OBJECTIVES: The purpose of this study was to evaluate the polymerization shrinkage stress among conventional methacrylate-based composite resins and a silorane-based composite resin. MATERIALS AND METHODS: The strain gauge method was used for the determination of polymerization shrinkage strain. Specimens were divided by 3 groups according to various composite materials. Filtek Z-250 (3M ESPE) and Filtek P-60 (3M ESPE) were used as a conventional methacrylate-based composites and Filtek P-90 (3M ESPE) was used as a silorane-based composites. Measurements were recorded at each 1 second for the total of 800 seconds including the periods of light application. The results of polymerization shrinkage stress were statistically analyzed using One way ANOVA and Tukey test (p = 0.05). RESULTS: The polymerization shrinkage stress of a silorane-based composite resin was lower than those of conventional methacrylate-based composite resins (p < 0.05). The shrinkage stress between methacrylate-based composite resin groups did not show significant difference (p > 0.05). CONCLUSIONS: Within the limitation of this study, silorane-based composites showed lower polymerization shrinkage stress than methacrylate-based composites. We need to investigate more into polymerization shrinkage stress with regard to elastic modulus of silorane-based composites for the precise result.
Composite Resins ; Elastic Modulus ; Light ; Polymerization ; Polymers ; Sprains and Strains

PURPOSE: . This study aimed to fabricate provisional crowns at varying build directions using the digital light processing (DLP)-based 3D printing and evaluate the marginal and internal fit of the provisional crowns using the silicone replica technique (SRT). MATERIALS AND METHODS. The prepared resin tooth was scanned and a single crown was designed using computer-aided design (CAD) software. Provisional crowns were printed usinga DLP-based 3D printer at 6 directions (120°, 135°, 150°, 180°, 210°, 225°) with 10 crowns in each direction. In total, sixty crowns were printed. To measure the marginal and internal fit, a silicone replica was fabricated and the thickness of the silicone impression material was measured using a digital microscope. Sixteen reference points were set and divided into the following 4 groups: marginal gap (MG), cervical gap (CG), axial gap (AG),and occlusal gap (OG). The measurements were statistically analyzed using one-way ANOVA and Dunnett T3. RESULTS: MG, CG, and OG were significantly different by build angle groups (P<.05). The MG and CG were significantly larger in the 120° group than in other groups. OG was the smallest in the 150° and 180° and the largest in the 120° and 135° groups. CONCLUSION The marginal and internal fit of the 3D-printed provisional crowns can vary depending on the build angle and the best fit was achieved with build angles of 150°and 180°

BACKGROUND: Methyl alcohol poisoning has been mainly reported in community. Two cases of methyl alcohol poisoning occurred in a small-sized subcontracted factory which manufactured smartphone parts in Korea. CASE PRESENTATION: One young female patient presented with dyspnea and visual disturbance. Another young male patient presented with visual disturbance and myalgia. They treated with sodium bicarbonate infusion and hemodialysis for metabolic acidosis. In addition, he received ethyl alcohol per oral treatment. Her and his urinary methyl alcohol concentration was detected as 7.632 mg/L, 46.8 mg/L, respectively, although they were treated hemodialysis. Results of the working environment measurement showed that the concentration of methyl alcohol (1030.1–2220.5 ppm) in the air exceeded the time weighted average (200 ppm). They were diagnosed with optic neuropathy due to methyl alcohol poisoning and still have visual impairment. CONCLUSIONS: Workers who hired as dispatched employees in a small-sized subcontracted factory were exposed to high concentrations of methyl alcohol. The workplace had poor ventilation system. In addition, workers did not wear proper personal protect equipment. Working environment measurement and annual chekups for workers were not performed. They were in a blind spot to occupational safety and health. More attention is needed to protect vulnerable workers’ health.
Acidosis ; Aluminum* ; Dyspnea ; Ethanol ; Female ; Humans ; Inhalation* ; Korea ; Male ; Methanol* ; Myalgia ; Occupational Health ; Optic Disk ; Optic Nerve Diseases ; Poisoning ; Renal Dialysis ; Smartphone ; Sodium Bicarbonate ; Ventilation ; Vision Disorders

