Testing the sensitivity of periodontal pathogens requires the selection of an easier and more reliable method to be used with such anaerobic bacteria that need a long period of time for growth. Natural materials are a new era of antibacterial agents to control periodontal infections. The aims of the current study were to test the antibacterial activity of two natural agents, namely olibanum and alum, against three types of red complex periodontal pathogens and compare the application of agar diffusion and microdilution methods for testing the susceptibility. Gingival crevicular fluid from pockets with chronic infections was sampled as a source for the three types of bacteria, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola (the red complex pathogens). The samples (n= 30) were cultured on three types of media, namely Schaedler Anaerobe Agar, Tannerella forsythia (TF) agar, and Trypton Yeast extract Gelatin Volatile fatty acids and Serum (TYGVS) agar for the three types of red complex pathogens. After anaerobic growth, the isolates of red complex pathogens were identified by cultural and cellular morphological characteristics and confirmed by molecular diagnosis. The antibacterial activity of the two natural materials was tested by agar (disk and well) diffusion and microdilution method (spectrophotometer- and resazurin- based). Ciprofloxacin (CIP) and chlorhexidine (CHX) were used as controls. Minimal Inhibitory Concentrations (MICs) of the four reagents (olibanum, alum, CIP, and CHX) were determined on the three types of bacteria. MIC values by each susceptibility method were compared and analyzed statistically at p- value ≤ 0.05. The results showed that resazurin- based microdilution method was the easiest and simplest approach which gave reliable reads. MIC values of the four regents differed from a method to another and from one bacterium to another. Statistically, there were no significant values among these differences, except for olibanum which was statistically more significant than the other reagents.
Background: Poly-ether-ether-ketone(PEEK) has been introduced to many dental fields. Recently it was tested as a retainer wire‎ following orthodontic treatment. This study aimed to investigate the effect of changing the bonding spot size and location on the performance of PEEK retainer wires. Methods: A biomechanical study involving four three-dimensional finite element models was performed. The basic model was with a 0.8 mm cylindrical cross-section PEEK wire, bonded at the center of the lingual surface of the mandibular incisors with 4 mm in diameter composite spots. Two other models were designed with 3 mm and 5 mm composite sizes. The last model was created with the composite bonding spot of the canine away from the center of t
... Show MoreFor a finite group G, the intersection graph of G is the graph whose vertex set is the set of all proper non-trivial subgroups of G, where two distinct vertices are adjacent if their intersection is a non-trivial subgroup of G. In this article, we investigate the detour index, eccentric connectivity, and total eccentricity polynomials of the intersection graph of subgroups of the dihedral group for distinct primes . We also find the mean distance of the graph .
This research studyies the effect of MgO and ZrO2 as additives in sintering Al2O3 . The experimental results are modeled using ( L2 _ regression) technique , sintered density and grain size rate measurments were accounted by utilizing experimental results of undoped , MgO doped and ZrO2 doped alumina impregrated with spherical large pores in final stage of sintering . The effect of each additive is inhibitian of the grain growth and increasing the densification rate which enhances the kinietics of densification and the removal of large and small pores.
This research presents the kinetics of the saponification reaction using mixed fats of olein and stearin [in the ratio (3:1)] with NaOH solution. In this reaction, excess solution of NaOH was used to ensure the reaction being irreversible. Three parameters were varied to show their effects on the reaction rate .They are: percentage excess of NaOH solution (10 % - 100 %) , temperature (100-150)oC , and stirring speed (400-1100) rpm. It was noticed that increasing the percentage excess of NaOH solution enhances the rate of reaction while increasing temperature decreases the reaction rate since it is exothermic reaction. Increasing stirring speed also improves the reaction rate because it is mass transfer controlled .Calcu
... Show MoreThe research aims to verify that there is an influence between innovative marketing and the organization's reputation by brand mediation.
The research problem is that the Oil Marketing Company (SOMO) needs innovative, unconventional methods in marketing its products and improving its reputation by adopting a solid brand that adds value to the product.
The importance of the research: The importance of the research is highlighted as it deals with essential variables in business organizations that help increase customer loyalty by adopting a distinctive brand.
The research started from four main hypotheses to explore correlations and influence between researc
... Show MoreGovernance system extends its application to include all internal bodies in the banking institution as well as the external authorities that impose the application of the rules of banking governance, each according to its position.
Among the external actors involved in applying the rules of banking governance is the central bank that takes the position of the general supervisor of all banking activities in the country, and that the central bank exercises its supervision and control over banks through the compliance monitor, and the latter is the effective link between the central bank and the banks under its supervision. Therefore, we find that it has an important role in implementing the rules of banking governance at the level
... Show MoreThere are certain dates in the history of nations that have their effects on them ,and the 25th of January 2011 is considered one of them in the history of the state of Egypt .Since this date Egypt has passed through many events that led to changes in the political life and its actors . New rolls has arisen for actors that didn't take part in the political life before so clearly ,like the military establishment which started to practice more prominent political roll, till it became the most important actor in the political life of Egypt .This establishment tried to institutionalize its roll through constitutional means ,considering that controlling the authority is the only alternative to safeguard the state which we are trying to study
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