Vladimir Ivanovic

Temperature changes in silorane-, ormocer-, and dimethacrylate-based composites and pulp chamber roof during light-curing.

STATEMENT OF THE PROBLEM Light-curing of resin-based composites (RBCs) is associated with temperature increase in the pulp chamber, which may have a detrimental effect on the vital pulp. PURPOSE The purpose of the study was to evaluate temperature changes of silorane-, ormocer-, and dimethacrylate-based RBCs at the bottom surface of the RBC and in the pulp chamber roof dentin (PCRD) during curing. MATERIALS AND METHODS In part A, temperatures were measured for Filtek LS (3M ESPE, St. Paul, MN, USA), Admira (Voco GmbH, Cuxhaven, Germany), and Herculite XRV (Kerr Corp., Orange, CA, USA) with a high-power light-emitting diode (LED) unit by placing thermocouples in contact with the bottom surface of the material in standardized acrylic molds. In part B, temperature changes in PCRD were measured in extracted molars during light-curing of adhesives and RBCs in 2-mm-deep cavities with a remaining dentin thickness (RDT) of 1 mm. RESULTS Filtek LS showed a different temperature curve compared with Admira and Herculite XRV. Significantly higher temperatures were recorded for Filtek LS (p < 0.001) than for Admira and Herculite XRV in acrylic molds. Temperature rises recorded in PCRD for adhesives and RBCs were between 4.1 and 6.4 degrees C. No significant differences in PCRD temperatures were found between the three groups during adhesive curing and RBC curing (p > 0.05). CONCLUSIONS Filtek LS showed a different heat-generation pattern from and significantly higher temperatures than Admira and Herculite XRV when the materials were tested in acrylic molds. Similar temperatures were recorded in the PCRD during curing of adhesives and RBCs. CLINICAL SIGNIFICANCE Although a substantial temperature rise in the bulk material occurred during light-curing of the three resin-based composites, a remaining dentin thickness of 1 mm caused a significant reduction in pulp chamber roof dentin temperatures. Temperatures measured in the pulp chamber roof dentin corresponding to the zone occupied by the postmitotic odontoblast layer were not statistically different for the three types of resin-based composites.

MR angiography fusion technique for treatment planning of intracranial arteriovenous malformations

To develop an image fusion technique using elliptical centric contrast‐enhanced (CE) MR angiography (MRA) and three‐dimensional (3D) time‐of‐flight (TOF) acquisitions for radiosurgery treatment planning of arteriovenous malformations (AVMs).

Carotid-Carotid Bypass as an Option in the Treatment of Infected Pseudoaneurysm After Prosthetic Carotid Replacement

Development of pseudoaneurysm from an infected carotid prosthetic patch after carotid endarterectomy is extremely rare and is very challenging from the perspective of surgical and medical treatment. This article describes the case of a 65-year-old patient presenting with the signs of wound infection and recurrent bleeding in the region of the right carotid artery. Three years earlier the patient underwent coronary artery bypass grafting and bilateral replacement of carotid arteries with prosthetic tube grafts. Magnetic resonance imaging confirmed the presence of an infected pseudoaneurysm in the region of prosthetic carotid replacement graft. A decision was made to perform retroesophageal carotid-carotid bypass with an autologous venous conduit.

An unusual origin of proximal coronary bypass anastomosis in a patient with porcelain aorta: how we solved the problem.

Severe calcification of the ascending aorta (porcelain aorta) is a very difficult condition in cardiac surgery because of a high embolization potential during the process of cannulation, aortic cross-clamping and a particular difficulty to suture the proximal anastomosis. We described a case of a 68-year-old female referred to our Institute due to unstable angina. Further diagnostics revealed a severe high grade, multilevel fibrolipid symptomatic carotid stenosis and ostial left main coronary artery stenosis and a highly calcified ascending aorta and aortic arch. We performed simultaneous carotid segment replacement with the Dacron prosthesis and revascularisation of the left anterior descending coronary artery. Proximal venous anastomosis was created in the Dacron prosthesis of the right carotid artery. Perfusion of the patient was achieved via the graft sutured at the right subclavian artery due to impossibility of direct aortic cannulation.

Accuracy of three electronic apex locators in determining the apical foramen in multi‐rooted teeth: Randomised clinical and laboratory study

This study aimed to compare the accuracy of three electronic apex locators (EALs), Raypex 5, Apex NRG and ProPex II, in locating the apical foramen (AF) in vivo. Thirty multi-rooted teeth were included in the study. Distances from the file tip to the radiographic apex from the buccal (R1) and mesial (R2) aspect were measured after extraction. The distance from the file tip to the AF (L) was measured microscopically. Raypex 5, Apex NRG and ProPex II were accurate to within ± 0.5 mm in 84.6%, 78.6% and 66.7% of cases, respectively. R1, R2 and L measurements between the EALs were not statistically different (P > 0.05). R1 and L correlated positively (r(2) = 0.817; P < 0.001). There were no significant differences in all measurements between vital and non-vital root canals (P > 0.05). There was no statistically significant difference between the EALs. There was a positive correlation between electronic and radiographic measurements when locating the AF.