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare and fatal cancer-related pulmonary complication leading to severe pulmonary hypertension, right heart failure, and death. Few cases of PTTM have been diagnosed antemortem. A 62-year-old male showing complete remission of gastric cancer presented with exertional dyspnea. Transthoracic echocardiography showed marked dilation of the right atrium, right ventricle, and the small left ventricle with normal left ventricular function. Right heart catheterization also showed mild to moderate pulmonary hypertension. A chest computed tomography scan revealed no evidence of acute pulmonary thromboembolism, but it showed consolidations with subpleural nodules in both lower lobes, and a lung perfusion scan showed multifocal, non-segmental perfusion defects. Finally, a diagnostic lung biopsy with video-assisted thoracoscopic surgery was performed, and the pathologic findings were compatible with PTTM. Here, we report a case of gastric cancer-related PTTM that was diagnosed antemortem.
Biopsy ; Cardiac Catheterization ; Cardiac Catheters ; Dyspnea ; Echocardiography ; Heart Atria ; Heart Failure ; Heart Ventricles ; Humans ; Hypertension, Pulmonary ; Lung ; Male ; Middle Aged ; Perfusion ; Pulmonary Embolism ; Stomach Neoplasms* ; Thoracic Surgery, Video-Assisted ; Thorax ; Thrombotic Microangiopathies* ; Ventricular Function, Left

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare and fatal cancer-related pulmonary complication leading to severe pulmonary hypertension, right heart failure, and death. Few cases of PTTM have been diagnosed antemortem. A 62-year-old male showing complete remission of gastric cancer presented with exertional dyspnea. Transthoracic echocardiography showed marked dilation of the right atrium, right ventricle, and the small left ventricle with normal left ventricular function. Right heart catheterization also showed mild to moderate pulmonary hypertension. A chest computed tomography scan revealed no evidence of acute pulmonary thromboembolism, but it showed consolidations with subpleural nodules in both lower lobes, and a lung perfusion scan showed multifocal, non-segmental perfusion defects. Finally, a diagnostic lung biopsy with video-assisted thoracoscopic surgery was performed, and the pathologic findings were compatible with PTTM. Here, we report a case of gastric cancer-related PTTM that was diagnosed antemortem.
Biopsy ; Cardiac Catheterization ; Cardiac Catheters ; Dyspnea ; Echocardiography ; Heart Atria ; Heart Failure ; Heart Ventricles ; Humans ; Hypertension, Pulmonary ; Lung ; Male ; Middle Aged ; Perfusion ; Pulmonary Embolism ; Stomach Neoplasms* ; Thoracic Surgery, Video-Assisted ; Thorax ; Thrombotic Microangiopathies* ; Ventricular Function, Left

STUDY DESIGN: Retrospective study. PURPOSE: To assess the feasibility and limitations of fracture risk assessment tool (FRAX) for osteoporotic vertebral fractures in the Korean population. OVERVIEW OF LITERATURE: The FRAX algorithm is country specific and uses clinical risk factor data to calculate an individual patient's 10-year probability of hip fracture and 10-year probability of major osteoporotic fracture. However, it has not been adequately investigated for Korean. METHODS: One hundred ninety four patients who had all risk factor data for the calculation of FRAX were divided into two groups depending on the existence of vertebral fractures: the fracture group was comprised of 88 patients and the non-facture group comprised of 105 patients. We analyzed prediction of the fracture by applying respectively the Korean, Japanese, USA and UK model, and compared their FRAX results by calculating lumbar bone mineral density (BMD) instead of femoral neck BMD. RESULTS: The prediction of vertebral fracture using FRAX was 10.9 +/- 6.2% in the fracture group, 9.5 +/- 5.5% of the non-fracture group in the Korean model (p = 0.108); 17.9 +/- 10.2% in the fracture group, 14.6 +/- 9.0% in the non-fracture group in the Japanese model (p = 0.017). Only the Japanese model exhibited significant difference in vertebral fracture risk. The prediction of vertebral fracture using lumbar BMD instead of femoral neck BMD was 19.5 +/- 12.1% in the fracture group, 16.0 +/- 10.3% in the non-fracture group in the Korean model (p = 0.029). All models had statistically significant differences for the prediction of osteoporotic vertebral fracture. CONCLUSIONS: The 10-year probability of osteoporotic vertebral fracture had underestimation of the risk considering treatment eligibility based on the National Osteoporosis Foundation guidelines. BMD that accurately reflects the contribution of each result to fracture risk should be preferred for the prediction of fracture using FRAX, when lumbar spine and hip BMD measurements are both performed for clinical purposes in Korean.
Asian Continental Ancestry Group ; Bone Density ; Femur Neck ; Hip ; Humans ; Korea ; Osteoporosis ; Osteoporotic Fractures ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Spine

