1.Effect of hydrofluoric acid-based etchant at an elevated temperature on the bond strength and surface topography of Y-TZP ceramics
Mi Kyung YU ; Myung Jin LIM ; Noo Ri NA ; Kwang Won LEE
Restorative Dentistry & Endodontics 2020;45(1):6-
OBJECTIVES: This study investigated the effects of a hydrofluoric acid (HA; solution of hydrogen fluoride [HF] in water)-based smart etching (SE) solution at an elevated temperature on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics in terms of bond strength and morphological changes.MATERIALS AND METHODS: Eighty sintered Y-TZP specimens were prepared for shear bond strength (SBS) testing. The bonding surface of the Y-TZP specimens was treated with 37% phosphoric acid etching at 20°C–25°C, 4% HA etching at 20°C–25°C, or HA-based SE at 70°C–80°C. In all groups, zirconia primers were applied to the bonding surface of Y-TZP. For each group, 2 types of resin cement (with or without methacryloyloxydecyl dihydrogen phosphate [MDP]) were used. SBS testing was performed. Topographic changes of the etched Y-TZP surface were analyzed using scanning electron microscopy and atomic force microscopy. The results were analyzed and compared using 2-way analysis of variance.RESULTS: Regardless of the type of resin cement, the highest bond strength was measured in the SE group, with significant differences compared to the other groups (p < 0.05). In all groups, MDP-containing resin cement yielded significantly higher bond strength values than MDP-free resin cement (p < 0.05). It was also shown that the Y-TZP surface was etched by the SE solution, causing a large change in the surface topography.CONCLUSIONS: Bond strength significantly improved when a heated HA-based SE solution was applied to the Y-TZP surface, and the etched Y-TZP surface was more irregular and had higher surface roughness.
Ceramics
;
Hot Temperature
;
Hydrofluoric Acid
;
Microscopy, Atomic Force
;
Microscopy, Electron, Scanning
;
Resin Cements
2.Effect of hydrofluoric acid-based etchant at an elevated temperature on the bond strength and surface topography of Y-TZP ceramics
Mi Kyung YU ; Myung Jin LIM ; Noo Ri NA ; Kwang Won LEE
Restorative Dentistry & Endodontics 2020;45(1):e6-
OBJECTIVES:
This study investigated the effects of a hydrofluoric acid (HA; solution of hydrogen fluoride [HF] in water)-based smart etching (SE) solution at an elevated temperature on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics in terms of bond strength and morphological changes.
MATERIALS AND METHODS:
Eighty sintered Y-TZP specimens were prepared for shear bond strength (SBS) testing. The bonding surface of the Y-TZP specimens was treated with 37% phosphoric acid etching at 20°C–25°C, 4% HA etching at 20°C–25°C, or HA-based SE at 70°C–80°C. In all groups, zirconia primers were applied to the bonding surface of Y-TZP. For each group, 2 types of resin cement (with or without methacryloyloxydecyl dihydrogen phosphate [MDP]) were used. SBS testing was performed. Topographic changes of the etched Y-TZP surface were analyzed using scanning electron microscopy and atomic force microscopy. The results were analyzed and compared using 2-way analysis of variance.
RESULTS:
Regardless of the type of resin cement, the highest bond strength was measured in the SE group, with significant differences compared to the other groups (p < 0.05). In all groups, MDP-containing resin cement yielded significantly higher bond strength values than MDP-free resin cement (p < 0.05). It was also shown that the Y-TZP surface was etched by the SE solution, causing a large change in the surface topography.
CONCLUSIONS
Bond strength significantly improved when a heated HA-based SE solution was applied to the Y-TZP surface, and the etched Y-TZP surface was more irregular and had higher surface roughness.
