Background: Although bleaching is typically considered a safe procedure, various investigations have found minor negative effects and changes in mineral composition. The aim was to Evaluate and compare the efficacy of using Nanohydroxyapatite serum on surface microhardness of enamel surface before and after bleaching with chemically cured Boost bleaching. Material and methods: ten sound human permanent upper and lower premolar teeth were used and their roots were removed 2 mm apically to the cementoenamel junction, the crowns were sectioned mesiodistally into two halves buccal and lingual/palatal, the buccal surface was further subdivided into two halves. The samples were embeded in an acrylic resin, resulting in 30 specimens divided into 3 groups: Control group: using Boost bleaching and stored in artificial saliva for 14 days, prevention group: nanohydroxyaptite (n-HAP) serum applied 2-3 min once daily for 10 days followed by bleaching then stored for 14 days in artificial saliva and treatment group: in which bleaching used before nanohydroxyapatite serum and stored in artificial saliva for 14 days. The samples were subjected to a Vickers microhardness test measured at 4 times: base line, after nanohydroxyapatitem, after one day of bleaching and after storage in artificial saliva for 14 days in all groups. The data were analyzed statistically using repeated analysis of variance (ANOVA) test followed by Tukey's test. Results: there was a significant increase in microhardness in the prevention group (p<0.05) while there was no significant difference in microhardness readings in control and treatment groups (p> 0.05). Conclusion: n-HAP may enhance the microhardness of a bleached enamel surface when used as a preventive & treatment measure. Suggested that a higher increase in enamel microhardness occurs when n-HAP is used for 2-3 min once daily for 10 days before bleaching and maintaining this increase even after storage for 14 days in artificial saliva.
An image retrieval system is a computer system for browsing, looking and recovering pictures from a huge database of advanced pictures. The objective of Content-Based Image Retrieval (CBIR) methods is essentially to extract, from large (image) databases, a specified number of images similar in visual and semantic content to a so-called query image. The researchers were developing a new mechanism to retrieval systems which is mainly based on two procedures. The first procedure relies on extract the statistical feature of both original, traditional image by using the histogram and statistical characteristics (mean, standard deviation). The second procedure relies on the T-
... Show Moreالملخص ان حق الملكية هو الحق الاوسع نطاقا يمنح صاحبه صلاحية ممارسة السلطات كافة ويكون محل هذه السلطات كل ما يملك الشخص سواء كان شقه او طبقة اسوة بالعقارات الاخرى كدار للسكن او ارض ، ومن اهم هذه السلطات واوسعها نطاقا ( هو سلطة التصرف ). تعد هذه السلطة جوهر حق الملكية وأخطر السلطات الممنوحة للمالك كونه بواسطتها يمكنه الاستغناء عن ملكه بأي تصرف ناقل له كالبيع أو الهبة او الوصية مثلا ، ولأهمية هذه السلط
... Show MoreThe article considers the main reason for A. I. Herzen's address to obsolete words, which is their ability to acquire a stylistic coloring in the context of speech, as well as the possibility of combining, in some cases, with neutral lexemes of various functional styles. A certain stylistic effect of such characteristics of this type of vocabulary is represented, as a result of which their stylistic coloring in syntagmatic terms does not coincide with stylistic coloring in terms of paradigmatics, that is, in speech they have a completely stylistic meaning. Attention is focused on the role of outdated vocabulary, which consists in the fact that they serve to implement such features of the artistic style as imagery, emotionality, and their
... Show MoreAdministrative procedures in various organizations produce numerous crucial records and data. These
records and data are also used in other processes like customer relationship management and accounting
operations.It is incredibly challenging to use and extract valuable and meaningful information from these data
and records because they are frequently enormous and continuously growing in size and complexity.Data
mining is the act of sorting through large data sets to find patterns and relationships that might aid in the data
analysis process of resolving business issues. Using data mining techniques, enterprises can forecast future
trends and make better business decisions.The Apriori algorithm has bee
This paper adapted the neural network for the estimating of the direction of arrival (DOA). It uses an unsupervised adaptive neural network with GHA algorithm to extract the principal components that in turn, are used by Capon method to estimate the DOA, where by the PCA neural network we take signal subspace only and use it in Capon (i.e. we will ignore the noise subspace, and take the signal subspace only).
The category of those who agree with the phrase: The Environment and Life Program warns me of the environmental damages resulting from the issue of using black oil in electrical generators in residential neighborhoods came first, with a high rate of 81.4%. With the environment, the public always turns to the public broadcasting service and its programs to provide knowledge so that it can avoid it. Thus, the respondents' attitude towards this issue was positive.
The Costing Accounting is one the analytic tools which plays important role by support the management in planning& control and decisions-making ,as it became attendant necessity to establish any project whether industrial ,commercial ,service or agriculture ..etc.
The consolidated accounting system has committed the companies to have their active costing system in which the management can obtain their own data, but we found most of the economic units face problems of applying the costing system because of reasons related to the system design itself or might be related to the requirements of the application success.
... Show MoreThe downhole flow profiles of the wells with single production tubes and mixed flow from more than one layer can be complicated, making it challenging to obtain the average pressure of each layer independently. Production log data can be used to monitor the impacts of pressure depletion over time and to determine average pressure with the use of Selective Inflow Performance (SIP). The SIP technique provides a method of determining the steady state of inflow relationship for each individual layer. The well flows at different stabilized surface rates, and for each rate, a production log is run throughout the producing interval to record both downhole flow rates and flowing pressure. PVT data can be used to convert measured in-situ r
... Show MoreBackground: The access cavity is a critical stage in root canal therapy and it may influence the subsequent steps of the treatment. The new minimally invasive endodontic access cavity preparation concept aims to preserve sound tooth structure by conserving as much intact dentine as possible including the pulp chamber's roof, to keep the teeth from fracturing during and after endodontic treatment. While there is great interest in such access opening designs in numerous publications, still there is a lack of scientific evidence to support the application of such modern access cavity designs in clinical practice. This review aims to critically examine the literature on minimal access cavity preparations, explain the effect of minimally inva
... Show MoreThe downhole flow profiles of the wells with single production tubes and mixed flow from more than one layer can be complicated, making it challenging to obtain the average pressure of each layer independently. Production log data can be used to monitor the impacts of pressure depletion over time and to determine average pressure with the use of Selective Inflow Performance (SIP). The SIP technique provides a method of determining the steady state of inflow relationship for each individual layer. The well flows at different stabilized surface rates, and for each rate, a production log is run throughout the producing interval to record both downhole flow rates and flowing pressure. PVT data can be used to convert measured in-situ rates
... Show More