61 research outputs found

    Cementoblastoma of the Mandible: A Case Report and Review of Literature

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    Objectives Cementoblastoma is a rare benign odontogenic tumor which is linked to the root of a vital tooth. This tumor is usually accompanied by pain and swelling, and its most common site is the left mandibular first molar. General dentists’ inattention to oral lesions, especially tooth-related radiopacities, is problematic in some cases and results in delayed or missed diagnosis.Case Our patient was a 31-year-old woman who presented to our clinic complaining of dull pain in the left mandibular first molar. Root canal therapy was performed for the patient but the pain continued for the next 2 years. The patient was referred to a surgeon. Panoramic radiography revealed a radiopaque mass of approximately 2 x 1 cm in diameter attached to the root of the mandibular left first molar. The lesion together with the involved tooth was removed by excisional biopsy. Histopathological diagnosis was cementoblastoma.Conclusion Dentists’ knowledge of pulpal, periapical and periodontal lesions is usually satisfactory, but their inattention to oral lesions, especially tooth-related radiopaque lesions, is problematic in some cases. Pain from cementoblastoma may be mistaken for endodontic pain

    Optimizing Fenton-like process, homogeneous at neutral pH for ciprofloxacin degradation: Comparing RSM-CCD and ANN-GA

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    Author's accepted manuscriptAntibiotics are considered among the most non-biodegradable environmental contaminants due to their genetic resistance. Considering the importance of antibiotics removal, this study was aimed at multi-objective modeling and optimization of the Fenton-like process, homogeneous at initial circumneutral pH. Two main issues, including maximizing Ciprofloxacin (CIP) removal and minimizing sludge to iron ratio (SIR), were modeled by comparing central composite design (CCD) based on Response Surface Methodology (RSM) and hybrid Artificial Neural Network-Genetic Algorithm (ANN-GA). Results of simultaneous optimization using ethylene diamine tetraacetic acid (EDTA) revealed that at pH ≅ 7, optimal conditions for initial CIP concentration, Fe2+ concentration, [H2O2]/[Fe2+] molar ratio, initial EDTA concentration, and reaction time were 14.9 mg/L, 9.2 mM, 3.2, 0.6 mM, and 25 min, respectively. Under these optimal conditions, CIP removal and SIR were predicted at 85.2% and 2.24 (gr/M). In the next step, multilayer perceptron (MLP) and radial basis function (RBF) artificial neural networks (ANN) were developed to model CIP and SIR. It was concluded that ANN, especially multilayer perceptron (MLP-ANN) has a decent performance in predicting response values. Additionally, multi-objective optimization of the process was performed using Genetic Algorithm (GA) and Non-dominated Sorting Genetic Algorithm-II (NSGA-II) to maximize CIP removal efficiencies while minimizing SIR. NSGA-II optimization algorithm showed a reliable performance in the interaction between conflicting goals and yielded a better result than the GA algorithm. Finally, TOPSIS method with equal weights of the criteria was applied to choose the best alternative on the Pareto optimal solutions of the NSGA-II. Comparing the optimal values obtained by the multi-objective response surface optimization models (RSM-CCD) with the NSGA-II algorithm showed that the optimal variables in both models were close and, according to the absolute relative error criterion, possessed almost the same performance in the prediction of variables.acceptedVersio

    Effect of Beta Particles Spectrum on Absorbed Fraction in Internal Radiotherapy

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    Objective(s): The purpose of this research is to study the effect of beta spectrum on absorbed fraction ( ) and to find suitable analytical functions for beta spectrum absorbed fractions in spherical and ellipsoidal volumes with a uniform distribution for several radionuclides that are commonly used in nuclear medicine.Methods: In order to obtain the beta particle absorbed fraction, Monte Carlo simulations were performed by using the MCNPX code. The validation of the simulations was performed by calculating the absorbed fractions in spheres and comparing the results with the data published by other investigators. The absorbed fractions were calculated and compared by using an actual beta energy spectrum with those obtained through the mean beta energy of 14C, 199Au, 177Lu, 131I, 90Sr, 153Sm, 186Re, 32P, 90Y, 38Cl and 88Rb radionuclides.Results: The maximum difference between the absorbed fractions for beta particles accounting for the whole beta spectrum of all the considered nuclides was 29.62% with respect to the mean beta energy case. Suitable analytical relationships were found between the absorbed fraction and the generalized radius, and the dependence of the fitting parameters from beta spectrum energy was discussed and fitted by appropriate parametric functions.Conclusion: The results allowed the calculation of the absorbed fractions from the above stated beta sources uniformly distributed in spherical and ellipsoidal volumes of any ellipticity and volume, in a wide range of practical volumes that are not only used for internal dosimetry in nuclear medicine applications, but also in radiological protection estimates ofdoses from internal contamination

    Investigating the Level of Troponin I and its Association With Mortality in Patients With Sepsis, Severe Sepsis, and Septic Shock

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    Objectives: To investigate the level of troponin I and its association with mortality in patients with sepsis, severe sepsis, and septic shock. Materials and Methods: In general, 148 patients with sepsis, severe sepsis, and septic shock admitted to Kowsar hospital of Semnan in 2017-2019 were recruited in this study. Serum troponin levels were measured during the first 24 hours of admission. The second measurement was done in the next 48 hours, which aimed at increasing the likelihood of positive troponin over time. However, if the troponin was positive just once, the patient would be in the category of positive troponin. In addition, the patient’s prognosis was recorded within 30 days. Results: Based on the results, 27.7% had troponin levels higher than normal. The mortality rate in patients with normal and abnormal levels of troponin was 5.6% and 17.1%, respectively, which was a significant difference. The age of dead patients was significantly higher than the age of the living patients and the results showed that among the variables of gender, normal or abnormal level of troponin, age, and type of underlying infection, only age had a significant relationship with patients’ vital status. Conclusions: High levels of troponin were not effective in determining the prognosis of patients with sepsis, and only age had a significant relationship with patients’ vital status while the confirmation or rejection of this hypothesis will need further studies