3.A Life-Threatening Bronchogenic Cyst
Sung Joon HAN ; Hyun Jin CHO ; Min Woong KANG ; Jae Hyeon YU ; Myung Hoon NA ; Shin Kwang KANG
The Korean Journal of Thoracic and Cardiovascular Surgery 2018;51(1):69-71
A bronchogenic cyst causing cardiac tamponade is a rare condition. We report an unusual case of a bronchogenic cyst that caused cardiac tamponade. A 49-year-old female patient presented at our emergency room with complaints of palpitations and shortness of breath that had lasted for 5 days preceding the visit. Echocardiography revealed a very large cystic mass compressing the left a trium posteriorly, and a large amount of pericardial effusion caused the diastolic collapse of the ventricles. Atrial fibrillation and aggravated dyspnea were observed, and the patient’s vital signs were unstable after admission. We therefore performed an emergency operation. The bronchogenic cyst was resected by thoracotomy and the patient was discharged 12 days after the operation without any complications over 5 years of follow-up.
Atrial Fibrillation
;
Bronchogenic Cyst
;
Cardiac Tamponade
;
Dyspnea
;
Echocardiography
;
Emergencies
;
Emergency Service, Hospital
;
Female
;
Follow-Up Studies
;
Humans
;
Middle Aged
;
Pericardial Effusion
;
Thoracotomy
;
Vital Signs
4.A Life-Threatening Bronchogenic Cyst
Sung Joon HAN ; Hyun Jin CHO ; Min Woong KANG ; Jae Hyeon YU ; Myung Hoon NA ; Shin Kwang KANG
The Korean Journal of Thoracic and Cardiovascular Surgery 2018;51(1):69-71
A bronchogenic cyst causing cardiac tamponade is a rare condition. We report an unusual case of a bronchogenic cyst that caused cardiac tamponade. A 49-year-old female patient presented at our emergency room with complaints of palpitations and shortness of breath that had lasted for 5 days preceding the visit. Echocardiography revealed a very large cystic mass compressing the left a trium posteriorly, and a large amount of pericardial effusion caused the diastolic collapse of the ventricles. Atrial fibrillation and aggravated dyspnea were observed, and the patient’s vital signs were unstable after admission. We therefore performed an emergency operation. The bronchogenic cyst was resected by thoracotomy and the patient was discharged 12 days after the operation without any complications over 5 years of follow-up.
5.In Vivo Neuroprotective Effect of Histidine-Tryptophan-Ketoglutarate Solution in an Ischemia/Reperfusion Spinal Cord Injury Animal Model.
Shin Kwang KANG ; Min Woong KANG ; Youn Ju RHEE ; Cuk Seong KIM ; Byeong Hwa JEON ; Sung Joon HAN ; Hyun Jin CHO ; Myung Hoon NA ; Jae Hyeon YU
The Korean Journal of Thoracic and Cardiovascular Surgery 2016;49(4):232-241
BACKGROUND: Paraplegia is a devastating complication following operations on the thoracoabdominal aorta. We investigated whether histidine-tryptophan-ketoglutarate (HTK) solution could reduce the extent of ischemia/reperfusion (IR) spinal cord injuries in a rat model using a direct delivery method. METHODS: Twenty-four Sprague-Dawley male rats were randomly divided into four groups. The sham group (n=6) underwent a sham operation, the IR group (n=6) underwent only an aortic occlusion, the saline infusion group (saline group, n=6) underwent an aortic occlusion and direct infusion of cold saline into the occluded aortic segment, and the HTK infusion group (HTK group, n=6) underwent an aortic occlusion and direct infusion of cold HTK solution into the occluded aortic segment. An IR spinal cord injury was induced by transabdominal clamping of the aorta distally to the left renal artery and proximally to the aortic bifurcation for 60 minutes. A neurological evaluation of locomotor function was performed using the modified Tarlov score after 48 hours of reperfusion. The spinal cord was harvested for histopathological and immunohistochemical examinations. RESULTS: The spinal cord IR model using direct drug delivery in rats was highly reproducible. The Tarlov score was 4.0 in the sham group, 1.17±0.75 in the IR group, 1.33±1.03 in the saline group, and 2.67±0.81 in the HTK group (p=0.04). The histopathological analysis of the HTK group showed reduced neuronal cell death. CONCLUSION: Direct infusion of cold HTK solution into the occluded aortic segment may reduce the extent of spinal cord injuries in an IR model in rats.
