Background This in vitro study compares a novel calcium-phosphate etchant paste to conventional 37% phosphoric acid gel for bonding metal and ceramic brackets by evaluating the shear bond strength, remnant adhesive and enamel damage following water storage, acid challenge and fatigue loading. Material and Methods Metal and ceramic brackets were bonded to 240 extracted human premolars using two enamel conditioning protocols: conventional 37% phosphoric acid (PA) gel (control), and an acidic calcium-phosphate (CaP) paste. The CaP paste was prepared from β-tricalcium phosphate and monocalcium phosphate monohydrate powders mixed with 37% phosphoric acid solution, and the resulting phase was confirmed using FTIR. The bonded premolars were exposed to four artificial ageing models to examine the shear bond strength (SBS), adhesive remnant index (ARI score), with stereomicroscopic evaluation of enamel damage. Results Metal and ceramic control subgroups yielded significantly higher (p < 0.05) SBS (17.1-31.8 MPa) than the CaP subgroups (11.4-23.8 MPa) post all artificial ageing protocols, coupled with higher ARI scores and evidence of enamel damage. In contrast, the CaP subgroups survived all artificial ageing tests by maintaining adequate SBS for clinical performance, with the advantages of leaving unblemished enamel surface and bracket failures at the enamel-adhesive interface. Conclusions Enamel conditioning with acidic CaP pastes attained adequate bond strengths with no or minimal adhesive residue and enamel damage, suggesting a suitable alternative to the conventional PA gel for orthodontic bonding.
In the ongoing series of our research, we prepared a new multifunctional azo-vanillin ligand (HL) and its Cu(II) complex to investigate their potential as versatile compounds for industrial/pharmaceutical purposes. Structural integrity was determined through spectroscopic analyses (FT-IR, NMR, Mass and UV-Vis), highlighting a distorted square planar geometry for the metal complex. The ligand was examined for its dyeing potential on wool and cotton with the latter showing better substantivity to cellulosic fibers and behaving as a good direct dye having excellent washing fastness. Furthermore, leveraging its surface-active properties, the ligand was tested as a green corrosion inhibitor for C-45 steel in a saline medium (3.5% NaCl) acr
... Show MoreSlurry infiltrated fibrous concrete (SIFCON) is a modern type of fibre reinforced concrete (FRC). It has unique properties; SIFCON is superior in compressive strength, flexural strength, tensile strength, impact resistance, energy absorption and ductility. Because of this superiority in these characteristics, SIFCON was qualified for applications of special structures, which require resisting sudden dynamic loads such as explosions and earthquakes. The main aim of this investigation is to determine the effect of fibre type on the apparent density of SIFCON and on performance under impact load. In this investigation, hook-end steel fibre and polyolefin fibre were used. Purely once and
The physician's commitment to medical insight is affected by several factors that vary from patient to patient in terms of the nature of the disease, the severity of the disease, the age of the patient, and the purpose of undergoing medical intervention. There are circumstances surrounding patients that require the physician to reduce the insight towards them, by concealing medical information. The physician must firmly commit to expanding the scope of his vision to a wider extent than in normal medical work. Therefore, we will discuss in this regard the cases in which medical explanation is reduced and the cases that require confirmation in the following order.
For the graph , the behavior associated with to the majority of the graphical properties of this graph is covered in this article. The reflection of the capabilities of on the Ly constructions is one of the key ideas addressed throughout this paper. For instance, by this technique we can comprehend the mechanism via which groups of relatively tiny structure are exist within Ly.
This paper deals with novels for group of Iraqi Women novelists published in the time period 2003 – 2013, and the functioning of temporal anomalies in the Iraqi Women's narrative.
In general, the novel contains structural elements such as: the characters, events and the places, these elements must be collected by an artist creating a complete work of fiction. However the time dominates the other elements through progression and regaining called Time paradox, it has a modern critical importance because of its impact in highlighting of political, social and cultural events that make up the fictional environment which cast a shadow over other techniques. And that it is clear in the course of the narrative.
The aim of the research is to reveal the reality of teacher performance evaluation in the Sultanate of Oman in light of some global models. The study followed a qualitative descriptive research design. Seven forms of teacher formative and summative assessments were analyzed. Besides, an analytical template was developed, consisting of six areas related to the teaching performance of teachers. These included: lesson planning and preparation, learning environment, education, professional development, student academic, and community and parental partnership. The study reached a number of results; the most notable is the lack of change of forms for more than a decade despite the rapid development of the educational system in the sultanate in
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