• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.240-250
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• 1999

The purpose of this study was to evaluate the effect of different etching time on the shear bond strength and adaptibility of composite to enamel and dentin when used one-bottle adhesive Prime & Bond$^{TM}$ 2.0. The proximal and occlusal surfaces of 88 extracted human molars were ground to expose enamel(n=44) and dentin (=44) using diamond wheel saw. Teeth were randomly assigned to four test groups(n=11) and received the following treatments : Control group were conditioned with 36% phosphoric acid for 20 sec. according to the manufacturer's directions. Experimental 10 sec. group, 30 sec. group and 60 sec. group were conditioned with 36% phosphoric acid for 10 sec., 30 sec. and 60 sec., respectively. Teeth were rinsed and dried for 2 sec. Prime & Bond$^{TM}$ 2.0 were applied according to the manufacturer's directions and Spectrum$^{TM}$ TPH composite resins were bonded to enamel and dentin surfaces. All specimens were stored in distilled water for 24 hours. Eighty specimens were sheared in a Universal Testing Machine with a crosshead speed of 5mm/minute. One way ANOVA and LSD test were used for statistical analysis of the data. Failure modes of all specimens after shear bond strength test were examined and listed. Also, representive postfracture modes and eight specimens were examined under scanning electron microscope. The results of this study were as follows: 1. The shear bond strength to enamel was the highest value in 30 sec. group (20.68${\pm}$8.54MPa) and the lowest value in 10 sec. group (14.92${\pm}$6.07MPa), so there was significant difference of shear bond strength between two groups (p<0.05). But there was no significant difference among other groups (p>0.05). With longer etching time to enamel from 10 sec. to 30 sec., higher the shear bond strength was obtained, but the shear bond strength was decreased at 60 sec. etching time. 2. The shear bond strength to dentin was the highest value in control group (13.08${\pm}$6.25MPa) and the lowest value in 60 sec. group (9.47${\pm}$3.35MPa), but there was no significant difference among the all groups (p>0.05). The eching time over 20 sec. decreased the shear bond strength to dentin. 3. In SEM observation, the enamel and resin interfaces were showed close adaptation with no relation to etching time of enamel. And the dentin and resin interfaces were showed close adaptation at 20 sec. and 30 sec. etching time, but showed some gaps at 10 sec. and 60 sec. etching time. Accordingly, these results indicated that a appropriate etching time in Prime & Bond$^{TM}$ 2.0 was required to be 30 sec. in enamel and 20 sec. in dentin for the high shear bond strength and good adaptation between the composite resin and tooth substance.

• 대한치과보철학회지
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• 제35권4호
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• pp.706-718
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• 1997

Ceramometal crowns are common restorations in fixed prosthodontics because of their casting accuracy, the high strength properties of the metal, and the cosmetic appearance of porcelain. However, deterioration of the initial fit of the metal coping has been observed after the porcelain firing cycle. The distortion due to repeated firing makes it difficult to fit crown margin and elicits microleakage. The major causes of distortion are the residual stress that accumulate during wax-up, casting, cold work and the induced stress caused by the mismatch of porcelain-metal thermal contraction. This study examined the marginal fit changes of metal copings in relation to repeated firing and the effects of heat treatment that reduce the distortion resulted from residual stress. The marginal changes of the copings that were treated with conventional method and those treated with heat before repeated firing, were evaluated. The metal die which represented preparations of a maxillary central incisor was fabricated, and 45 wax patterns were cast with nonprecious metal alloys. The heat treatment of each group was performed as follows. Group 1(control) : Casting - Devesting - Cold work - Firing Group 2 : Casting - Heat treatment - Devesting - Cold work - Firing Group 3 : Casting - Devesting - Cold work - Reinvesting - Heat treatment - Devesting - Firing The copings were fired 3 times. After each firing, the marginal fit changes were measured with inverted metallurgical microscope at the 4 reference points located at labial, lingual, and both proximal surface. Measurements were compared, and statistically analyzed. The results were as follows ; 1. In all groups, the highest value of marginal fit changes of the copings studied were found after the first firing cycle. 2. When the distortion of each experimental group at the first firing cycle were compared, group 1 exhibited the greatest changes($20-27{\mu}m$), followed by group 2($9-13{\mu}m$), and group 3($8-10{\mu}m$). 3. The copings treated with heat before devesting(group 2) revealed significantly smaller marginal fit changes than the copings treated with conventional method(group 1). (p<0.01) 4. The copings treated with heat after reinvesting(group 3) revealed significantly smaller marginal fit changes than the copings treated with conventional method(group 1). (p<0.01) 5. No siginificant differences in marginal fit changes were found between the copings treated with heat before devesting(group 2) and the copings treated with heat after reinvesting(group 3). (p>0.01)

