Influence of different universal adhesives on the repair performance of hybrid CAD-CAM materials

Demirel, Gulbike,Baltacioglu, Ismail Hakki The Korean Academy of Conservative Dentistry 2019 Restorative Dentistry & Endodontics Vol.44 No.3

Objectives: The aim of this study was to investigate the microshear bond strength (${\mu}SBS$) of different universal adhesive systems applied to hybrid computer-aided design/computer-aided manufacturing (CAD-CAM) restorative materials repaired with a composite resin. Materials and Methods: Four types of CAD-CAM hybrid block materials-Lava Ultimate (LA), Vita Enamic (VE), CeraSmart (CS), and Shofu Block HC (SH)-were used in this study, in combination with the following four adhesive protocols: 1) control: porcelain primer + total etch adhesive (CO), 2) Single Bond Universal (SB), 3) All Bond Universal (AB), and 4) Clearfil Universal Bond (CU). The ${\mu}SBS$ of the composite resin (Clearfil Majesty Esthetic) was measured and the data were analyzed using two-way analysis of variance and the Tukey test, with the level of significance set at p < 0.05. Results: The CAD-CAM block type and block-adhesive combination had significant effects on the bond strength values (p < 0.05). Significant differences were found between the following pairs of groups: VE/CO and VE/AB, CS/CO and CS/AB, VE/CU and CS/CU, and VE/AB and CS/AB (p < 0.05). Conclusions: The ${\mu}SBS$ values were affected by hybrid block type. All tested universal adhesive treatments can be used as an alternative to the control treatment for repair, except the AB system on VE blocks (the VE/AB group). The ${\mu}SBS$ values showed variation across different adhesive treatments on different hybrid CAD-CAM block types.

Clinical Factors Related with Helicobacter Pylori Infection - Is there an Association with Gastric Cancer History in First-Degree Family Members?

Demirel, Busra B.,Akkas, Burcu Esen,Vural, Gulin Ucmak Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Background: The aim of this study was to assess clinical factors associated with Helicobacter pylori positivity and to evaluate the incidence of gastric carcinoma in first-degree family members of infected patients. A total of 580 patients (mean age:$38{\pm}17$) with gastrointestinal complaints underwent C-14 urea breath test (UBT). Patients were grouped as: Group-1, untreated patients (n:384); and Group-2, patients who previously treated with eradication triple therapy (n:196). C-14 UBT was performed 1-2 months after the completion of eradication therapy. Associations of H pylori positivity with age, gender, ABO and Rhesus groups, smoking, dietary habits, and history of gastric cancer in first-degree family members were evaluated. The frequency of H pylori positivity was significantly higher in group-1 (58%) compared to group-2 (20%), p=0.001. There were no correlations between H pylori positivity and age, gender, ABO groups, Rhesus subgroups, smoking and dietary habits in both patient groups. The frequency of gastric cancer in family members was significantly higher in patients with H pylori infection among group-1, compared to infected patients among group-2 (56% vs. 28.6% respectively, p=0.03). We observed a significant association between H pylori positivity and the presence of gastric cancer in first-degree relatives of group-1 patients. Our results provide some confirmation of the presence of a link between gastric cancer development and H pylori. C-14 UBT is a sensitive, reliable and a widely recommended test for the detection of H pylori infection and recurrence. We suggest that detection and eradication of H pylori may contribute to a reduced risk of gastric cancer in the family members of infected patients.

Papillary Fibroelastoma of the Mitral Valve: an Unusual Cause of Mitral Valve Obstruction

Muhittin Demirel,Emrah Acar,Cüneyt Toprak,Servet İzci,Lütfi Öcal 대한심장학회 2017 Korean Circulation Journal Vol.47 No.2

Effects of powder particle size on mechanostructure and cell viability of the synthesised bioceramic bone grafts

Mehtap Demirel,Bunyamin Aksakal 한양대학교 세라믹연구소 2018 Journal of Ceramic Processing Research Vol.19 No.1

Hydroxyapatite (HA) based biografts were syntesized at 0.68, 1.2 and 2.4 μm powder particle size by sol gel method. The effectof powder particle sizes on morphology, mechanical properties and in vitro cell viability of the biografts were analysed. Eachcomposition at different particle sizes (0.68, 1.2 and 2.4 μm) were sintered at 1180 oC and quantitative phase analysis wascharacterized by FTIR, XRD and SEM-EDX. Mechanical properties were determined by axial compression and Vickershardness tests. The highest compresion strengths and hardness values were obtained in samples having the particle size of 0.68μm and such values were increased with decreased particle sizes. Furthermore, from in vitro Cell viability tests it wasdetermined that no toxicity was detected at 0,1 and 0,3 μM concentrations at lower powder particle sizes. However, cellviability was significantly reduced in the syntesized samples having 2.4 μm particle size at 0,3 μM concentration.

