Do ozone and boric acid affect microleakage in class V composite restorations?

The aim of this in vitro study was to evaluate the effects of chlorhexidine gluconate (2%), sodium hypochloride (2.5%), ozone gas, and boric acid at different concentrations (1%, 3%, 5%, and 7%) on microleakage from composite restorations.

In a total of 80 extracted human canine teeth, a class V cavity was opened on the buccal surface and the samples were separated into eight groups. In the control group, no procedure was applied for cavity disinfection, then composite restoration (Z250, 3M) was made using single-stage, self-etch adhesive (Single Bond 3M). In the other groups, seven different disinfectants were used, then the cavity was restored. The teeth were split into two in the buccolingual direction, parallel to the long axes. Stain penetration was examined under stereomicroscope and scored. Examination with SEM was made on one sample from each group, selected at random. Statistical evaluations were made using Dunnett C Post Hoc Comparison and Kruskal–Wallis H tests.

In the occlusal region evaluation, the groups with the lowest level of leakage were the 3% and 5% boric acid groups, and the highest levels of microleakage were determined in the chlorhexidine group and the 1% boric acid group. In the gingival region, the lowest level of microleakage was in the 5% boric acid group and the highest levels were determined in the 1% and 7% boric acid groups.

Boric acid disinfectants used at suitable concentrations were not seen to create a risk in respect of microleakage.     

Effect of Different Restorative Materials on Microleakage of Ozone Gas and Traditional Cavity Disinfectant Applied Teeth

The aim of this in vitro study is to investigate the effects of ozone and conventional cavity disinfectant on microleakage at the cavities which are restorated with different restorative materials. Ninety human molar teeth were used in this study. Black V cavities are prepared on buccal surfaces of teeth. Teeth are divided to 3 groups which contains 30 teeth. Group 1: ozone applied; Group 2: 2% chlorhexidine applied; Group 3: any disinfectant is not applied. And then all groups are divided to three subgroups. All subgroups are restored with silorane, ormocer, and traditional composite according to the manufacturer’s directions. Sections were examined under a microscope. Occlusal and gingival microleakage values by a separate researcher and scores were recorded. Statistically results were reviewed with ANOVA and Kruskal–Wallis Tests. Statistically significant difference of microleakage between cavity disinfectant and control groups’ occlusal and gingival lines was not found (p > 0.05). There was no differences at occlusal lines of composite subgroups (p > 0.05) but also significant difference at gingival lines was found (p < 0.05). Statistically significant difference was found among the composite materials, between chlorhexidine and control groups’ gingival lines. The most successful results at gingival lines were found with silorane.     

Four‐band electromagnetic energy harvesting with a dual‐layer metamaterial structure

A four‐band metamaterial harvester for harvesting 0.9 GHz, 1.8 GHz, 2.6 GHz, and 5.8 GHz signals is proposed by a dual‐layer structure. 0.9 GHz and 1.8 GHz bands are harvested by the resistors in front layer, whereas harvesting of 2.6 GHz is achieved by the resistors in second layer. All resistors in front and back layer contribute to harvesting at 5.8 GHz. Numerical calculations are verified by two different full‐wave electromagnetic solvers based on finite‐integration and finite‐element techniques. Power dissipation ratios at 0.9 GHz, 1.8 GHz, 2.6 GHz and 5.8 GHz frequencies concentrated at the resistors are found as 82.3%, 82.8%, 74.6%, and 83.6%, respectively, by the finite‐integration‐based solver. Besides, the finite‐element method‐based solver results in harvesting efficiencies of 79.6%, 93.4%, 73.7%, and 93.8%. The efficiency of the harvester is investigated for different oblique incidences. The proposed metamaterial harvester can be a good candidate for multi‐band absorption and harvesting applications.     

Binary crow search algorithm for the uncapacitated facility location problem

Neural Computing and Applications - The crow search algorithm (CSA) is a recently proposed population-based optimization algorithm for continuous optimization. Since the original CSA searches for a...     