• Journal of Chest Surgery
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• 제33권4호
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• pp.290-300
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• 2000

Background: To evaluate the diagnostic accuracy of EBT(Electron Beam Tomography) in the diagnosis of conotruncal anomaly and to determine whether it can be used as a substitute for cardiac angiography. Material and Method: 20 patients(11M & 9F) with TOF(n=7, pulmonary atresia 2), DORV(n=7), complete TGV(n=4), & corrected TGV(n=2) were included. The age ranged from 7 days to 26 years(median 60 days). We analyzed the sequential chamber localization, the main surgical concenrn in each disease category (PA size, LVED volume and coronary artery pattern for TOF & pulmonary atresia, the LV mass, LVOT obstruction, coronary artery pattern for complete TGV, and type of VSD and TV-PV distance for DORV, etc) and other associated anomalies(e.g., VSD, arch anomalies, tracheal stenosis, etc). Those were compared with the results of echocardiography(n=19), angiography (n=9), and surgery(n=11). The interval between EBT and echocardiography/angiography was within 20/11 days, respectively except for an angiography in a patient with corrected TGV (48 days). Result: EBT correctly diagnosed the basic components of conotruncal anomalies in all subjects, compared to echocardiography, angiography or surgery. These included the presence, type and size of VSD(n=20), pulmonic/LV outflow tract stenosis(n=15/2), relation of great arteries and the pattern of the proximal epicardial coronary arteries(16 out of 20). EBT proved to be accurate in quantitation of the intrapericardial and hilar pulmonary arterial dimension and showed high correlation and no difference compared with echocardiography, angiography, or surgery(p>0.05) except for left pulmonary arterial & ascending arterial dimension by echocardiography. LVED volume in seven TOF(no difference: p>0.05 & high correlation: r=0.996 with echocardiography), and LV mass in 4 complete TGV were obtained. Additionally, EBT enabled the cdiagnosis of subjlottic tracheal stenosis and tracheal bronchus in 1 respectively. Some peripheral PA stenosis were not detected by echocardiography, while echocardiography appeared to be slightly more accurate than EBT in detecing ASD or PDA. Conclusion: EBT can be a non-invasive and accurate modality of for the evaluation of most anatomical alteration including peripheral PS or interruption in patients with conotruncal anomalies. Combined with echocardiography, EBT study provides sufficient information for the palliative or total repair of anomalies.

• Clinics in Shoulder and Elbow
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• 제19권3호
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• pp.125-129
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• 2016

Background: Superior migration of humeral head has been conventionally determined by measuring the acromiohumeral distance (AHD), We sought to devise a novel measurement system more reliably and accurately than AHD. We described a structural landmark called 'C-line'. In this study, we investigated the clinical usefulness of 'step-off of the C-line (SOC)' compared to that of AHD. Methods: The C-line formed from the medial margin of the proximal humeral head continuing up to the inferior margin of the articular glenoid and then to the lateral border of the scapula. The superior migration of the humeral head triggered by a rotator cuff tear introduces a discontinuity in this C-line. We measured the distance of this discontinuity. We enrolled 144 patients who underwent a rotator cuff repair. We selected 58 controls who didn't have any cuff lesions apparent on magnetic resonance imaging. Using radiographs derived from standardized true anteroposterior views of the shoulder, we measured the SOC and the AHD. We used t-tests for statistical analyses. Results: A rotator cuff tear was associated with an increase in SOC and a decrease in AHD. In control group, the mean SOC was $1.29{\pm}1.71mm$ and AHD was $9.71{\pm}2.65mm$. In cuff tear group, the mean SOC was $3.15{\pm}3.41mm$ and AHD was $8.28{\pm}1.76mm$. The mean SOCs of the patient group in relation to the mean SOC of the control group according to tear size, the SOCs of medium tear and lager groups showed statistically significant increase (p<0.05). Conclusions: The SOC may be a similarly effective to diagnose cuff tears of medium size and larger compared with AHD.