A Study on Structural Characterization of Thermally Stabilized PAN Precursor Fibers Impregnated with Ammonium Bromide before Carbonization Stage

Tuba Demirel,Md. Mahbubor Rahman,Kemal Şahin Tunçel,Ismail Karacan 한국섬유공학회 2022 Fibers and polymers Vol.23 No.11

Thermal-oxidative stabilization of polyacrylonitrile (PAN) fiber pretreated with ammonium bromide (NH4Br) wasperformed in the air atmosphere at temperatures between 200 and 250 °C for periods of 5 to 75 min in a multistep approach. The study demonstrates that the NH4Br incorporation is highly effective in accelerating nitrile group cyclization by reducingthe time required to form a thermally stable structure. After 60 min of the multistep stabilization, NH4Br incorporated andstabilized PAN was entirely thermally stable, infusible, and non-burning. XRD analysis showed the conversion of the pristinePAN molecular structure from a laterally ordered condition to a very disordered amorphous structure by crosslinking andaromatization process. Infrared analysis indicated rapid and concurrent aromatization and dehydrogenation reactions assistedby the formation of oxygen-containing functional groups. With the progression of the stabilization period, TGA thermogramsrevealed a comparative increase in thermal stability, as directed by the continuous rise of carbon yield. By decreasing therequired time for the stabilization process of PAN fiber, the use of NH4Br impregnation is expected to enhance carbon fiberproductivity at a reduced cost considerably.

Assessing Anticancer Potential of Blueberry Flavonoids, Quercetin, Kaempferol, and Gentisic Acid, Through Oxidative Stress and Apoptosis Parameters on HCT-116 Cells

Ebru Demirel Sezer,Latife Merve Oktay,Elif Karadadasx,Hikmet Memmedov,Nur Selvi Gunel,Eser So¨ zmen 한국식품영양과학회 2019 Journal of medicinal food Vol.22 No.11

In recent years, natural products gained popularity with their anti-inflammatory and antioxidant effects mediated by chemical compounds within their composition. Study results offering them as palliative therapy options in cancer or as anticancer agents with high levels of cytotoxicity brought a new approach to combine cancer treatment protocols with these products. From a different perspective, edible types of these products are suggested in daily diets due to their potential cancer preventive effects. Our preliminary work was on blueberry extracts (Vaccinium myrtillus) as a main representative of these natural products, and the contents of the extracts were analyzed with liquid chromatography tandem mass spectrometry (LC MS/MS) to reveal the composition and distribution of polyphenolic compounds within. The most abundant polyphenols detected in V. myrtillus extracts were quercetin, kaempferol, and a phenolic acid, gentisic acid (GA). The compounds were further evaluated on treated HCT-116 cells for their potential anticancer effects by measuring total antioxidant status, total oxidant status, and 8-hydroxydeoxyguanosine levels for evaluation of oxidative stress and through protein array analysis and flow cytometric analysis for evaluation of apoptosis. In analysis of oxidative stress parameters, reduced total oxidant levels and reduced oxidative stress index levels were found in cells treated with the compounds in comparison with untreated cells. In apoptosis-related protein profiles, at least twofold reduction in various apoptotic proteins was observed after quercetin and kaempferol treatment, whereas a different profile was observed for GA. Overall, results of this study showed that quercetin and kaempferol have strong cytotoxic, antioxidant, and apoptotic effects, although GA is mostly effective as an antioxidant polyphenol on HCT-116 cells.

Performance of Structural Lightweight Concrete containing Metakaolin after Elevated Temperature

Bahar Demirel,Ezgi Gultekin,Kursat Esat Alyamac 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

The aim of the current research is to determine the multiple influences of the amount of metakaolin and high temperature on the compressive strength of structural lightweight concrete (SLWC) applying response surface method (RSM). For this purpose, the lightweight concrete specimens were produced by pumice sand, and metakaolin replacing with cement at different ratios. The unit weight of hardened concrete, 28-day compressive strength, elevated temperature, ultrasonic pulse velocity, and sorptivity tests were performed. Moreover, then, two variables defined as the elevated temperature of 20, 400, 600, and 800 °C, and the metakaolin-tocement ratio of 0%, 5%, 11%, 18%, and 25%, to obtain the compressive strength of structural lightweight concrete. The effects of each variable on the response which is the compressive strength were determined following the ANOVA (analysis of variation) analysis, and the equation of the model was developed. Eventually, the developed equation could be utilized to estimate the compressive strength of the structural lightweight concrete for requested values of each variable.

