Background: White spot lesion is the first visible sign of dental caries that is characterized by demineralized lesion underneath an intact surface. Several studies demonstrated that they could be treated using noninvasive techniques like the use of fluoride or casein phospho-peptide and amorphous calcium phosphate. Improvement in aesthetic outcomes by covering the demineralized enamel is one of the advantages of the use of resin infiltration and opal-ustre microabrasion, which are two new techniques that had been used for treatment of white spot lesion. The purpose of this study was to evaluate the impact of resin infiltration and microabrasion in the microhardness of the artificial white spot lesions at various depths. Material and method: Forty-eight artificially white spot lesions were divided into three groups (n=16) according to the depth of the lesion (shallow enamel, deep enamel, shallow dentine). Then, each of the main groups was divided into two subgroups (n = 8), the first group was treated with resin infiltration, while the second one was treated with Opalustre microabrasion. Assessment of the microhardness was done using Vickers hardness at the baseline, after demineralization (formation of the white spot lesion) and after the treatment with the resin infiltration and the microabrasion. Results: There was a significant difference in the microhardness of all the layers after demineralization. Although the hardness values that found among the icon group in the inner enamel and the outer dentine were higher than that of the opalustre, statistically there was no significant difference between the two mate-rials in all the layers of the white spot lesion. Conclusion: Microhardness values decrease as the depth of the white spot lesion increase. There was an increase in the microhardness values after the treatment with the resin infiltration and the microabrasion.
The purpose of this work was to study the effects of the Nd:YAG laser on exposed dentinal
tubules of human extracted teeth using a scanning electron microscope (SEM). Eighty 2.5mm-thick
slices were cut at the cementoenamel junction from 20 extracted human teeth with an electric saw. A
diamond bur was used to remove the cementum layer to expose the dentinal tubules. Each slice was
sectioned into four equal quadrants and the specimens were randomly divided into four groups (A to D ).
Groups B to D were lased for 2 mins using an Nd:YAG laser at 6 pulses per second at energy outputs of
80 , 100 and 120 mJ. Group A served as control. Under SEM observation, nonlased specimens showed
numerous exposed dentinal tubules. SEM o
Strategy Descrtibes How an Organization Matches its own Capabilites With Opportunities in Environment , in Order to Accomplish its Overall Objectives , So That The Organization is Considering Responding to Challenges by Adopting one or More of Strategies, Like Differentioning its Product, or Achieving Cost Leadership.
The Key Role of Management Accountant is to Evlaute The Successful it Has Been in Implementing Organization Strategy.
This Research Target to Explain The Key Role of Management Accountant in Evaluate of Organization Strategy. by Strategic Analysis of Operating Income From Specific Sources Such as Cost Savings and Growth in Stead of Emphasizing Only The Aggrega
... Show MoreBackground: Irrigation of the canal system permits removal of residual tissue in the canal anatomy that cannot be reached by instrumentation of the main canals so the aim of this study was to compare and evaluate the efficiency of conventional irrigation system, endoactivator sonic irrigation system,P5 Newtron Satelec passive ultrasonic irrigation and Endovac irrigation system in removing of dentin debris at three levels of root canals and to compare the percentage of dentin debris among the three levels for each irrigation system. Materials and methods: Forty extracted premolars with approximately straight single root canals were randomly distributed into 4 tested groups of 10 teeth each. All canals were prepared with Protaper Universal ha
... Show MoreIn this study, Epoxy Resin plates was prepared by mixing epoxy(A) and hardner(B)with ratio(A:B) (3:1) with different thickness (0.3-0.96)cm. The effect of thickness on optical properties have been studied (absorption ,transmission ,reflectance) also the optical constant were found like (absorption coefficient, extenuation coefficient and refraction index) for all of the prepared plates. The results have shown that by increasing the thickness of plates., the absorption intensity increase in which at plates thickness (0.3-0.96)cm the absorption intensity were(1.54-1.43) respectively, and since absorption peak for epoxy occur in ultraviolet region and exactly at wavelength(368)nm and energy gap(Eg=3.05 eV) thus their good transmittance in the