• Annals of Clinical Neurophysiology
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• 제18권1호
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• pp.1-6
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• 2016

Background: Moyamoya disease is characterized by a progressive stenosis or occlusion of the intracranial internal carotid artery and/or the proximal portion of the anterior cerebral artery and middle cerebral artery. Whether the onset time was childhood or adulthood, the bony carotid canal diameter might be different, but reflects the size of internal carotid artery passing through the bony carotid canal. In this study, we aimed to identify the relationship between bony carotid canal diameter and clinical manifestation. Methods: 146 consecutive patients diagnosed with moyamoya disease by brain imaging studies were included. We measured the diameter of a transverse portion of bony carotid canal on bone window of a brain computed tomography(CT) image. Patients were divided into two groups, ischemic or hemorrhagic stroke according to clinical manifestation. As a result, 115 patients were included. The Suzuki stage was used as criteria for disease progression. Results: Bony carotid canal diameter was $3.6{\pm}0.5$ (right) and $3.6{\pm}0.4$ (left) in the hemorrhagic stroke group, and $3.7{\pm}0.4$ (right) and $3.6{\pm}0.4$ (left) in the ischemic stroke group. The bony carotid canal diameter of the moyamoya vessels (3.6 mm) was smaller than the diameter of non-moyamoya vessels (3.8 mm), significantly (p = 0.042). However, there was no difference in the collateral patterns and clinical manifestation in a comparison of both groups. Conclusions: In our study, there was no significant difference of clinical manifestations and collateral patterns depend on the bony carotid canal diameter in patients with moyamoya disease. These findings suggest that the clinical presentations of moyamoya disease are not related to the onset time of the disease.

• 대한정형외과 초음파학회지
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• 제7권1호
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• pp.28-32
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• 2014

목적: 슬관절 이하 부위의 정형외과적 수술을 위해 좌골 신경 차단 술기가 흔히 시행되고 있다. 좌골 신경 분지는 해부학적 차이가 있어 통상적인 신경 차단은 불완전한 신경 차단을 유발한다. 본 연구는 마취의 성공율을 개선하기 위하여 한국 여성에서 좌골 신경 분지 위치를 초음파를 이용해 확인하였다. 대상 및 방법: 한국 여성 33명을 대상으로 하였으며 체중, 키를 측정하였다. 초음파 측정을 위해 M-Turbo ultrasound system (SonoSite,Bothell, WA,USA) 13-6 MHz, 38 mm high frequency linear array transducer를 사용하였다. 복와위 자세에서 슬와 주름부터 분지부까지의 거리, 분지부에서 피부부터 신경까지의 깊이를 cm 단위로 측정하여 체중과 키와의 상관관계를 확인하였다. 측정은 한 명의 전문의에 의해 측정되었다. 통계는 SAS version 9.3를 사용하여 multiple linear regression 방법으로 분석하였다. 결과: 33명 여성의 평균 나이는 53세(34~71세), 평균 체중 59.7(50~77.1 kg), 평균 키 157.4(145~173.9 cm), 평균 BMI 24.1(18.4-28.9)였다. 슬와 주름에서 좌골 신경 분지부까지의 평균 거리는 5.7(4.5~7.5 cm)이였으며, 분지부에서 피부부터 신경까지의 평균 깊이는 2.4(1.8~3.2 cm)였으며, 통계적 분석 결과에서 거리와 키 조사 p-value 0.55, 거리와 몸무게 조사 p-value 0.34, 깊이와 키 조사 p-value 0.5, 깊이와 몸무게 조사 p-value 0.036 이였다. 결론: 한국 여성의 좌골 신경 분지 위치는 차이가 있었으며, 특히 몸무게에 따른 깊이 변화는 의미가 있었다. 한국 여성에서 좌골 신경 차단 술기를 시행할 때 평균 거리, 깊이를 생각하고 몸무게를 고려한다면 성공율이 증가할 것으로 생각되며, 슬와 주름 7.5 cm 상방에서 시행할 것을 추천하다.

