Fakülteler / Faculties
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Item Mechanical Behavior İnvestigation Of Fused Deposition Modeling Joints By Using Different Bonding Geometry With Variable Adhesive Thickness(RAPID PROTOTYPING JOURNAL, 2024-01-22) Kemiklioglu, Ugur; Demir, Sermet; Yuksel, CanerPurposeAdhesively bonded joints are used in many fields, especially in the automotive, marine, aviation, defense and outdoor industries. Adhesive bonding offers advantages over traditional mechanical methods, including the ability to join diverse materials, even load distribution and efficient thermal-electrical insulation. This study aims to investigate the mechanical properties of adhesively bonded joints, focusing on adherends produced with auxetic and flat surfaces adhered with varying adhesive thicknesses.Design/methodology/approachThe research uses three-dimensional (3D)-printed materials, polyethylene terephthalate glycol and polylactic acid, and two adhesive types with ductile and brittle properties for single lap joints, analyzing their mechanical performance through tensile testing. The adhesion region of one of these adherends was formed with a flat surface and the other with an auxetic surface. Adhesively bonded joints were produced with 0.2, 0.3 and 0.4 mm bonding thickness.FindingsResults reveal that auxetic adherends exhibit higher strength compared to flat surfaces. Interestingly, the strength of ductile adhesives in auxetic bonded joints increases with adhesive thickness, while brittle adhesive strength decreases with thicker auxetic bonds. Moreover, the auxetic structure displays reduced elongation under comparable force.Originality/valueThe findings emphasize the intricate interplay between adhesive type, bonded surface configuration of adherend and bonding thickness, crucial for understanding the mechanical behavior of adhesively bonded joints in the context of 3D-printed materials.Item Evaluation Of Gap Formation For Different Adhesive Agents In Primary Teeth With Optical Coherence Tomography(EUROPEAN ORAL RESEARCH, 2024-05-23) Uyar, Didem Sakaryali; Asena, Leyla; Tirali, Resmiye EbruPurpose This study aimed to evaluate gap formation between the tooth surface and restorative material in terms of microleakage by using optical coherence tomography (OCT) for self-etch and selective-etch applications of two different universal and one self-etch adhesives. Materials and Methods Sixty non-caries, primary molar teeth were divided into six groups; self-etch and selective-etch application ways of two different universal and one self-etch adhesive systems (n:10). After Class-V cavities were prepared, every tooth was distributed randomly in groups to apply adhesion procedure and then, all cavities were restored with polyacid-modified composite resin. Microleakage was evaluated by measuring the gap between the tooth surface and restoration by a blind researcher with Image J Software from OCT images. During statistical analysis, the significance level was accepted as p<0.05. Results According to the statistical analysis of the measurements obtained by Image J Software, selective-etch groups showed less gap formation than self-etch groups for each tested adhesive (p<0.05), and self-etch adhesive without etching showed significantly highest gap formation among all groups (p<0.05). Conclusion Universal adhesives with a selective-etching step might be preferred over self-etch adhesives for long-lasting polyacid-modified composite resin restorations in primary teeth. However, obtained results should be considered with another prospective clinical study for long-term prognosis.Item Exogenous Recombinant Adiponectin Improves Survival in Experimental Abdominal Sepsis(2014) Salman, Bulent; Yilmaz, Tonguc Utku; Tezcaner, Tugan; Demir, Ebru fluoglu; Pasaoglu, Ozge Tugce; 25337421Background: Adiponectin, which has anti-inflammatory features, is an important substance in several metabolic mechanisms. Aims: The aim of this study is to evauate the effects of exogenous intraperitoneal administration of adiponectin on the survival, intrabdominal adhesion and inflammatory cytokine levels in an experimental sepsis model. Study Design: Animal experimentation. Methods: Ninety rats were divided into a control group, adiponectin group and sham group. A cecal puncture abdominal sepsis model was performed in the adiponectin and control groups. Every three hours, exogenous adiponectin was administrated to the adiponectin group. At the 3(rd) and 24(th) hours, 10 rats were sacrified in each group in order to measure plasma tumor necrosis factor-alpha (TNF-alpha), interleukin (IL) 10, soluble intracellular adhesion molecule (ICAM)-1, IL-6 and macrophage inhibitory factor levels, and the activity of nuclear factor (NF)-kappa B. The remaining rats were followed for survival. Results: The plasma levels of TNF-alpha, soluable ICAM-1, IL-6, and macrophage inhibitory factor were significantly higher in the control group than in the adiponectin and sham group (p<0.05). The increase in inflammatory cytokines with time was more prominent in the control group. The activity of NF-kappa B in the control group was higher than in the adiponectin group (p<0.05). The survival rate of the adiponectin group was higher than in the control group. Conclusion: Administration of exogenous adiponectin to the peritoneum in abdominal sepsis increased survival and decreased intrabdominal adhesions by decreasing the inflammatory response.