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.
Aннотация
В статье представлены явления полисемии и омонимии в специализированной терминосистеме, а именно в геодезической терминологии; определены предпосылки и причины возникновения полисемии и омонимии в профессиональном языке в области геодезии и кадастра; установлены различия и взаимосвязь между понятиями омонимия и полисемия; выделены главных типы полисемантических тер
... Show MoreThe research addresses the questioning of political loads in a cinematic model from the films of the author (David Abdel Sayed), who has been busy throughout his films in criticizing political power, where he presented protests visions her body the artistic composition of cinematic means of expression through artistic treatments that facilitate the representations of modernity in contemporary cinematic trends, and by this Several contemporary cinematic criticism is an example of a thinker cinematographer who presents his critical thesis on power politics through the composition of the film (material - form - expression). The research consisted of four chapters. The first was a methodological framework that included the research problem o
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Provision is guaranteed for all people if moral and material causes have been considered.
Key Words:
Purports – Educational – Co
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The most famous thing a person does is talk. He loves and hates, and continues with it confirming relationships, and with it, too, comes out of disbelief into faith. Marry a word and separate with a word. He reaches the top of the heavens with a kind word, with which he will gain the pleasure of God, and the Lord of a word that the servant speaks to which God writes with our pleasure or throws him on his face in the fire. Emotions are inflamed, the United Nations is intensified with a word, and relations between states and war continue with a word.
What comes out of a person’s mouth is a translator that expresses the repository of his conscience and reveals the place of his bed, for it is evidence of
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