Animals
;
Aorta
;
Cell Death
;
Constriction
;
Humans
;
Male
;
Methods
;
Models, Animal
;
Neurons
;
Neuroprotective Agents*
;
Paraplegia
;
Rats
;
Rats, Sprague-Dawley
;
Renal Artery
;
Reperfusion
;
Reperfusion Injury
;
Spinal Cord Injuries*
;
Spinal Cord*
6.Outcomes of the Tower Crane Technique with a 15-mm Trocar in Primary Spontaneous Pneumothorax.
Yooyoung CHONG ; Hyun Jin CHO ; Shin Kwang KANG ; Myung Hoon NA ; Jae Hyeon YU ; Seung Pyung LIM ; Min Woong KANG
The Korean Journal of Thoracic and Cardiovascular Surgery 2016;49(2):80-84
BACKGROUND: Video-assisted thoracoscopic surgery (VATS) pulmonary wedge resection has emerged as the standard treatment for primary spontaneous pneumothorax. Recently, single-port VATS has been introduced and is now widely performed. This study aimed to evaluate the outcomes of the Tower crane technique as novel technique using a 15-mm trocar and anchoring suture in primary spontaneous pneumothorax. METHODS: Patients who underwent single-port VATS wedge resection in Chungnam National University Hospital from April 2012 to March 2014 were enrolled. The medical records of the enrolled patients were reviewed retrospectively. RESULTS: A total of 1,251 patients were diagnosed with pneumothorax during this period, 270 of whom underwent VATS wedge resection. Fifty-two of those operations were single-port VATS wedge resections for primary spontaneous pneumothorax performed by a single surgeon. The median age of the patients was 19.3±11.5 years old, and 43 of the patients were male. The median duration of chest tube drainage following the operation was 2.3±1.3 days, and mean postoperative hospital stay was 3.2±1.3 days. Prolonged air leakage for more than three days following the operation was observed in one patient. The mean duration of follow-up was 18.7±6.1 months, with a recurrence rate of 3.8%. CONCLUSION: The tower crane technique with a 15-mm trocar may be a promising treatment modality for patients presenting with primary spontaneous pneumothorax.
Chest Tubes
;
Chungcheongnam-do
;
Drainage
;
Follow-Up Studies
;
Humans
;
Length of Stay
;
Male
;
Medical Records
;
Pneumothorax*
;
Recurrence
;
Retrospective Studies
;
Surgical Instruments*
;
Sutures
;
Thoracic Surgery, Video-Assisted
7.Classic Peripheral Signs of Subacute Bacterial Endocarditis.
Yooyoung CHONG ; Sung Joon HAN ; Youn Ju RHEE ; Shin Kwang KANG ; Jae Hyeon YU ; Myung Hoon NA
The Korean Journal of Thoracic and Cardiovascular Surgery 2016;49(5):408-412
A 50-year-old female patient with visual disturbances was referred for further evaluation of a heart murmur. Fundoscopy revealed a Roth spot in both eyes. A physical examination showed peripheral signs of infective endocarditis, including Osler nodes, Janeway lesions, and splinter hemorrhages. Our preoperative diagnosis was subacute bacterial endocarditis with severe aortic regurgitation. The patient underwent aortic valve replacement and was treated with intravenous antibiotics for 6 weeks postoperatively. The patient made a remarkable recovery and was discharged without complications. We report this case of subacute endocarditis with all 4 classic peripheral signs in a patient who presented with visual disturbance.
Anti-Bacterial Agents
;
Aortic Valve
;
Aortic Valve Insufficiency
;
Diagnosis
;
Endocarditis
;
Endocarditis, Subacute Bacterial*
;
Female
;
Heart Murmurs
;
Hemorrhage
;
Humans
;
Middle Aged
;
Physical Examination
8.Simultaneous Manifestation of Gangliocytic Paraganglioma and Heterotopic Pancreas of Ampulla of Vater Treated by Endoscopic Resection.
