Background: The desire for an attractive appearing fixed orthodontic appliance fueled the use of ceramic brackets and clear accessories. Elastics are one of the most versatile materials available to orthodontists so studying their effect on the esthetic appearance is important. This an in vivo study, conducted to evaluate the effect of exposing stretched clear elastomeric ligatures to the oral environment from four different companies (OrthoTechnology, Morelli, Ortho Organizer, and Ormco). Materials and Methods: A total of 240 elastomeric modules were examined, 60 modules from each brand. Each of the 60 patients enrolled in the study, received 4 elastomeric modules on the 4 lower incisors, one from each brand. The specimens were placed on the teeth for 1, 2 and 4 weeks. After removal each module was kept in a sealed plastic bag and prepared for imaging and color measurement. Color measurements were made before and after use of the specimens. Images were taken by a cellular attachable microscope connected to a mobile phone with special J-cam program and the color change was calculated according to CIE Labcolor spaces system by the Adobe Photoshop program. The resulting data were statistically analyzed using ANOVA, LSD and Chi square tests. Results: The results showed that, all the elastomeric ligatures discolored after use. The discoloration increased with an increased incubation period in the mouth reaching the peak at 4 weeks interval and the yellowness index was the mostly effected color component. Elastomeric ligatures from Morelli brand were the most prone to discoloration, while Ortho Organizers and Ormco ligatures were the least prone to discoloration with the presence of large individual variation. Conclusion: It is necessary to alert the patient about the color changes that the clear ligatures experienced and the staining effect of certain foods. The orthodontist should select brands that are more resistant to color changes.
Background: Loss of tooth structure may be due to tooth to tooth contact and presence of abrasive components in the work environment. The aim of study was planned to evaluate the occurrence of dental attrition among Cement factory workers. Material and Method: The Sample included all workers chronically exposed to cement dust in the EL-Kubaisa cement factory (95 workers). A comparative group of workers (97) were non-exposed to cement dust was selected. All workers were males in gender with age range (25-55) years. The assessment of tooth wear was based on the criteria of smith and knight, 1984. Results: The maximum tooth wear score for exposed workers was 84.2% while non exposed workers was 38.1%,with statistical differences between two g
... Show MoreThe inhibitory behavior of L-Cysteine (Cys) and its derivatives towards iron corrosion through density functional theory (DFT) was investigated. The current research study undertakes a rigorous evaluation of global as well as local reactivity descriptors of the Cys in protonated as well as neutral forms and the changes in reactivity after the combination of Cys into di- and tripeptides. The inhibitory effect of di- and tri-peptides increases since, in the molecular structure, the number of reaction centers increase. We computed the adsorption energies (Eads) and low energy complexes with most stability for the adsorption of small peptides and Cys amino acids onto the surfaces of Fe (1 1 1). We found that the adsorption of tri-peptides onto
... Show MoreThis study includes adding chemicals to gypseous soil to improve its collapse characteristics. The collapse behavior of gypseous soil brought from the north of Iraq (Salah El-Deen governorate) with a gypsum content of 59% was investigated using five types of additions (cement dust, powder sodium meta-silicate, powder activated carbon, sodium silicate solution, and granular activated carbon). The soil was mixed by weight with cement dust (10, 20, and 30%), powder sodium meta-silicate (6%), powder activated carbon (10%), sodium silicate solution (3, 6, and 9%), and granular activated carbon (5, 10, and 15%). The collapse potential is reduced by 86, 71, 43, 37, and 35% when 30% cement dust, 6% powder sodium meta-silicate, 10% powder activated
... Show MoreThe topic of this research deals with an analytical study of the nature of the visual sent by the sculptural monument of the person of Christ around the world, the nature of this monument, the manner of its embodiment, the mechanism of reception for each of the societies that this monument addressed to them, how it was reflected on them, how it was reflected on them, and whether these works are related to their culture or not, I discussed this study All this, and the researcher has established theoretical research axes for the research according to the desired goal of this study, which is the definition of the mechanism of visual discourse of statues of Christ around the world and were as follows: (The first axis: the discourse and visua
... Show MoreThe Sacrament of Marriage in the Christian Religion
The study aims to identify the colleges women in the USA where he was browsing the Internet for five universities and sixty-two women's college located these colleges in 25 states only three general and other civil 51% supported by the churches and religious associations of various began its founding in Alqrnn eighteenth and continued in the nineteenth and twentieth and to provide an opportunity for women to complete higher education, while most men's colleges opened their doors to the admission of women and turned it on coeducation
The sacred totem is one of the social phenomena that occupied the ideas of researchers, and took up a wide area of their research, and it is one of those phenomena that emerged from one of the translations of the Tabu; Who took a psychological and anthropological analysis Because it is one of the social practices, and the main focus of it is the human group and its source is religion. Therefore, this research came with demands, the first of which is to give a semantic concept of the Tommy sanctuary, and then the analytical aspect by standing on the sacred things in the Qur’anic text that God Almighty sanctified, and the third requirement is to examine what people have sanctified, as an analysis of the verses that have
... Show MoreBackground: Lymphomas are group of diseases caused by malignant lymphocytes that accumulate in lymph nodes and caused the characteristics lymphadenopathy. Occasionally, they may spill over into blood or infiltrate organs outside the lymphoid tissue. The major subdivision of lymphomas is into Hodgkin lymphoma and non–Hodgkin lymphoma and this is based on the histologic presence of Reed-Sternberg cells in Hodgkin lymphoma. Salivary immunoglobulin A is the prominent immunoglobulin and is considered to be the main specific defense mechanism in oral cavity. The aim of this study was to determine the level of salivary immunoglobulin A in lymphoma patients before and after chemotherapy treatment. Subjects, materials and methods: The study i
... Show MoreThe research aims to enhance the level of evaluation of the performance of banking transactions control policies and procedures. The research is based on the following hypothesis: efficient transactions control policies and procedures contribute enhancing financial reporting, by assessing non-application gap of those policies and procedures in a manner that helps to prevent, discover, and correct material misstatements. The researchers designed an examination list that includes the control policies and procedures related to the transactions, as a guide to the bank audit program prepared by the Federal Financial Supervision Bureau. The research methodology is
... Show MoreBackground: The present in-vitro study was undertaken to evaluate and compare fracture resistance of weakened endodontically treated premolars with class II MOD cavities restored with different bulk fill composite restorations (EverX posterior, Alert, Tetric EvoCeram Bulk Fill, and SDR). The type and mode of fracture were also assessed for all the experimental groups. Materials and Method: Forty-eight human adult maxillary premolar teeth were selected for this study. Standardized extensive class II MOD cavities with endodontic treatment were prepared for all teeth, except those that were saved as intact control. The teeth were divided into six groups of eight teeth each (n=8): (Group 1) intact control group, (Group 2) unrestored teeth with
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