• 한국어병학회지
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• 제8권1호
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• pp.57-67
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• 1995

평균 전장 $6.1{\pm}0.5cm$ 의 양식산 넙치, Paralichthys olivaceus 치어에 대한 포르말린의 1시간 2 시간, 4 시간 및 24 시간 급성독성 효과를 조사한 결과, 각 처리구간의 대조군은 모두 생존하였으며 포르말린에 대한 1 시간 $LC_{50}$ 값은 2,520 ppm 이며 95% 신뢰한계의 상한치는 2,540 ppm, 하한치는 2,490 ppm 이었다. 2 시간 $LC_{50}$ 값은 1,610 ppm 이며 95% 신뢰한계의 상한치는 1,630 ppm, 하한치는 1,590 ppm 이었다. 4 시간 $LC_{50}$ 값은 868 ppm 이며 95% 신뢰한계의 상한치는 885 ppm, 하한치는 851 ppm 이었다. 그리고 24 시간 $LC_{50}$ 값은 141 ppm 이며 95% 신뢰한계의 상한치는 147 ppm, 하한치는 136 ppm 이었다. 각 처리시간에서 독성실험 종료 후 죽은 개체들은 아가미덮개 및 입이 열리고 몸통이 유안측으로 만곡되었고 표피 점액질에 손상을 입은 독성증후를 나타내었다. 포르말린에 대한 24 시간 급성독성 실험 후 죽은 개체들의 아가미, 신장, 간 및 심장 조직을 대조군과 조직학적 비교를 한 결과 대조군은 모두 정상이었으나 24 시간 급성독성 실험군에서는 아가미세엽 (혈관 확장, 점액세포 파괴, 상피세포의 확장 및 괴사를 동반하는 퇴행성 병변), 신장 (쇄뇨관 상피세포 확장, 괴사 및 초자적의 퇴행), 간 (염색질의 핵막침착, 핵크기 감소 및 부분 혹은 전반적인 괴사) 및 심장 (핵의축, 심장근 확장 및 괴사) 조직에서 손상 등을 확인할 수 있었다. 현재 넙치의 세균성, 기생충성 질병의 구제에 포르말린 약욕이 실시되고 있어 해당 약제에 대한 넙치 치어의 독성실험 결과는 포르말린의 그 정확한 처리시간 및 처리농도를 결정하는데 중요한 자료로 판단된다.

• Journal of Korean Neurosurgical Society
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• 제30권sup2호
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• pp.281-288
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• 2001

Objectives : The purpose of this study is to evaluate the usefulness of SSEP monitoring during intracranial aneurysm surgery and compare the characteristics of wave change in relation to neurologic changes between ACA aneurysms and MCA aneurysms. Methods : During recent three years(between January 1997 and November 1999), intraoperative SSEP monitoring had been done in 63 operations for intracranial aneurysms. We had monitored the median nerve SSEP during surgery for aneurysms of MCA and the posterior tibial nerve SSEP for aneurysms of ACoA or ACA. A more than 50% reduction of any cortical SEP response was considered to be a significant SEP change, compared to its baseline value before the start of surgery. Changes in the SEPs were categorized as follows : Type IA, no significant amplitude changes without temporary clipping ; Type IB, no significant amplitude changes with temporary clipping ; Type II, significant changes with temporary clipping and complete return to control amplitude ; Type III, significant changes with temporary clipping and incomplete return to control amplitude ; Type IV, significant changes with temporary clipping and more decreased amplitude changes. Results : Among the 63 intraoperative monitoring, there were 37 cases of ACA aneurysms(An), and 26 of MCA An. The temporary proximal arterial occlusion during surgery were performed in 31(83.8%)cases of ACA An, 22(84.6%) of MCA An. Seven of the 31 ACA An(22.6%) and ten of the 22 MCA An(45.5%) had significant changes. The type were as follows : 4 patients with type II and 3 with type III in the ACA An ; 3 patients with type II and 3 with type III and 4 with type IV in the MCA An. In both group type II changes had no new postoperative neurological deficit. All 6 patients with type III had new neurological deficits ; However, One case in the ACA An and two cases in the MCA An. had transient neurologic deficit and improved markedly over the next two months. All 4 type IV changes in the MCA An. had permanant neurologic deficits. Two out of 30 cases(6.7%) in the ACA An. and one out of 16 cases(6.3%) in the MCA An. without significant amplitude change had new neurologic deficit postoperatively. Conclusion : Based on this study, Intraoperative SSEP monitoring during aneurysm surgery would provide useful information for detecting cerebral ischemia. SSEP response during surgery for MCA An. is more sensitive than ACA An. Otherwise, there were no meaningful difference in rate of false negativity.