Gyoun Eun KANG ; Hyunsoo KIM ; Jae Kwang LEE ; Dong Hyun KIM ; Bi Na JEONG ; Ji Hun JANG ; Sang Myung YEO ; Kyung Rak SOHN
Korean Journal of Pancreas and Biliary Tract 2016;21(4):232-238
Gangliocytic paraganglioma is an uncommon tumor of digestive system that is usually found in the second portion of duodenum. It is generally considered benign tumor, although few reports of local recurrences and regional lymph node metastases have been made. Gangliocytic paraganglioma is characterized by its histologic pattern including ganglion cells, spindle cells and epithelioid cells. Heterotopic pancreas, also known as ectopic pancreas, is a pancreatic tissue appeared outside of its normal location lacking anatomic or vascular connection with the pancreas. In duodenum, it is a relatively unusual lesion that may be found incidentally during surgery or endoscopy. We present a case of 39-year-old woman with gangliocytic paraganglioma combined with heterotopic pancreas in the ampulla of Vater successfully treated by endoscopic resection.
Adult
;
Ampulla of Vater*
;
Digestive System
;
Duodenum
;
Endoscopy
;
Epithelioid Cells
;
Female
;
Ganglion Cysts
;
Humans
;
Lymph Nodes
;
Neoplasm Metastasis
;
Pancreas*
;
Paraganglioma*
;
Recurrence
9.Simultaneous Manifestation of Gangliocytic Paraganglioma and Heterotopic Pancreas of Ampulla of Vater Treated by Endoscopic Resection.
Gyoun Eun KANG ; Hyunsoo KIM ; Jae Kwang LEE ; Dong Hyun KIM ; Bi Na JEONG ; Ji Hun JANG ; Sang Myung YEO ; Kyung Rak SOHN
Korean Journal of Pancreas and Biliary Tract 2016;21(4):232-238
Gangliocytic paraganglioma is an uncommon tumor of digestive system that is usually found in the second portion of duodenum. It is generally considered benign tumor, although few reports of local recurrences and regional lymph node metastases have been made. Gangliocytic paraganglioma is characterized by its histologic pattern including ganglion cells, spindle cells and epithelioid cells. Heterotopic pancreas, also known as ectopic pancreas, is a pancreatic tissue appeared outside of its normal location lacking anatomic or vascular connection with the pancreas. In duodenum, it is a relatively unusual lesion that may be found incidentally during surgery or endoscopy. We present a case of 39-year-old woman with gangliocytic paraganglioma combined with heterotopic pancreas in the ampulla of Vater successfully treated by endoscopic resection.
Adult
;
Ampulla of Vater*
;
Digestive System
;
Duodenum
;
Endoscopy
;
Epithelioid Cells
;
Female
;
Ganglion Cysts
;
Humans
;
Lymph Nodes
;
Neoplasm Metastasis
;
Pancreas*
;
Paraganglioma*
;
Recurrence
10.Pulmonary Artery Angiosarcoma Confused with Acute Pulmonary Thromboembolism: Focusing on Clinical and Echocardiographic Features in the Differentiation of Two Categories.
Mi Joo KIM ; Min Su KIM ; Jae Hyeong PARK ; Kwang In PARK ; Choong Sik LEE ; Myung Hoon NA ; Jae Hwan LEE ; Si Wan CHOI ; Jin Ok JEONG ; In Whan SEONG
Journal of Cardiovascular Ultrasound 2015;23(1):44-47
Although pulmonary artery angiosarcoma is rare, it can be misdiagnosed as pulmonary embolism because of its similar clinical and diagnostic features. The diagnosis is often delayed and the misdiagnosis brings unnecessary treatment. Because we made a wrong diagnosis of pulmonary artery angiosarcoma as an acute pulmonary embolism, we did thrombolytic therapy which could be dangerous to the patient. In this case report, we focused on the clinical and echocardiographic features of pulmonary artery angiosarcoma which can be used in differentiating the diagnosis from pulmonary embolism.
Diagnosis
;
Diagnostic Errors
;
Echocardiography*
;
Hemangiosarcoma*
;
Humans
;
Pulmonary Artery*
;
Pulmonary Embolism*
;
Thrombolytic Therapy

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