Posterior wall myocardial infarction: A case report

Acute myocardial infarction is a clinical manifestation of coronary disease which occurs when a blood vessel is narrowed or occluded in such a way that it leads to irreversible myocardial ischemia [1, 2]. Acute ST elevation myocardial infarction (STEMI) is diagnosed based on clinical presentation, newonset persistent elevation registered on electrocardiogram (ECG) in at least two leads i.e. transitory ST elevation longer than 20 minutes, and positive cardiospecific enzymes [3]. In certain cases chest pain along with the signs of ischemia on ECG and cardiospecific enzymes can have origins other than coronary, like in myopericarditis [4]. Equivalents to ST elevation myocardial infarction represent a great diagnostic problem. They are: ST segment elevation in aVR lead indicating left main coronary artery stenosis, the left bundle branch block in myocardial infarction, and posterior myocardial infarction [5, 6]. In Summary Introduction. Acute myocardial infarction is a clinical manifestation of coronary disease which occurs when a blood vessel is narrowed or occluded in such a way that it leads to irreversible myocardial ischemia. ST segment depression in leads V1−V3 on the electrocardiogram points to the anterior wall ischemia, although it is actually ST elevation with posterior wall myocardial infarction. In the absence of clear ST segment elevation, it may be overlooked, leading to different therapeutic algorithms which could significantly affect the outcome. Case report. A 77 year-old female patient was admitted to the Coronary Care Unit due to prolonged chest pain followed by nausea and horizontal ST segment depression on the electrocardiogram in V1−V3 up to 3 mm. ST segment elevation myocardial infarction of the posterior wall was diagnosed, associated with the development of initial cardiogenic shock and ischemic mitral regurgitation. An emergency coronarography was performed as well as primary percutaneous coronary intervention with stent placement in the circumflex artery, the infarct-related artery. Due to a multi-vessel disease, surgical myocardial revascularization was indicated. Conclusion. Posterior wall transmural myocardial infarction is the most common misdiagnosis in the 12 lead electrocardiogram reading. Routine use of additional posterior (lateral) leads in all patients with chest pain has no diagnostic or therapeutic benefits, but it is indicated when posterior or lateral wall infarction is suspected. The use of posterior leads increases the number of diagnosed ST segment elevation myocardial infarctions contributing to better risk assessment, prognosis and survival due to reperfusion therapy.

Late complications of transcatheter atrial septal defect closure requiring urgent surgery

A 21-year-old female patient was transferred to our hospital after being diagnosed with massive pulmonary thromboembolism (PTE). Three years prior to admission, she underwent transcatheter closure of the secundum ASD with a 33 mm CardioSEAL-StarFLEX occluder (NMT Medical, Boston, MA, USA). A year ago, she was involved in a car accident and sustained significant blunt chest trauma. Transthoracic echocardiography confirmed the presence of thrombi in the right atrium and the pulmonary artery, with massive dilatation of the right ventricle and the pulmonary artery, along with severe pulmonary hypertension. Also, protrusion or dislodgement of the occluder was suspected. Her deteriorated clinical conditions warranted immediate surgery. The patient was put on a cardiopulmonary bypass (CPB) and the right atrium and the pulmonary artery were opened. Several thrombi were removed, the largest being 2 × 3 cm. The ASD occluder was identified with a thrombus attached to it and evident device-arm fracture (Figure 1). The occluder underwent almost complete healing with full endocardium covering except in the rim area. The device was removed and the ASD was repaired with a patch. Unfortunately, due to right heart failure, the patient could not be successfully weaned from the CPB, not even after an artificially created interatrial shunt, and she expired. Although one cannot say with absolute certainty that massive PTE developed because of device-related thrombosis, it seems intuitive that blood turbulence around the protruded umbrella and device-arm fracture could have acted as a nidus for repeated thrombus formation with subsequent embolization. The occluder malfunction (fracture) was most likely the result of sustained blunt chest trauma a year prior to admission. We hypothesize that the sudden increase in intrathoracic pressure during trauma as well as direct compression on the heart generated a point of high wall stress around the occluder’s septal insertion, which may have led to device fracture and dislodgment.

