into three test groups and a control group. Each group had 20 specimens. The adhesion characteristics of porcelain and metal with Au coating layer and without Au coating layer were observed with scanning electron microscopy(SEM). The adhesion was evaluated by a biaxial flexure test and volume fraction of adherent porcelain was determined by SEM/EDS analysis. Result of this study suggest that Au coating layer is effective barrier to diffuse oxide layer completely protect non-precious alloys from oxidation during the porcelain firing. The SEM photomicrographs of cross-section specimens showed a smooth interface between Au coating layer and metals and porcelain which suggested proper chemical bonding, and no gap, porosity were observed. The mode of failure was mainly adhesive for Ti tested specimens, but mixed failures with adhesive and cohesive were observed in Ni-Cr and Co-Cr specimens. The adhesion between non-precious metals and porcelain would not be improved by Au coating agent. However, It is suggested that the continuous study is required further investigation and development.