A Finite Element Method Study on a Simulation of the Thermal Behaviour of Four Methods for the Restoration of Class II Cavities.

The possibility of dental pulp damage during dental procedures is well known. According to studies, during finishing and polishing without cooling, temperatures of up to 140 °C or more can be generated. There are many studies that have analysed the influence of the finishing and polishing of fillings on the mechanical parameters, but the analysis of thermal parameters has led to uncertain results due to the difficulty of performing this in vivo. Background: We set out to conduct a study, using the finite element method, to determine the extent to which the type of class II cavity and the volume of the composite filling influence the duration of heat transfer to the pulp during finishing and polishing without cooling. Materials and Methods: A virtual model of an upper primary molar was used, with a caries process located on the distal aspect, in which four types of cavities were digitally prepared: direct access, horizontal slot, vertical slot and occlusal-proximal. All four cavity types were filled using a Filtek Supreme XT nanocomposite. Results: The study showed that the filling volume almost inversely proportionally influences the time at which the dental pulp reaches the critical temperature of irreversible damage. The lowest duration occurred in occlusal-distal restorations and the highest in direct access restorations. Conclusions: based on the results of the study, a working protocol can be issued so that finishing and polishing restorations without cooling are safe for pulpal health.

Study on the Restoration of Class II Carious Cavities by Virtual Methods: Simulation of Mechanical Behavior.

The restoration of class II cavities is predominantly carried out with composite materials. Due to the high failure rate in restoring this type of cavity, composite materials with much-improved properties and new application techniques have been promoted. The study aimed to analyze the mechanical behavior of several topical composite materials (nanocomposites, nanohybrids and ormocer) using different application techniques. In a lower second molar, a class II occlusal cavity was prepared. As filling materials, we used the following combinations: Admira Fusion and Admira Fusion Flow, Grandio and Grandio Flow, Filtek Supreme XT and Filtek Supreme Flow. These were applied using a snow plow, injection molded and Bichacho techniques. Three-dimensional scanning of the molar with the prepared cavity was performed, and then scanning of each layer of added composite material was performed, obtaining three-dimensional models. The virtual molar models were analyzed with software specific to the finite element analysis method, where their physical-mechanical properties were entered and assigned to the components of the virtual molar. Simulations at high forces specific to bruxism were then carried out and analyzed, and compared. The values of displacements and strain, for all six analyzed situations, are relatively small (range from 5.25 × 10-6-3.21 × 10-5 for displacement, 6.22 × 10-3-4.34 × 10-3 for strain), which validates all three methods and the materials used. As far as the stress values are concerned, they are similar for all methods (250-300 MPa), except for the snow plow and injection-molded techniques using Grandio and Grandio Flow composites, where the maximum von Mises stress value was more than double (approximately 700 MPa). When using the combination of Grandio and Grandio Flow materials, the 1 mm thickness of the fluid composite layer was found to have a major influence on occlusal forces damping as opposed to 0.5 mm. Therefore, the Bichacho technique is indicated at the expense of the snow plow and injection-molded techniques. The composite materials used by us in this study are state-of-the-art, with clear indications for restoring cavities resulting from the treatment of carious lesions. However, their association and application technique in the case of Class II cavities is of clinical importance for resistance to masticatory forces.

Decrease of glutathione peroxidase in arrhythmic cardiac pathology in young individuals and its therapeutic implications.

Glutathione peroxidase (GPx), as an antioxidant enzyme, is involved in the regulation of processes that cause cellular oxidative stress, with implications in various pathologies. The aim of the present study was to evaluate GPx variations in patients with arrhythmic, non-structural cardiac disorders. The research was performed on 120 patients, with a mean age of 33 years old, divided into 3 equal groups, of which 2 groups included patients with cardiac arrhythmias, the first group, associated with dyslipidemia and the second one, without dyslipidemia, and a control group consisting of healthy individuals. The method for determining GPx was based on the GPx enzyme catalysis reaction of the reduced glutathione (GSH) oxidation reaction by cumene hydroperoxide. The results revealed that GPx variation was decreased in patients with cardiac arrhythmias, with or without dyslipidemia, up to 66 and 74% of mean control values, respectively, the differences being statistically significant, showing the existence of an oxidative stress imbalance, that may be involved in triggering arrhythmogenic electrochemical mechanisms. The GPx deficiency determined in relation to cardiac arrhythmias was in dyslipidemic and non-lipidemic patients as follows: 29-35% in sinus bradycardia, 31-35% in associated cardiac arrhythmias, 30-33% in sinus tachycardia, 27-33% in atrial fibrillation, 32-33% in atrial flutter, 27-32% in atrial extrasystolic arrhythmia, 28-30% in ventricular extrasystolic arrhythmia and 18-26% in paroxysmal supraventricular tachycardia. Collectively, the results revealed that GPx, an antioxidant enzyme, is a specific biomarker, whose decrease indicated the existence of oxidative stress in young individuals with cardiac arrhythmias and its involvement in arrhythmogenic electrochemical processes. In addition, GPx deficiencies were between 18-35% in all types of cardiac arrhythmias, the highest being recorded in sinus bradycardia and the lowest in paroxysmal supraventircular tachycardia. Furthermore, the oxidative stress favored by the decrease of GPx induced lipid oxidation, regardless of the presence or absence of dyslipidemia, which triggered the formation of anti-lipid antibodies and a subclinical endothelial aggression, with early atherosclerotic potential. GPx evaluation may argue for the existence of oxidative stress in non-structural cardiac arrhythmias, and by its proper correction (antioxidants), prophylaxis of atherogenic dysfunction.