Dual‐Band Double‐Cylindrical‐Ring 3D Frequency Selective Surface

This study presents a dual‐band 3D frequency selective surface that provides a large degree of freedom in frequency and bandwidth adjustability. The proposed structure is evaluated in terms of its structural parameters, and prototypes are fabricated. The radius of the copper rings and the height of the cylinders are considered, and are shown through full‐wave electromagnetic simulations to have a significant effect on the frequency characteristics of the frequency selective surface. The measurement results of the fabricated samples are compared with the simulation results, and a satisfactory agreement is obtained.     

Invariant solutions and conservation laws to nonconservative FP equation

We generate conservation laws for the one dimensional nonconservative Fokker–Planck (FP) equation, also known as the Kolmogorov forward equation, which describes the time evolution of the probability density function of position and velocity of a particle, and associate these, where possible, with Lie symmetry group generators. We determine the conserved vectors by a composite variational principle and then check if the condition for which symmetries associate with the conservation law is satisfied. As the Fokker–Planck equation is evolution type, no recourse to a Lagrangian formulation is made. Moreover, we obtain invariant solutions for the FP equation via potential symmetries.     

Antibacterial Activities of the Extracts of Some Herbs Used in Turkish Herby Cheese Against Listeria Monocytogenes Serovars

In this study, antimicrobial activities of the four different extracts (in methanol, ethanol, n‐hexane and water) of some herbs including Allium vineale, Chaerophyllum macropodum , and Prangos ferulacea were investigated against Listeria monocytogenes serovars 1/2b, 4b, and 4ab. For many centuries, these herbs were used in food production in Turkey. While water extracts of all the plants did not show any antibacterial activity, the other extracts of these plants showed variable degrees of antibacterial activity against L. monocytogenes serovars tested. The extracts of Allium vineale showed higher antibacterial activity than the other plants. The methanol extracts of all the plants exhibited higher activity than the ethanol and n-hexane extracts. L. monocytogenes 4ab was the most sensitive serovar to extracts of these plants. The results indicated that the methanol and ethanol extracts of these plants displayed remarkable activity against L. monocytogenes serovars and therefore, they could be used as natural anti-Listeria monocytogenes additives in herby cheese.     

A comparative path establishment study on routing performance of MLR WDM optical networks

In this paper, we investigate the effect of path establishment method priorities over routing performance in mixed line rate (MLR) wavelength division multiplexed (WDM) optical networks. The survivable routing with rate and wavelength assignment (SRRWA) problem is presented and an efficient shared backup path protection solution is proposed. We prepared detailed simulation scenarios with all possible prioritizations and observed their performances. The simulation results show that assigning higher priority to single hop methods as compared with multi‐hop methods yields better performance. In both methods, it has been observed that assigning higher priority to grooming reduces the communication cost and the traffic blocking ratio while enhancing the resource utilization.     

The fate of two Listeria monocytogenes serotypes in "cig kofte" at different storage temperatures

Cig kofte is a traditional Turkish food prepared from minced beef, bulgur, onions, garlic and varieties of spices. It is generally consumed within a few hours. However, leftovers can be kept in refrigerator or in room temperature up to 24h until they are consumed. In this study, survival and growth of two Listeria monocytogenes serotypes were investigated in cig kofte during the storage. For this purpose, the prepared samples were separately contaminated with serotypes 1/2b or 4b of L. monocytogenes at the level of 10(4)CFU/g and stored at 4°C and 21°C. L. monocytogenes colonies were counted at the beginning, 3rd, 6th, 12th and 24th hours of the storage. At 4°C, L. monocytogenes 4b significantly increased (P<0.05) from 4.12 to 5.49log(10)CFU/g but L. monocytogenes 1/2b remained constant (P>0.05) during the storage period. At 21°C, both L. monocytogenes 1/2b and 4b increased significantly (P<0.05) from 4.56 to 5.16log(10)CFU/g and from 4.23 to 5.65log(10)CFU/g, respectively. The physicochemical and microbiological characteristics of the cig kofte did not inhibit the growths of L. monocytogenes serotypes during the storage. These results indicated that L. monocytogenes was able to survive and grow in cig kofte at the both storage temperatures of 4°C and 21°C and cig kofte seemed to be a suitable medium for this pathogen.