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 (precondi

We claim that a proper subact Ṅ have been compactly packed (c.P) in generalization idea of c.P modules to S Acts. whether for all family of prime subact {Pα}(α∈λ) for some β∈λ Pβ ⊇ Ṅ when ∪(α∈λ)Pα, ⊇ N. We refer to an S-Act Ṁ as c.P. if every subact is compactly packed. We study various properties of c.P S-Acts.

This study evaluated the extent to which obturation materials bypass fractured endodontic instruments positioned in the middle and apical thirds of severely curved simulated root canals using different obturation techniques. Sixty resin blocks with simulated root canals were used, each with a 50° curvature, a 6.5 mm radius of curvature, and a length of 16.5 mm, prepared to an ISO #15 diameter and taper. Canals were shaped using ProTaper Universal files (Dentsply Maillefer) attached to an X-smart Plus endo motor (Dentsply), set at 3.5 Ncm torque and 250 rpm, up to size S2 at working length. To simulate fractures, F2 and F3 files were weakened 3 mm from the tip, then twisted to break in the apical and middle sections of the canal, re

Background: 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

The study aims to build a proposed training program for school leaders in the Sultanate of Oman on the planning practices of the Kaufman model in light of the needs and challenges of reality. It also aims to identify the challenges facing school leaders in practicing the stages of strategic planning. To achieve these objectives, the study adopted the descriptive approach due to its suitability to the nature of the study. A questionnaire was used to collect the needed data. The study sample included (225) individuals from school principals, their assistants and senior teachers in post-basic education in the Sultanate of Oman. After processing the data statistically, the study concluded that the reality of planning practices for school lea

This study aims at describing the identity crisis of Diaspora people (Arab -American) in "Laila Halaby's" novel "Once in A promise Land". Halaby tackles the issues of racism, exclusion, and instability of identity that affect the Arab American community after the terrorist event of eleventh of September. She sheds light on the experiences of her significant characters Salwa and Jassim in America, clarifying how this event weakened their social position and turns their presence in America questionable. "Halaby" describes the bitterness of her characters who are induced into a dream of belonging to a land that transcends their original culture and religious values as well as their language. "Halaby" explains the subsistence in America involvi

A simple, rapid and sensitive spectrophotometric method has been proposed for the determination of La (III) using 3-hydroxy -4-(2-hydroxy-phenyl azo) naphthalene -1- sulfonic acid as a chromogenic reagent. This method is based on the formation of a red-pink colored complex, upon the reaction of La(III) with the reagent in an alkaline medium (pH= 9.50), having a maximum absorbance at 459 nm. Beer's law is valid in the concentration range 0.512 µg.ml-1 with a Sandell's sensitivity value of 0.0188 µg.cm-2 and molar absorptivity of 7376.12 L.mol-1.cm-1. The stoichiometric composition of the chelate is 1:3. The effect of the presence of different cations as interferants in the determination of La(III) under the given optimum conditions wer

عُـدّت الحُدود الأمريكيَّة ـــــ الكنديَّة بأنَّها أطول حدود في العالم بين دولتين، إذ بلغت (8891 كم)، وهذا الجوار الجغرافي ألزم البلدين بإقامة علاقات تعاون وتكامُـل عِبرَ تاريخ البلدين، ولذلك تـنـوَّعـت تِلكَ العلاقات ولا سِيَّما الاِقتصاديَّة والتَّعاون العسكري وما آلَ إليه من تأسيس حلف الشمال الأطلسي (الناتو), واشتراكها في الحرب الكوريَّة, فضلاً عن ذلك مسارات التَّعاون التجاري ومنح التسهيلات اللَّازِمة ل

خضع فن التمثيل وتقنياته في العصر الحديث لانعطافات عديدة ومختلفة وجوهرية في بنيته العامة والخاصة لاسيما وان المنظرين والمخرجين والممثلين المحدثين على تماس وعلى حراك في خلق حساسية أدائية جديدة تنسجم ولغة العصر وحاجاته وإشكاله وأنماطه منطلقين في تنظير اتهم وتطبيقاتهم من نظم والسلوك البشري الخارجي والداخلي والاستفادة من ميادين الفنون الأدائية الأخرى كالرقص وفن البهلوان والمهرج والسيرك فضلا"عن استعارته الخ