Mortality Rate in Upper Gastrointestinal Bleeding Associated with Anti-Thrombotic Therapy Before and During Covid-19 Pandemic.

Introduction: During the last few years, a progressive higher proportion of patients have had upper gastrointestinal bleeding (UGIB) related to antithrombotic therapy. The introduction of direct oral anticoagulant (DOAC) and COVID-19 pandemic may change the incidence, mortality, and follow-up, especially in patients at high risk of bleeding. Patients and Methods: We studied the use of anti-thrombotic therapy (AT) in patients with upper gastrointestinal bleeding for 5 years (January 2017-December 2021) including Covid-19 pandemic period (March 2020-December 2021). We analyzed mortality rate, rebleeding rate and need for transfusion in patients with AT therapy compared with those without AT therapy and risk factors for mortality, and also the incidence of gastrointestinal bleeding in patients admitted for COVID-19 infection. Results: A total of 824 patients were admitted during Covid-19 pandemic period and 1631 before pandemic period; a total of 426 cases of bleeding were recorded in patients taking antithrombotic therapy and the frequency of antithrombotic therapy in patients with UGIB was higher in pandemic period (24.39% versus 13.8%). Unadjusted mortality was 12.21%, similar with patients with no antithrombotic treatment but age-adjusted mortality was 9.62% (28% lower). The rate of endoscopy was similar but fewer therapeutic procedures were required. Mean Hb level was 10% lower, and more than 60% of patients required blood transfusion. Conclusion: Mortality was similar compared with patients with no antithrombotic therapy, fewer therapeutic endoscopies were performed and similar rebleeding rate and emergency surgery were noted. Hb level was 10% lower and a higher proportion of patients required blood transfusions. Mortality was higher in DOAC treatment group compared with VKA patients but with no statistical significance. The rate of upper gastrointestinal bleeding in Covid-19 positive hospitalized cases was 0.58%. The mortality risk in multivariate analysis was associated with GB score, with no endoscopy performed, with obscure and variceal bleeding and with LMWH versus VKA therapy.

Variation of Total Antioxidant Activity in Young People with Non-Lesional Cardiac Arrhythmias.

Total antioxidant activity status (TAS) represents the body's response to oxidative stress, important in the pathogenic assessment of oxidations. AIM: To determine TAS variations in young subjects, with non-lesional cardiac arrhythmias, with/without dyslipidemia and to assess the risk of lipid oxidation. PATIENTS AND METHODS: The research was performed on 120 young subjects (mean age 33 years), with various types of cardiac arrhythmias, on normal heart, without co-existing lesions. Subjects were divided into 3 groups (40 persons). The first 2 groups included subjects with cardiac arrhythmias. Group I also associated dyslipidemia; group II, without dyslipidemia and group III: control. Determination of TAS values was performed using ABTS (2-azino-di-3-ethylbenzthiazoline sulfonate) colorimetic method. Results were statistically processed. RESULTS: TAS values were decreased in all patients with cardiac arrhythmias, representing 52-54% of the values of healthy controls, the data being highly statistically significant. The variation of TAS decrease by types of arrhythmias was thus found in patients with arrhythmias and associated dyslipidemia and, respectively, without dyslipidemia, compared to controls. The deficit of antioxidant activity, between 48%-46% triggers electrochemical processes with implications in arrhythmogenesis and lipid oxidation. Coffee and vegetables-rich diet have antioxidant effect, reducing TAS deficiency. CONCLUSIONS: 1. TAS was decreased in all subjects with non-lesional arrhythmias. The study showed decreasing TAS level at 52-54% in patients with arrhythmias, with/without dyslipidemia, compared to controls. 2. TAS deficiency was associated with various types of dysrhythmias, ranging from 62% to 33%. 3. Decreased TAS also triggers lipid oxidation, as risk factor for early atherosclerotic lesions.

Correlations between endothelial cell markers CD31, CD34 and CD105 in colorectal carcinoma.