... Show MoreFrictional resistance occurs whenever sliding happens, negatively impacting treatment outcomes and duration. It is a clinical challenge and must be dealt with efficiently to achieve the best orthodontic results. Aims of this study: compare and evaluate the static frictional forces under the wet condition to mimic the oral environment produced by using a polycrystalline ceramic bracket, monocrystalline ceramic bracket, 0.014 of an inch nickel-titanium (Rhodium coated archwires, and ilusio aesthetic archwires), and 0.019 x 0.025 of an inch stainless steel (Rhodium coated archwires, and ilusio aesthetic archwires). Ninety-six aesthetic brackets (48 monocrystalline and 48 polycrystalline brackets) were used and stored in different incub
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The research aims to build an integrated frame of knowledge for the basic research topics, represented by (assimilation of knowledge, strategic clarity) and their basic variables, by examining the most important scientific propositions on these topics in administrative thought, and framing the knowledge contained in them, in a serious attempt to provide appropriate answers to questions The research dilemma, and the research was applied in the Iraqi Airways Company, whose number is (1200) employees, and the descriptive and analytical approach was adopted in conducting the research. A valid form for statistical analysis, i.e., with a retrieval rate of (92%). The two researchers used the (SPSS & AMOS) program for
... Show MoreAn experimental study is carried out on the effect of vortex generators (Circular and square) on the flow and heat transfer at variable locations at (X = 0.5, 1.5, 2.5 cm) ahead of a heat exchanger with Reynolds number ranging from 62000< Re < 125000 and heat flux from 3000 ≤ q ≤ 8000 W/m2 .
In the experimental investigation, an apparatus is set up to measure the velocity and temperatures around the heat exchanger.
The results show that there is an effect for using vortex generators on heat transfer. Also, heat transfer depends on the shape and location. The circular is found t
... Show MoreThis study aimed to evaluate the anticancer activity and cell division arresting by dandelion methanolic extract on breast cancer cell line MCF-7 cancer cell line. For achieving this goal, cytotoxicity assay (MTT assay), multipara system assay: High Content Screening (HCS) which include (viable cell count VCC; membrane permeability MP; cellular mitochondrial permeability CMP; nuclear intensity NI and cytochrome C releasing ), reactive oxygen species detection and cell cycle phases division were tested. The results of this study showed the ability of the plant to reduce cancer cell viability in a dose-dependant manner within IC50 (141.0) in comparison to IC50 of (334.4) on the
... Show MoreAlthough several drugs are used against Leishmania infection but they are associated with several adverse complications. Therefore, a new effective treatment needed to be found. In this study, the effect of carbonnanotubes nanoparticles (CNTs NPs) on Leishmania donovani promastigotes was assessed. Viability of promastigotes after adding different concentrations of carbonnanotubes (CNTs) nanoparticles (0.05, 0.1, 5, 10, 20, 40, 60 and 80 μg/ml) to the parasite culture was evaluated by growth rate, viability rate assay and morphological changes. The results indicated that the effect of CNTs NPs on growth rate of promastigotes form. After exposed to 80 μg/ml of CNTs, the growth rate of promastigotes clearly decreased compared with promast
... Show MoreLeishmaniasis is a widespread parasitic disease caused by Leishmania parasite, this disease considers a major health problem among worldwide. Treatments available are expensive or with cytotoxic side effect. This study was aimed to investigate the effect of an herbal new compound, called artemisinin, derived from a Chinese plant called Artemisia annua. Various concentrations were studied in vitro against L. tropica amastigotes by chamber counting to investigate its effect on the proliferation of promastigotes. Three incubation periods were adopted (24, 48, 72) hours. The results showed a significant decrease in surviving promastigotes, in parallel with the normal parasite count of untreated promastigotes, along the periods studied. This stu
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