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Öğe Biosynthesis of silver nanoparticles and their versatile antimicrobial properties(Iop Publishing Ltd, 2019) Some, Sudip; Sen, Ipsita Kumar; Mandal, Amitava; Aslan, Tugrul; Ustun, Yakup; Yilmaz, Ebru Sebnem; Kati, AhmetSilver nanoparticles (AgNP) have been used for over a century for many purposes including as germicides. Unique physical, chemical and biological properties of Ag NPs make them suitable for a wide range of applications in different industries and biomedical fields. Green nanobiotechnology with synthesis of NPs using biomolecules (protein, enzyme, DNAand plant extracts) have become a rapidly developing research area. Green synthesis methods have overcome the disadvantages of traditional physical and chemical synthesis approaches, such as high cost, long time scales and toxicity. In the green route, the biomolecules act as both reducing and/or stabilizing agents to produce biocompatible NPs. Promising results on antimicrobial activity of AgNP against several pathogenic microorganisms have been reported in literature. The growth of multiple antibiotic resistant bacteria could be inhibited by using Ag NP. This review mainly discusses the synthesis routes and characterization of biomolecules capped Ag NPs and their enhanced antimicrobial properties towards various human and plant pathogens.Öğe Comparison of osteoconductive properties of three different ?-tricalcium phosphate graft materials: A pilot histomorphometric study in a pig model(Churchill Livingstone, 2015) Damlar, Ibrahim; Erdogan, Ozgur; Tatli, Ufuk; Arpag, Osman F.; Gormez, Ulas; Ustun, YakupAims: The aim of this study was to compare the de novo bone formation ability and osteoconductive effects of three different beta-tricalcium phosphate (beta-TCP) graft materials. The micro-architectural parameters of the newly formed bone tissues were also compared among the different graft materials. Material and methods: Eight male Swiss domestic pigs were used in the study. Five bony defects were made with a trephine bur. Three of the defects were filled with Cerasorb (R), Kasios (R) and Poresorb (R). The fourth defect was filled with an autogenous bone graft. The last defect remained empty. All subjects were sacrificed after 8 weeks. Results: When compared to a negative control group, significant healing was observed in all the groups except the Cerasorb group. The osteoconductivity of the Poresorb group was better than that of the other groups (p < 0.05). The difference in the osteoconductivity of the Kasios and Cerasorb groups was statistically significant (p < 0.05). Comparison of the micro-architectural properties of newly formed bone tissues retrieved from the defects showed that those filled with Poresorb were the best. Conclusion: beta-TCP materials show different results in terms of the volume and characteristics of new bone formation, although they have a similar chemical structure. (C) 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.Öğe Diagnostic Concordance Characteristics of Oral Cavity Lesions(Hindawi Ltd, 2013) Tatli, Ufuk; Erdogan, OzguR; Uguz, Aysun; Ustun, Yakup; Sertdemir, Yasar; Damlar, IbrahimPurpose. The objective of this study was to evaluate the diagnostic concordance characteristics of oral cavity lesions by comparing the clinical diagnosis of the lesions with the histopathologic diagnosis. Material and Method. A retrospective analysis was conducted on the patients, who were admitted with oral cavity pathology and underwent biopsy procedure between 2007 and 2011. The oral cavity lesions were classified into 6 different groups as odontogenic cysts, nonodontogenic cysts, odontogenic tumors, nonodontogenic tumors, malignant tumors, and precancerous lesions in accordance with the 2005 WHO classification. The diagnoses were also recategorized into 3 groups expressing prognostic implications as benign, precancerous, and malignant. The initial clinical diagnoses were compared with the histopathologic diagnoses. Data were analyzed statistically. Results. A total of 2718 cases were included. Histopathologic diagnosis did not match the clinical diagnosis in 6.7% of the cases. Nonodontogenic tumors and malignant tumors had the highest misdiagnosis rates (11.5% and 9%, resp.), followed by odontogenic tumors (7.7%), precancerous lesions (6.9%), and odontogenic cysts (4.4%). Clinicians were excelled in diagnosis of benign and precancerous lesions in clinical setting. Conclusion. The detailed discordance characteristics for each specific lesion should be considered during oral pathology practice to provide early detection without delay.Öğe Effect of Sterilization on Bond Strength and Mechanical Properties of Fiber Posts(Quintessence Publishing Co Inc, 2019) Yagci, Filiz; Ustun, Yakup; Zortuk, Mustafa; Agirnasligil, MehmetPurpose: To determine the effects of two different sterilization methods on the pull-out bond strength, flexural strength, and elastic modulus of glass-fiber posts. Materials and Methods: A total of 69 glass-fiber posts were used. The posts were divided into three groups according to applied sterilization method: 1) control, 2) ethylene oxide gas (EOG), and 3) autoclave. The microstructure of three posts from each group was evaluated by SEM and energy-dispersive X-ray spectroscopy (EDS). Thirty glass-fiber posts were used to evaluate pull-out bond strength. The three-point bending test was performed to analyze the flexural strength on another 30 glass-fiber posts. Failure modes were categorized microscopically after the pull-out test. After the three-point bending test, micromorphology at the bending area was examined using SEM. Results: One-way ANOVA indicated no statistically significant differences among the group means in terms of bond strength (p > 0.05), flexural strength (p > 0.05), or elastic modulus (p > 0.05). EDS revealed that the weight percentage of surface oxygen atoms in the EOG- and autoclave-sterilization groups were significantly higher. SEM images were similar. Conclusion: The results of this study show that glass-fiber posts can be sterilized either by autoclave or EOG when necessary, without any negative effect on bond strength, flexural strength, or elastic modulus.