PURPOSE: Colorectal carcinoma is an important cause of mortality worldwide. The fact that tumor growth is dependent on angiogenesis has supported researches for new prognostic parameters and the development of novel therapeutic strategies. Accordingly, we sought to evaluate angiogenesis quantitatively by assessing microvessel density in colorectal cancer. MATERIALS AND METHODS: The blood vessels stained with CD31, CD34 and CD105 were counted, and we reported their number per square millimeter in order to obtain microvascular density (MVD). Then, we aimed at comparing the performance of three endothelial cell markers (CD31, CD34, and CD105) on formalin-fixed tissues from 58 patients diagnosed with colorectal cancer. RESULTS: Following the comparison of the average effective vessels marked with the three markers, Student's t-test showed that the mean number of blood vessels marked with CD34 is higher than the blood vessels marked with CD31 and CD105. A significant difference that has been registered between the three levels of the T stage was found in the patients in our study, in terms of value marker CD105, ANOVA p=0.049, which returns to a value <0.05. Quick time decreases the pT stage, the observed differences being close to statistical significance. However, the result of ANOVA test does not allow us to say that differences can be generalized and not just a particular result, valid only for the study group, p=0.061 >0.05. There is a significant difference between patients with stage T, in terms of value: hemoglobin (ANOVA p<0.001), hematocrit (ANOVA p<0.001), mean corpuscular volume (MCV) (ANOVA p<0.001), mean corpuscular hemoglobin (MCH) (ANOVA p=0.002 <0.01 - significant difference with 99% confidence). By calculating the Pearson's correlation coefficient for the relationship CD31-CD105, we obtained a value r=0.440, which corresponds to p=0.0013 <0.05, indicating a statistically noteworthy direct correlation between the two factors. CONCLUSIONS: CD31 marker increases simultaneously with the CD105, in the cases analyzed throughout the present study. The ability of tumors to maintain a high vascular blood density in their inner portions may represent a reliable parameter to evaluate tumor angiogenesis and a finding relevant for future development of therapeutic angiogenesis strategies.

Visceral and tissular reactivity in acute heart failure due to supraventricular tachyarrhythmia in a young patient.

Observation of major pathological alterations in a young person involves etiological and clinical justifications, in order to properly assess, treat and control these conditions. The aim of this paper is to present severe, acute pathological lesions, installed in a young person, secondary to hypodiastolic heart failure, due to persistent supraventricular tachyarrhythmia, triggered by a post-traumatic external stimulus, with complete remission post-electrical conversion. Pathological and clinical modification are revealed, in a young person, shortly after a minor thoracic trauma, in the absence of traumatic injury but with high-frequency palpitations onset and progressive installation of vascular, visceral and interstitial stasis modifications, as well as of vascular and tissular hypoperfusion with reactive vasoconstriction. These clinical and paraclinical aspects were: stasis hepatomegaly with hepatojugular reflux, pulmonary congestion with stasis rales, peripheral edema, transudative polyserositis - pericarditis, hydrothorax, ascites, dilatation of inferior vena cava and suprahepatic veins, decrease of arterial blood pressure, tissue and cutaneous vasoconstriction. Anatomical and clinical aspects, with major alterations (Vth degree hepatomegaly, polyserositis, peripheral edema, tachyarrhythmic heart contractions, hypotension, pallor accentuated by vasoconstriction) acutely installed in a previously healthy young person, require a rapid lesions diagnosis and emergency treatment due to vital risk, control of acute heart failure manifestations remission and proper monitoring. Differential diagnosis was focused on determining possible aspects like: acute heart failure (of various etiology), internal post-traumatic lesions or hemorrhages, tuberculosis polyserositis, collagenosis, nephrotic syndrome, protein deficiencies, neoplasia with hepatic determinations, hematological diseases (lymphomas, leukemias), considered in young patients. Severe visceral, vascular and tissular pathological alterations were reactively induced in a young person, by stasis and hypoperfusion due to hypodiastolic heart failure caused by persistent supraventricular tachyarrhythmia triggered post-traumatic, on a proarrhythmic structural heart.

Analysis of prognostic factors in colorectal carcinoma.

UNLABELLED: Colorectal cancer is one of the most common malignancies in development countries. The purpose of this study was to analyze the epidemiologic profiles of the disease, to examine the results of survival at five years after diagnosis and how it was influenced by pathological aspects. MATERIAL AND METHODS: In collaboration with Oncologic Clinic all colorectal cancer diagnosed from January 2002 to December 2006 were included in the study. Medical records of patients were retrieved and we note: age, residence, diagnosis date, grade, and stage and histology variables. Then were analyzed prognosis and survival at 5 years of patients related to these parameters. RESULTS: A total of 238 patients with colorectal cancer were identified. The average age at diagnosis was 63.3 years and more than half of cases were men (59%). By the end of the follow-up period 103 patients had died, 66.1% of them representing colon cancer. When analyzing the survival length according to tumor location at the end of the study, we found that are no significant differences between survivals in colic tumors compared to the rectum--53.9 months for right colon, 51.4 months for left colon and 49.5 months for rectum. The majority of tumors were grade II moderately-differentiated tumors 48.7% (116 of cases), and patients with grade I had the best survival, on average of 84.52 months. Tubular forms of colorectal cancer had the best percentage of five years survival (55.81%) being also the highest rate of survival (45.24% months). CONCLUSION: Factors that contribute to a favorable prognosis in colorectal cancer are tubular microscopic form, disease diagnosed in TNM stage I and II, GI and GII grading.