    Insulin resistance surrogate markers and risk of hyperuricemia among patients with and without coronary artery disease: a cross-sectional study

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    BackgroundAlthough emerging evidence emphasizes the associations between both insulin resistance and hyperuricemia with coronary artery disease (CAD) risk, no definite relationship has yet been established. In this respect, time-efficient and affordable methods to estimate insulin resistance (IR) status, and to predict risk of hyperuricemia, are needed. Thus, the goal of this investigation was to examine the associations between IR, as assessed by novel surrogate markers [triglyceride-glucose (TyG) and TyG–body mass index (TyG-BMI)], and risk of hyperuricemia in patients with and without diagnosed CAD.MethodsThis cross-sectional study used data from the medical records of 1,170 patients who were referred to the cardiology outpatient clinic. Medical records, anthropometrics, and serum analytes were determined at the initial visit. Hyperuricemia was defined as serum uric acid ≥ 5.6 mg/dL. IR was estimated through surrogate markers (TyG and TyG-BMI). Multiple regression analysis was performed to assess the relationship between these indices and odds of hyperuricemia among patients with and without CAD.ResultsOverall, 814 angiographically-confirmed CAD cases (mean age (SD) = 52 (8)yrs) were compared with 356 patients without CAD (mean age (SD) = 48 (8)yr). There were positive associations between TyG and TyG-BMI indices and odds of hyperuricemia in CAD patients after controlling for confounders (adjusted odds ratio (aOR) = 1.60; 95%CI: 1.02–2.51; p-value = 0.036; and aOR = 1.83; 95%CI: 1.24–2.70; p-value = 0.002, third tertiles for TYG and TYG-BMI, respectively).ConclusionThe present findings suggest that higher levels of the IR surrogate markers, TyG and TyG-BMI, are associated with higher odds of hyperuricemia in patients with CAD. However, given the cross-sectional design of this study, the sensitivity and specificity of these novel markers could not be determined for confirming the diagnosis of IR and hyperuricemia, further studies are needed to determine such outcomes and to confirm the current findings

    Microleakage comparison of resin modified glass ionomer and OrthoMTA used as a coronal barrier in nonvital teeth bleaching

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    Background and Aim: Common causes of dental discoloration include trauma, drugs, genetic defects, decay, and age. In order to correct discoloration of pulpless teeth, internal bleaching is recommended. The aim of this study was to compare microleakage of resin modified glass ionomer and OrthoMTA used as an intraorifice barrier in non-vital bleaching. Methods: In this experimental study, 36 extracted mandibular premolars were selected and randomly divided into two experimental (n = 16) and two control groups (n = 2). 2mm of OrthoMTA and RMGI cements were placed as intraorifice barriers in the experimental groups. Subsequently, we placed a mixture of sodium perborate and 30% hydrogen peroxide as internal bleaching material into the canal and replaced it every three days. Leakage was measured using pH diffusion method by a digital PH meter. Data were statistically analyzed by using T- independent test and repeated measures and variance analysis (P<0.05). Results: The pH value of the negative control group was as same as the PH of normal saline while the PH value of positive control group was significantly higher than those of other groups. PH values of Ortho MTA and RMGI at the baseline and on the first, sixth and ninth day did not show significant differences with one another, while microleakage of OrthoMTA group was significantly lower on the third day. Conclusions: In general, OrthoMTA had less leakage than RMGI but both materials can be used as suitable barriers for internal tooth bleaching Keywords: Tooth bleaching, OrthoMTA, Glass ionomer, leakag

    A Comparative Investigation of the Microleakage of Biodentine and Mineral Trioxide Aggregate as Coronal Barrier in Nonvital Bleaching

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    Background: Internal bleaching is recommended to correct the discoloration of pulpless teeth. This study aimed to compare the microleakage of biodentine and mineral trioxide aggregate (MTA) used as an intracanal barrier in non-vital bleaching. Methods: An experimental study was performed in which 36 extracted mandibular premolars were randomly divided into two experimental groups (n= 16) and two control groups (n= 2). In experimental groups, 2mm of OrthoMTA and biodentine cement were placed as intracanal barriers. The control groups were prepared similar to experimental groups, except that in positive control group the orifice barrier material was not used and in negative control group the whole root surface was covered with nail polish and orifice barrier material was not used. Subsequently a mixture containing sodium perborate and 30% hydrogen peroxide was placed into the pulp chambers and replaced every three days. Microleakage was measured using a pH diffusion method by digital pH meter. pH was checked before placement and at days 1, 3, 6, and 9 after placement. Data analysis was done in SPSS V24 Results: The pH value in negative control group was similar to that in normal saline group, while the pH value in positive control group was found to be significantly higher than other groups (P< 0.05). Nosignificant differences were seen in pH values between the experimental groups at baseline and days 1 and 6, but pH values of biodentine were significantly higher than orthoMTA at days 3 and 9 (P< 0.05). Conclusions: MTA can be used as an efficient orifice barrier during internal bleaching, specifically in cases where there is probability for cervical root resorption. Keywords: tooth bleaching, mineral trioxide aggregate, dental leakag
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