Comparison of apical transportation and change of working length in K3, NRT AND PROFILE rotary instruments using transparent resin block / 대한치과보존학회지

OBJECTIVES: The purpose of this study is to compare the apical transportation and working length change in curved root canals created in resin blocks, using 3 geometrically different types of Ni-Ti files, K3, NRT, and Profile. MATERIALS AND METHODS: The curvature of 30 resin blocks was measured by Schneider technique and each groups of Ni-Ti files were allocated with 10 resin blocks at random. The canals were shaped with Ni-Ti files by Crown-down technique. It was analyzed by Double radiograph superimposition method (Backman CA 1992), and for the accuracy and consistency, specially designed jig, digital X-ray, and CAD/CAM software for measurement of apical transportation were used. The amount of apical transportation was measured at 0, 1, 3, 5 mm from 'apical foramen - 0.5 mm' area, and the alteration of the working length before and after canal shaping was also measured. For statistics, Kruskal-Wallis One Way Analysis was used. RESULTS: There was no significant difference between the groups in the amount of working length change and apical transportation at 0, 1, and 3 mm area (p = 0.027), however, the amount of apical transportation at 5 mm area showed significant difference between K3 and Profile system (p = 0.924). CONCLUSIONS: As a result of this study, the 3 geometrically different Ni-Ti files showed no significant difference in apical transportation and working length change and maintained the original root canal shape.

Surgical removal of a left ventricular thrombus caused by acute myocarditis / 소아과

Left ventricular thrombus is mainly caused by anterior myocardial infarction or severe cardiac wall dysfunction of the apex, and is rarely caused by a complication of acute myocarditis. A 12-year-old female who developed symptoms of motor dysphasia and incomplete hemiparesis of the right side was admitted to the hospital. The brain MRI taken on the day of her admission showed acute cerebral infarction in the left basal ganglia and the frontoparietal lobe. The echocardiogram showed a movable thrombus, which was 19x28 mm sized and located in the apex of the left ventricle. So in order to prevent further thromboembolic event we performed open cardiac surgery via the atrium and removed the thrombus of the left ventricle. After the removal of the thrombus her symptoms improved and she was discharged from the hospital. Thrombus formation in acute viral myocarditis are considered to be related with endocardial injury and blood flow stasis. Treatment with anticoagulants in left ventricular thrombosis may not be effective and may even cause a major thromboembolism. When the thrombus is laminar and fixed, one should consider anticoagulant therapy. But if the thrombus is pedunculated and movable, which means that there are higher possibilities of major embolism or there may be already one, one should consider surgical removal. We report a 12-year-old girl who required surgical removal of a left ventricular thrombus caused by acute viral myocarditis.