1.Correlation between microleakage and screw loosening at implant-abutment connection.
The Journal of Advanced Prosthodontics 2014;6(1):35-38
PURPOSE: This study aimed to evaluate the correlation between microleakage and screw loosening at different types of implant-abutment connections and/or geometries measuring the torque values before and after the leakage tests. MATERIALS AND METHODS: Three different abutment types (Intenal hex titanium, internal hex zirconium, morse tapered titaniuim) with different geometries were connected to its own implant fixture. All the abutments were tightened with a standard torque value then the composition was connected to the modified fluid filtration system. After the measurements of leakage removal torque values were re-measured. Kruskal-wallis test was performed for non-parametric and one-way ANOVA was performed for parametric data. The correlation was evaluated using Spearman Correlation Test (alpha=0.05). RESULTS: Significantly higher microleakage was found at the connection of implant-internal hex zirconium abutment. Observed mean torque value loss was also significantly higher than other connection geometries. Spearman tests revealed a significant correlation between microleakage and screw loosening. CONCLUSION: Microleakage may provoke screw loosening. Removing torque values rationally decrease with the increase of microleakage.
Filtration
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Titanium
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Torque
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Zirconium
2.Mirror Image Gerbode or Partial Atrioventricular Canal Defect?.
Cem ARITURK ; Ahmet Umit GULLU ; Sahin SENAY ; Eyup Murat OKTEN ; Fevzi TORAMAN ; E Hasan KARABULUT ; Letisya MELENGIC ; Cem ALHAN
The Korean Journal of Thoracic and Cardiovascular Surgery 2015;48(6):404-406
Gebode defect, that can accurately be treated surgical repair, is defined as a true communication between left ventricle and right atrium. A 74-year-old woman with a worsening history of ortophnea and peripheral edema was hospitalised. A communication between right atrium and left ventricle was diagnosed using transeusophageal echocardiography. The defect was repaired and mitral valve was replaced with a biologic valve. It would be beter to tailor surgical strategy for each case with atrioventricular canal defect after preoperative transeusophageal echocardiography and peroperative direct sight.
Aged
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Echocardiography
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Edema
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Female
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Heart Atria
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Heart Ventricles
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Humans
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Mitral Valve
3.What is the changing frequency of diamond burs?
Faruk EMIR ; Simel AYYILDIZ ; Cem SAHIN
The Journal of Advanced Prosthodontics 2018;10(2):93-100
PURPOSE: The purpose of this study was to determine the changing frequency of a diamond bur after multiple usages on 3 different surfaces. MATERIALS AND METHODS: Human premolar teeth (N = 26), disc shaped direct metal laser sintered CoCr (N = 3) and zirconia specimens (N = 3) were used in this study. Groups named basically as Group T for teeth, Group M for CoCr, and Group Z for zirconia. Round tapered black-band diamond bur was used. The specimens were randomly divided into three groups and placed with a special assembly onto the surveyor. 1, 5, and 10 preparation protocols were performed to the first, second, and third sub-groups, respectively. The subgroups were named according to preparation numbers (1, 5, 10). The mentioned bur of each group was then used at another horizontal preparation on a new tooth sample. The same procedure was used for CoCr and zirconia disc specimens. All of the bur surfaces were evaluated using roughness analysis. Then, horizontal tooth preparation surfaces were examined under both stereomicroscope and SEM. The depth maps of tooth surfaces were also obtained from digital stereomicroscopic images. The results were statistically analyzed using One-Way ANOVA, and the Tukey HSD post-hoc tests (α=.05). RESULTS: All of the groups were significantly different from the control group (P < .001). There was no significant difference between groups Z5 and Z10 (P=.928). Significant differences were found among groups T5, M5, and Z5 (P < .001). CONCLUSION: Diamond burs wear after multiple use and they should be changed after 5 teeth preparations at most. A diamond bur should not be used for teeth preparation after try-in procedures of metal or zirconia substructures.
Bicuspid
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Dental Instruments
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Diamond
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Humans
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Tooth
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Tooth Preparation
4.Effect of biofilm formation, and biocorrosion on denture base fractures.
Cem SAHIN ; Alper ERGIN ; Simel AYYILDIZ ; Erdal COSGUN ; Gulay UZUN
The Journal of Advanced Prosthodontics 2013;5(2):140-146
PURPOSE: The aim of this study was to investigate the destructive effects of biofilm formation and/or biocorrosive activity of 6 different oral microorganisms. MATERIALS AND METHODS: Three different heat polymerized acrylic resins (Ivocap Plus, Lucitone 550, QC 20) were used to prepare three different types of samples. Type "A" samples with "V" type notch was used to measure the fracture strength, "B" type to evaluate the surfaces with scanning electron microscopy and "C" type for quantitative biofilm assay. Development and calculation of biofilm covered surfaces on denture base materials were accomplished by SEM and quantitative biofilm assay. According to normality assumptions ANOVA or Kruskal-Wallis was selected for statistical analysis (alpha=0.05). RESULTS: Significant differences were obtained among the adhesion potential of 6 different microorganisms and there were significant differences among their adhesion onto 3 different denture base materials. Compared to the control groups after contamination with the microorganisms, the three point bending test values of denture base materials decreased significantly (P<.05); microorganisms diffused at least 52% of the denture base surface. The highest median quantitative biofilm value within all the denture base materials was obtained with P. aeruginosa on Lucitone 550. The type of denture base material did not alter the diffusion potential of the microorganisms significantly (P>.05). CONCLUSION: All the tested microorganisms had destructive effect over the structure and composition of the denture base materials.