First application of automated external defibrilator in Serbia: Case report

INTRODUCTION Sudden cardiac death is an unexpected natural death from cardiac causes. It is the most common and first manifestation of coronary artery disease. It accounts for 50% of mortality from cardiovascular disease in the United States of America and other developed countries, so measures that can reduce it are an important medical task. CASE REPORT A 55-year old man suddenly lost consciousness at the train station in Novi Sad. An eyewitness provided first aid and ventricular fibrillation was converted to sinus rhythm by means of the automated external defibrillator. Emergency Medical Service Novi Sad soon arrived, continued resuscitation procedure, and transported the patient to the Cardiac Care Unit, who was then diagnosed with acutedmyocardial infarction and primary percutaneous coronary intervention was performed. Resuscitative hypothermia was applied in acute phase to prevent further brain injury. During further hospitalization the patient was stable, woke up from coma and early rehabilitation measures were implemented. After six months the patient had normal physical activities and there was no left ventricular segmental hypokinesia on echo cardiography. CONCLUSION The application of all four chains of survival is important in increasing the survival rate of patients with sudden cardiac arrest.

Myocardial Perfusion Imaging in Diagnosis of Culprit Lesion in Patients Undergoing Elective Percutaneous Coronary Intervention

Myocardial perfusion imaging (MPI) was developed in the 1970s and has been used increasingly in clinical cardiology since the 1980s (Underwood et al., 2004). Technical developments that have fuelled this recent increases are single-photon emission computed tomography (SPECT) imaging, pharmacological stress and ECG-gated SPECT imaging. MPI comprises the only widely available method of assessing myocardial perfusion directly and many previously published reports support its evidence in the diagnosis of myocardial ischemia and necrosis. Moreover, the prognostic value of this method for patients’ risk stratification has already been extensively reported, with an incremental prognostic value after clinical assessment, exercise electrocardiography and even above coronary angiography. Thus, MPI is an established imaging technique that is already an integral part of the management of coronary artery disease (CAD) (diagnosis, prognostication, selection for revascularization and assessment of acute coronary syndromes) and is included in a number of professional guidelines. (1, 2) In the past two decades, a great body of literature has established the use of nuclear imaging for risk stratification in patients with known or suspected CAD. Risk stratification is of crucial importance for the practice of contemporary medicine. Extending the paradigm of noninvasive cardiac testing beyond the detection of disease is especially important, may risk assessment permits patients who are identified as being at a high risk for subsequent cardiac events should receive aggressive management, possibly including cardiac catheterization for potential revascularization procedures that may improve their outcome. Conversely, the management focus in patients with low future event rate should be shifted toward risk factor modification and aggressive medical therapy, reserving invasive procedures for

Effect of prolonged thermal cycling on microleakage around Class V cavities restored with glass-ceramic inserts with different coefficients of thermal expansion: an in vitro study.

Purpose The purpose of this in vitro study was to evaluate microleakage around Class V glass-ceramic restorations of different coefficients of thermal expansion after prolonged thermal cycling. Materials and Methods One hundred and twenty non-carious extracted human premolars (patient age range 12–20 years) were randomly assigned to three groups. Standard Class V preparations were cut in the buccal surface using customised Cerana burs, size no. 3. Glass-ceramic inserts from two manufacturers (Cerana, Nordiska Dental AB, Helsingborg, Sweden; Beta-Quartz, Hager & Werken GmbH, Duisburg, Germany) were used to restore the cavities and were luted with a hybrid, high-viscous composite (Tetric Ceram, Ivoclar Vivadent, Schaan, Liechtenstein) and a bonding agent (Excite, Ivoclar Vivadent, Schaan, Liechtenstein). A control group, without inserts, was bulk-filled with the same composite used as the luting agent. In accordance with American Dental Association guidelines, half of the preparation was in enamel, half in dentine/cementum and had a mesio-distal width of 3 mm, an occluso-gingival height of 3 mm, and a depth of 2 mm. All margins had butt joints. Sixty teeth, selected at random, were not thermal cycled; the remaining 60 teeth were thermal cycled 4000 times between water baths held at 5°C and 55°C and the specimens prepared and examined for microleakage using 2.0% Procion Red® (ICI, Slough, UK) dye, buffered at pH7, as a marker. The results were analysed using the Kruskal-Wallis test (ANOVA) at a 95% significance level. Results At the occlusal margins there was no significant difference in microleakage between the three groups (P>0.5) without thermal cycling. After thermal cycling, microleakage at the occlusal margins was significantly less around cavities restored with Cerana glass-ceramic inserts versus Beta-Quartz and Tetric Ceram (P<0.05 in both cases). At the gingival margins, there was no significant difference in microleakge between the groups before thermal cycling (P>0.5). After thermal cycling, there was significantly less microleakage between Cerana inserts and Tetric Ceram (P<0.05). Comparisons between non-thermal cycled and thermal cycled groups showed there was no significant difference with the Cerana inserts (P=0.5590). Clinical Implications The results indicate that, after thermal cycling, restorations restored with Cerana glass-ceramic inserts, which have a coefficient of thermal expansion approximating to that of enamel, show a decrease in marginal microleakage, compared with Beta-Quartz glass-ceramic inserts and Tetric Ceram resin-based composite material. Restorative materials, which have a coefficient of thermal expansion approximating to that of enamel, would seem to be the materials of choice in reducing the problem of marginal microleakege.