No abstract available.
Calcinosis* ; Humans ; Infant*

PURPOSE: Laparoscopic gastrectomy in obese patients has been investigated in several studies, but its feasibility has rarely been examined in morbidly obese patients, such as in those with a body mass index (BMI) of > or =30 kg/m2. The present study aimed to evaluate the technical feasibility and safety of laparoscopic gastrectomy in morbidly obese patients with gastric cancer. MATERIALS AND METHODS: A total of 1,512 gastric cancer patients who underwent laparoscopic distal gastrectomy (LDG) were divided into three groups: normal (BMI<25 kg/m2, n=996), obese (BMI 25~30 kg/m2, n=471), and morbidly obese (BMI> or =30 kg/m2, n=45). Short-term surgical outcomes, including the course of hospitalization and postoperative complications, were compared between the three groups. RESULTS: The morbidly obese group had a significantly longer operating time (240 minutes vs. 204 minutes, P=0.010) than the normal group, but no significant differences were found between the groups with respect to intraoperative blood loss or other complications. In the morbidly obese group, the postoperative morbidity and mortality rates were 13.3% and 0%, respectively, and the mean length of hospital stay was 8.2 days, which were not significantly different from those in the normal group. Subgroup analysis showed that postoperative complication rates were not high in morbidly obese patients, independent of the type of anastomosis technique used and level of lymph node dissection. CONCLUSIONS: LDG is technically feasible and safe in morbidly obese patients with a BMI of > or =30 kg/m2 and early gastric carcinoma. Except for a longer operating time, LDG might represent a reasonable treatment option in these patients.
Body Mass Index ; Gastrectomy* ; Hospitalization ; Humans ; Korea ; Laparoscopy ; Length of Stay ; Lymph Node Excision ; Mortality ; Obesity, Morbid ; Postoperative Complications ; Stomach Neoplasms*

PURPOSE: Information regarding antimicrobial prophylaxis (AMP) for gastric cancer surgery is limited. The present study investigated the efficacy of single-dose AMP for the prevention of surgical site infection (SSI) in patients undergoing gastrectomy for gastric carcinoma. MATERIALS AND METHODS: Between 2011 and 2013, 1,330 gastric carcinoma surgery patients were divided into two AMP administration groups depending on the duration of treatment. Postoperative outcomes including morbidity and SSI were compared between the two groups overall and in matched patients. Risk factors for SSI were analyzed. RESULTS: The extended group (n=1,129) received AMP until postoperative day 1 and the single-dose group (n=201) received singledose AMP only during an operation. Postoperatively, there were no significant differences between the two groups with respect to overall morbidity, mortality, or length of hospital stay. The SSI rate of the single-dose group was not significantly different from that of the extended group overall (4.5% vs. 5.5%, respectively, P=0.556) or in matched patients (4.5% vs. 4.0%, respectively, P=0.801). There was no increase in the SSI rate of the single-dose group compared to the extended group in subgroups based on different clinicopathological and operative factors. Univariate and multivariate analyses revealed male gender, open surgery, and operating time (> or =180 minutes) as independent risk factors for SSI. CONCLUSIONS: Single-dose AMP showed no increase in the postoperative SSI rate compared to postoperative extended use in patients undergoing gastrectomy for gastric carcinoma. The efficacy of single-dose AMP requires further investigation in randomized clinical trials specific to gastric cancer surgery.
Antibiotic Prophylaxis ; Gastrectomy* ; Humans ; Length of Stay ; Male ; Mortality ; Multivariate Analysis ; Risk Factors ; Stomach Neoplasms ; Surgical Wound Infection

OBJECTIVE: To investigate long-term functional changes and its underlying factors in stroke patients. METHOD: Data were collected retrospectively from the stroke patients who had been completed at least 2 times of functional evaluation after discharge. 60 stroke patients were included and we investigated long-term change of motor, cognition and activities of daily living score at 6 months from the onset and the last score during the follow up period. The motor function included manual function test (MFT), Korean version of Berg balance scale (K-BBS), cognitive function by Korean version of mini-mental status examination (K-MMSE), activities of daily living by Korean version of modified Barthel index (K-MBI). To identify the factors influencing long-term function outcome after stroke, biographical data and risk factors were collected and bivariate correlation analysis was performed. RESULTS: The mean duration of follow-up was 23.4 months and MFT, BBS, MMSE, and K-MBI scores showed no significant difference between 6 months from the onset and final evaluation. History of recurrent stroke (p = 0.007) and hypertension (p = 0.017) were significantly related with decline of cognition during follow up period. All the other independent variables were not statistically significant. CONCLUSION: None of the function showed significant changes during the 2 year of mean follow-up period. Recurrent stroke and hypertension were significant predictor for decline of cognitive function. Our results suggest that secondary prevention including blood pressure control is important to prevent decline of cognitive function after stroke.
Activities of Daily Living ; Blood Pressure ; Cognition ; Follow-Up Studies ; Humans ; Hypertension ; Postural Balance ; Retrospective Studies ; Risk Factors ; Secondary Prevention ; Stroke ; Upper Extremity