Acrylic Resins
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Biofilms
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Denture Bases
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Dentures
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Diffusion
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Hot Temperature
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Microscopy, Electron, Scanning
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Polymers
5.NLRP1-Mediated Antidepressant Effect of Ketamine in ChronicUnpredictable Mild Stress Model in Rats
Feyza ARICIOĞLU ; Canan YALCINKAYA ; Ceren Sahin OZKARTAL ; Erdem TUZUN ; Serap SIRVANCI ; Cem Ismail KUCUKALI ; Tijen UTKAN
Psychiatry Investigation 2020;17(4):283-291
Objective:
NOD-like receptor protein 1 (NLRP1) inflammasome complex has been recently associated with chronic unpredictablemild stress (CUMS) model of depression. Our aim was to investigate whether ketamine-induced antidepressant effect is associated withsuppression of NLRP1.
Methods:
Wistar albino rats were divided into control, CUMS, CUMS+acute ketamine (a single 10 mg/kg dose) and CUMS+chronicketamine (daily 10 mg/kg injections for 3 weeks) groups (n=10 for each group). Sucrose preference test and forced swimming test wereperformed to assess anhedonia and immobility time respectively for the severety of depression symptoms. Brain tissues were dissectedand prefrontal cortex and hippocampus regions were used for real-time polymerase chain reaction (PCR) and immunohistochemicalanalysis.
Results:
CUMS procedure significantly induced depressive-like symptoms whereas both acute and chronic ketamine treatment amelioratedthem. mRNA expression levels of NLRP1, caspase 1, apoptosis-associated speck-like protein containing a CARD (ASC), NF-κB,endothelial nitric oxide synthase, IL-1β, IL-6, toll-like receptor 4 (TLR-4) and purinergic 2×7 receptor (P2X7R) and numbers of Iba-1+and GFAP+glial cells were reduced by acute and/or chronic ketamine treatment.
Conclusion
In the present study for the first time upstream and downstream elements of the NLRP1 inflammasome complex are shownto be suppressed by ketamine thus reinforcing the involvement of NLRP1 in the physiopathology of depression.Psychiatry Investig 2020;17(4):283-291
6.Antidepressant-like Effects Induced by Chronic Blockade of the Purinergic 2X7 Receptor through Inhibition of Non-like Receptor Protein 1 Inflammasome in Chronic Unpredictable Mild Stress Model of Depression in Rats
Feyza ARICIOGLU ; Ceren Sahin OZKARTAL ; Tugce BASTASKIN ; Erdem TÜZÜN ; Cansu KANDEMIR ; Serap SIRVANCI ; Cem Ismail KUCUKALI ; Tijen UTKAN
Clinical Psychopharmacology and Neuroscience 2019;17(2):261-272
OBJECTIVE: Purinergic 2X7 receptor (P2X7R) activation is known to be involved in pathogenesis of depression. Our aims were to investigate P2X7R-activated inflammasome pathways in parallel with induction of depression and to test the antidepressant-like effects of the selective P2X7R antagonist Brilliant Blue G (BBG) in a rat model of chronic unpredictable mild stress (CUMS). METHODS: Male Wistar albino rats were divided into control, CUMS, CUMS+BBG25 (25 mg/kg/day) and CUMS+BBG50 (50 mg/kg/day) groups (n=10 for each group). Various stressors were applied to rats for 6 weeks to establish the CUMS model and daily BBG treatment was started at the end of 3rd week. Sucrose preference test and forced swim test (FST) were performed to assess antidepressant-like effects. Brain samples were obtained for real-time polymerase chain reaction and immunohistochemistry analysis. RESULTS: In FST, duration of immobility was reduced in the CUMS+BBG50 group. Also, BBG treatment significantly enhanced sucrose preference. While NLRP3 gene expression levels were unchanged in rats exposed to the CUMS protocol, expression levels of other inflammasome pathway factors NLRP1, caspase-1, ASC, NF-κB, IL-1β, IL-6 and P2X7R were increased. BBG treatment reduced expression levels of these factors. Likewise, Iba-1 and GFAP immunoreactivities were enhanced by the CUMS protocol and this action was reversed by BBG treatment. CONCLUSION: Chronic administration of BBG in CUMS model results in antidepressant-like activity in a dose dependent manner. Molecular and histological results show that these effects might be at least partially related to the suppression of inflammasome-related neuroinflammatory responses and suggest involvement of NLRP1 in depression.
Animals
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Brain
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Depression
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Gene Expression
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Humans
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Immunohistochemistry
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Inflammasomes
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Interleukin-6
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Male
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Models, Animal
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Rats
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Real-Time Polymerase Chain Reaction
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Receptors, Purinergic P2
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Receptors, Purinergic P2X7
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Sucrose