Influence of different universal adhesives on the repair performance of hybrid CAD-CAM materials

Gülbike Demirel,İsmail Hakkı Baltacıoğlu 대한치과보존학회 2019 Restorative Dentistry & Endodontics Vol.44 No.3

Objectives: The aim of this study was to investigate the microshear bond strength (μSBS) of different universal adhesive systems applied to hybrid computer-aided design/computeraided manufacturing (CAD-CAM) restorative materials repaired with a composite resin. Materials and Methods: Four types of CAD-CAM hybrid block materials—Lava Ultimate (LA), Vita Enamic (VE), CeraSmart (CS), and Shofu Block HC (SH)—were used in this study, in combination with the following four adhesive protocols: 1) control: porcelain primer + total etch adhesive (CO), 2) Single Bond Universal (SB), 3) All Bond Universal (AB), and 4) Clearfil Universal Bond (CU). The μSBS of the composite resin (Clearfil Majesty Esthetic) was measured and the data were analyzed using two-way analysis of variance and the Tukey test, with the level of significance set at p < 0.05. Results: The CAD-CAM block type and block-adhesive combination had significant effects on the bond strength values (p < 0.05). Significant differences were found between the following pairs of groups: VE/CO and VE/AB, CS/CO and CS/AB, VE/CU and CS/CU, and VE/ AB and CS/AB (p < 0.05). Conclusions: The μSBS values were affected by hybrid block type. All tested universal adhesive treatments can be used as an alternative to the control treatment for repair, except the AB system on VE blocks (the VE/AB group). The μSBS values showed variation across different adhesive treatments on different hybrid CAD-CAM block types.

Diffuse Myocardial Uptake of 99mTc-HDP in Multiple Myeloma

Koray Demirel,Murat Sadic,Meliha Korkmaz,Aylin Comak,Hasan Ikbal Atilgan,Gökhan Koca 대한핵의학회 2013 핵의학 분자영상 Vol.47 No.3

Soft tissue uptake is a rare finding in bone scintigraphy,with an incidence of 2%. Although the mechanism has not yet been fully clarified, several causes have been reported for this unusual uptake pattern. This paper presents a case of diffuse myocardial accumulation of technetium-99m hydroxymethylene diphosphonate (99mTc-HDP) without either solid/visceral organ or soft tissue with multiple myeloma (MM) in skeletal scintigraphy. A 93-year-old man with hypertension and chronic heart failure for 14 years underwent bone scanning due to a 2-month history of back pain within a 1-year period of MM. Three hours later,99mTc-HDP late static images showed diffuse myocardial radiotracer accumulation and there were no other sites of abnormal soft tissue or visceral uptake. Myocardial accumulation had disappeared on 24-h delayed static images. This accumulation was thought to be related with AL-type amyloidosis associated with MM.

Decreased Expression of α-Synuclein, Nogo-A and UCH-L1 in Patients with Schizophrenia: A Preliminary Serum Study

Ömer Faruk Demirel,İhsan Cetin,Şenol Turan,Tarık Sağlam,Nazım Yıldız,Alaattin Duran 대한신경정신의학회 2017 PSYCHIATRY INVESTIGATION Vol.14 No.3

Objective: α-synuclein, Nogo-A and Ubiquitin C-terminal hydrolase L1 (UCH-L1) have neuromodulatory roles for human brain. Therefore, abnormalities of these molecules are associated with neuropsychiatric disorders. Although some serum studies in the other disorders have been made, serum study of α-synuclein, Nogo-A and UCH-L1 is not present in patients with schizophrenia and healthy controls. Therefore, our aim was to compare serum levels of α-synuclein, Nogo-A and UCH-L1 of the patients with schizophrenia and healthy controls. Methods: Forty-four patients with schizophrenia who is followed by psychotic disorders unit, and 40 healthy control were included in this study. Socio-demographic form and Positive and Negative Syndrome Scale (PANSS) was applied to patients, and sociodemographic form was applied to control group. Fasting bloods were collected and the serum levels of α-synuclein, Nogo-A and UCH-L1 were measured by ELISA method. Results: Serum α-synuclein [patient: 12.73 (5.18–31.84) ng/mL; control: 41.77 (15.12–66.98) ng/mL], Nogo-A [patient: 33.58 (3.09–77.26) ng/mL; control: 286.05 (136.56–346.82) ng/mL] and UCH-L1 [patient: 5.26 (1.64–10.87) ng/mL; control: 20.48 (11.01–20.81) ng/mL] levels of the patients with schizophrenia were significianly lower than healthy controls (p<0.001). Conclusion: Our study results added new evidence for explaining the etiopathogenesis of schizophrenia on the basis of neurochemical markers.