• Journal of Yeungnam Medical Science
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• 제13권1호
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• pp.116-133
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• 1996

생체합금의 생체적합성을 검증하기위해, 표면처리가 되지 않은 타이타늄 봉과 표면처리를 시행한 타이타늄 봉을 실험용토끼의 대퇴골 근위부에 삽입하여 6주, 12주 및 26주후 방사선 관찰 후 광학현미경적 검사를 통한 골 반응을 비교 관찰하였다. 전 례에서 부식에 의한 반응은 관찰되지 않았으며, 신생골의 증식은 타이타늄의 삽입 후 26주까지 경도의 골증식이 관찰되었으나, 표면처리여부에는 관계가 없었다. 표면처리를 시행하지 않은 타이타늄의 삽입한 11례 중 1례의 경우 삽입 후 12주에 경도의 골괴사반응이 관찰되었으며 표면처리를 시행한 타이타늄을 삽입한 후 전 례에서 골괴사가 관찰되지 않았다. 이는 수술적 조작에 의한 것으로 사료되었다. 섬유원세포의 증식은 시기에 관계없이 전 례에서 관찰되었으며, 표면처리 여부 혹은 시간의 경과 정도와 관계가 없었다. 표면처리를 시행하지 않은 타이타늄의 삽입 후 6주에는 침윤정도 및 조직반응정도는 표면처리한 타이타늄의 삽입에 비해 통계적으로 유의하게 증가하였다. 그러나, 12주 및 26주 후에는 유의한 차이가 없었다. 다중회귀분석법의 단계별 투입방식을 이용하여 세포의 침윤율을 시간의 경과와 표면 처리여부에 따라 상관관계를 분석한결과, 세포 침윤율은 시간의 경과 및 표면처리를 하게 됨에 따라 감소하는 경향이 있었다. 조직 반응율의 정도도 침윤율과 유사한 양상을 나타내었다. 이상의 결과, 생체합금의 표면처리에 따라 골반응의 정도가 유의한 차이가 있었으므로 내고정 기구의 제작을 위해서는 보다 생체 적합성이 양호한 제작방법의 개발이 요구될 것으로 사료되었다.

• 자원환경지질
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• 제48권1호
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• pp.15-24
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• 2015

인도네시아 동부 자바의 남서익부에 위치하는 파찌딴 광화대 금속광화작용은 스카른형 교대광체와 열극을 충진 발달하는 열수 맥상광체로 크게 분류할 수 있다. 스카른 형 교대광체는 올리고신 후기 퇴적암류 중 석회암층을 따라 관계화성암체인 석영반암 주변에 발달한다. 본 광체는 스카른광물과 함께 자철석 및 천금속 황화광물이 수반된다. 열수광체로는 관계화성암체인 석영반암으로 부터의 거리를 기준으로 근지성 함 동-아연 망상광체와 원지성 함 연-아연(-금) 맥상광체가 발달 분포한다. 황화광물의 황 동위원소 값으로부터 계산된 $H_2S$의 황 동위원소 값은 스카른광체의 경우 5.6-7.1‰, 열수광체의 경우 0.9-6.8‰ 이었다. 이는 원지성 열수 맥상 광체의 후기 광화작용으로 진행하면서 파찌딴 열수계 내 $SO_4/H_2S$의 비가 증가하면서 $H_2S$의 황동위원소 값이 감소한 것으로 확인된다. 광화대 내 산소 동위원소 값은 스카른 광체 내 자철석, 9.6과 9.7‰; 스카른 광체 내 석영, 6.3-9.6‰; 스카른 광체 내 방해석, 4.7 and 5.8‰; 열수 망상광체 내 석영, 3.0-7.7‰; 열수 망상광체 내 방해석, 1.2 and 2.0‰; 열수 맥상광체 내 석영, -3.9 - 6.7‰로서, 계산된 ${\delta}^{18}O_{water}$ 값은 근지성 스카른 및 열수 망상광체에서 원지성 열수 맥상광체에 이르면서 감소하는 경향성을 보인다. 열수계 ${\delta}D_{water}$ 값은 광체 유형에 관계없이 -65 to -88‰의 값을 보여준다. 이러한 산소 수소 안정동위원소 값의 경향성은 근지성 스카른 및 열수 망상광체 초기 광화작용을 지배한 마그마 기원의 열수 또는 상대적으로 낮은 water/rock 비 값을 갖는 환경하에서 동위원소 교환반응을 이루어 평형상태에 이른 열수가 풍부한 파찌딴 열수계 내에 광화작용의 진행 및 관계화성암과의 거리에 따라 높은 water/rock 비 값을 갖는 환경하에서 동위원소 교환반응을 이루어 진 열수 또는 동위원소 교환반응이 거의 이루어지지 않은 천수의 유입이 점증하며 광화작용이 진행되었음을 의미 한다.