ABSTRACT Background: Bracket rebonding is a common problem in orthodontics which may result in many drawbacks. The aims of this study were to evaluate the effects of application of two enamel protective agents “Icon†and “ProSeal†on shear bond strength before and after rebonding of stainless steel orthodontic brackets using conventional orthodontic adhesive and to assess the site of bond failure. Materials and methods: Fifty sound extracted human upper first premolar teeth were selected and randomly divided into two equal groups; the first time bonding and the rebonding groups (n=30). Each group was subdivided into control, Icon and ProSeal subgroups. The enamel protective agents were applied after etching (preconditioners). Shear bond strength before and after rebonding of stainless steel brackets were assessed using the Universal testing machine and the adhesive remnant index was used to find out the bond failure site using a stereomicroscope. Then the results were statistically analyzed using one-way ANOVA analysis test and T-test. Results: There were no significant differences in the shear bond strength mean values in either group or their corresponding subgroups. Forty percentage of the bond failure in ProSeal groups occurred away from the enamel where 75% of those were at the enamel protective agents/adhesive interface. Conclusions: The application of Icon and ProSeal did not compromise the shear bond strength and the application of the ProSeal may protect the enamel surface from trauma (cracks, chipping or detachment).
In this paper, the dynamic of quark and anti-quark interaction has been used to study the production of photons in the annihilation process based on the theory of chromodynamic. The rate of the photon is to be calculated for charm and anti-strange interaction c→γg system with critical temperature 113 and 130 MeV and photon energy GeV/c. Here the critical temperature, strength coupling and photons energy are assumed to be affected dramatically on the rate of photons emission of state interaction c, which can form gluon possible structures and photon emission state. The decreased photons emission yields with increased strength couple of quarks reaction due to increase critical temperature from 113 MeV to 130 MeV were predicted. We
... Show MoreThe bacterial isolates were obtained from Al-Kindi Hospital were diagnosed by the Vitek-2 system and re confirm by 16srRNA gene as S. aurous, the results were shown 20 isolates (66.7%) out of 30 isolates were positive to protease production. All bacterial isolates (100%) were sensitive to Gentamicin and Levofloxacin. but resistant (100%) to aztreonam. The best temperature for enzyme production from bacteria was 37 °C, and the best pH for enzyme production was 7. Partial purification of the bacterial enzyme (protease) was carried out using short steps included ammonium sulfate 65% saturation, ion exchange using DEAE- cellulose column and then applied on gel filtration chromatography using Sephadex G-200 column. The enzymatic activit
... Show MoreNotwithstanding the importance of international cooperation as the other facet of international interactions, a strategy of conflict resolution, a maintainer of international peace and security, its provision in the United Nations conventions, as an objective of the United Nations after the international peace and security, however, the recognition of international cooperation has not been underlined by global, intellectual think tanks. While realism emphasized on the state's role in achieving international cooperation to ensure mutual and multilateral interests, liberalism focused on the role of international organizations in building such cooperation. Additionally, constructivist approaches developed other sub-variables to contribute to t
... Show MoreIn this paper a system is designed on an FPGA using a Nios II soft-core processor, to detect the colour of a specific surface and moving a robot arm accordingly. The surface being detected is bounded by a starting mark and an ending mark, to define the region of interest. The surface is also divided into sections as rows and columns and each section can have any colour. Such a system has so many uses like for example warehouses or even in stores where their storing areas can be divided to sections and each section is coloured and a robot arm collects objects from these sections according to the section’s colour also the robot arm can organize objects in sections according to the section’s colour.
HTH Ali Tarik Abdulwahid , Ahmed Dheyaa Al-Obaidi , Mustafa Najah Al-Obaidi, eNeurologicalSci, 2023
In many applications such as production, planning, the decision maker is important in optimizing an objective function that has fuzzy ratio two functions which can be handed using fuzzy fractional programming problem technique. A special class of optimization technique named fuzzy fractional programming problem is considered in this work when the coefficients of objective function are fuzzy. New ranking function is proposed and used to convert the data of the fuzzy fractional programming problem from fuzzy number to crisp number so that the shortcoming when treating the original fuzzy problem can be avoided. Here a novel ranking function approach of ordinary fuzzy numbers is adopted for ranking of triangular fuzzy numbers with simpler an
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