Effect of different surface treatments on the shear bond strength of luting cements used with implant-supported prosthesis: An in vitro study

Degirmenci, Kubra,Saridag, Serkan The Korean Academy of Prosthodonitics 2020 The Journal of Advanced Prosthodontics Vol.12 No.2

PURPOSE. The aim of this study was to investigate the shear bond strength of luting cements used with implant retained restorations on to titanium specimens after different surface treatments. MATERIALS AND METHODS. One hundred twenty disc shaped specimens were used. They were divided into three groups considering the surface treatments (no treatment, sandblasting, and oxygen plasma treatment). Water contact angle of specimens were determined. The specimens were further divided into four subgroups (n=10) according to applied cement types: polycarboxylate cement (Adhesor Carbofine-AC), temporary zinc oxide free cement (Temporary CementZOC), non eugenol provisional cement for implant retained prosthesis (Premier Implant Cement-PI), and non eugenol acrylic-urethane polymer based provisional cement for implant luting (Cem Implant Cement-CI). Shear bond strength values were evaluated. Two-way ANOVA test and Regression analysis were used to statistical analyze the results. RESULTS. Overall shear bond strength values of luting cements defined in sandblasting groups were considerably higher than other surfaces (P<.05). The cements can be ranked as AC > CI > PI > ZOC according to shear bond strength values for all surface treatment groups (P<.05). Water contact angles of surface treatments (control, sandblasting, and plasma treatment group) were 76.17° ± 3.99, 110.45° ± 1.41, and 73.80° ± 4.79, respectively. Regression analysis revealed that correlation between the contact angle of different surfaces and shear bond strength was not strong (P>.05). CONCLUSION. The retentive strength findings of all luting cements were higher in sandblasting and oxygen plasma groups than in control groups. Oxygen plasma treatment can improve the adhesion ability of titanium surfaces without any mechanical damage to titanium structure.

Evaluation of reliability of zirconia materials to be used in implantretained restoration on the atrophic bone of the posterior maxilla: A finite element study

Kubra Degirmenci,Ayse Kocak-Buyukdere,Bulent Ekici 대한치과보철학회 2019 The Journal of Advanced Prosthodontics Vol.11 No.2

PURPOSE. Zirconia materials have been used for implant-retained restorations, but the stress distribution of zirconia is not entirely clear. The aim of this study is to evaluate the stress distribution and risky areas caused by the different design of zirconia restorations on the atrophic bone of the posterior maxilla. MATERIALS AND METHODS. An edentulous D4-type bone model was prepared from radiography of an atrophic posterior maxilla. Monolithic zirconia and zirconia-fused porcelain implant-retained restorations were designed as splinted or nonsplinted. 300-N occlusal forces were applied obliquely. Stress analyses were performed using a 3D FEA program. RESULTS. According to stress analysis, the bone between the 1) molar implant and the 2) premolar in the nonsplinted monolithic zirconia restoration model was stated as the riskiest area. Similarly, the maximum von Mises stress value was detected on the bone of the non-splinted monolithic zirconia models. CONCLUSION. Splinting of implant-retained restorations can be more critical for monolithic zirconia than zirconia fused to porcelain for the longevity of the bone.

Hazardousness Assessment of Persistent, Bioaccumulative and Toxic Substances

ONO, Yoshiro,DEGIRMENCI, Ebru 영남대학교 환경문제연구소 2000 環境硏究 Vol.20 No.1

Genotoxic chemicals have increasingly being used in our daily life. 180-chemicals were screened to identify the priority of hazardousness from the point of view of their genotoxicity. Umu-test was used to evaluate the genotoxicity of these chemicals. Some chemicals exhibited high genotoxic response. A scoring algorithm was developed to evaluate the hazardousness level of these chemicals based on their genoloxicity level and four other characteristics: biodegradation probability, soil adsorption coefficient (KOC), bioconcentration factor (BCF), Henry's Law constant (HLC). Then, these chemicals were sorted in a descending order of their hazardousness probability.

A Rare Congenital Anomaly: Interrupted Aortic Arch and Giant Ascending Aortic Aneurysm in a Young Male

Muhammed Hakan Tas,Ziya Simsek,Husnu Degirmenci,Hayri Ogul,Ugur Aksu,Abdulmecit Kantarci 대한심장학회 2013 Korean Circulation Journal Vol.43 No.8

Pararectal Migration of a Malleable Rod: An Unusual Late Complication

Ibrahim Kucukturkmen,Yusuf Kadir Topcu,Tansu Degirmenci,Ozgu Aydogdu,Ibrahim Halil Bozkurt,Serkan Yarimoglu,Salih Polat 대한남성과학회 2016 The World Journal of Men's Health Vol.34 No.2

A 75-year-old male had failed to respond conservative therapy for erectile dysfunction and had undergone insertion of a malleable penile prosthesis in 1995. Twenty years after the initial implant he presented with right-sided prosthesis localized in the buttock. There was no infection. The prosthesis was extracted through an incision in the right hip. As in the recent case, mechanical failures in malleable penile prosthesis models, can occur. Penile implant migration back to the buttock without a curve deformity is an extremely rare complication. Clinicians should be alert about possible late complications of penile prosthesis.

Left Atrial Thrombus in a Patient with Mitral Bioprosthetic Valve

Muhammed Hakan Tas,Ziya Simsek,Husnu Degirmenci,Hayri Ogul,Abdurrahim Colak,Huseyin Senocak 대한심장학회 2013 Korean Circulation Journal Vol.43 No.6

First-Line Mono-Chemotherapy in Frail Elderly Patients with Metastatic Colorectal Cancer

Varol, Umut,Dirican, Ahmet,Yildiz, Ibrahim,Oktay, Esin,Degirmenci, Mustafa,Alacacioglu, Ahmet,Barutca, Sabri,Karabulut, Bulent,Uslu, Ruchan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

Background: Unlike for fit elderly metastatic colorectal cancer (mCRC) patients, general approaches to initial treatment for the frail older mCRC patients are not clear. Our aim was to evaluate the efficiency and safety of first-line single-agent treatment in one such group. Materials and Methods: We retrospectively evaluated mCRC patients aged 70 or older with an Eastern Cooperative Oncology Group performance score of 2. They had no prior treatment and underwent first-line single-agent capecitabine or other monotherapies until disease progression or unacceptable toxicity. Results: Thirty-six patients were included. Most (n:28, 77.8%) were treated with capecitabine. One patient achieved a complete response and 5 patients had a partial response for an overall response rate of 16.6%. Twelve patients (33.3%) remained stable. Median progression free survival was 5 months (confidence interval (CI), %; 3.59-6.40) and median overall survival was 10 months (95 CI%; 8.1-11.8). Grade 3-4 toxicity was found in 6 patients (16.6%). Febrile neutropenia was not observed and there were no toxicity-associated deaths. Conclusions: Capecitabine is a safe chemotherapeutic agent with moderate activity for first-line treatment of older metastatic colorectal cancer patients with limited performance status.

Maximal Exercise-Corrected QT as a Predictor of Coronary Artery Disease: Comparison of Simpler Heart Rate Corrections

Aydın Akyuz,Seref Alpsoy,Dursun Cayan Akkoyun,Hasan Degirmenci,Niyazi Guler 대한심장학회 2013 Korean Circulation Journal Vol.43 No.10

Background and Objectives: The relationship between QT prolongation and myocardial ischemia is widely known. Due to the limited value of ST depression, we aimed to evaluate, by using four simpler heart rate corrections (Bazett, Framingham, Fridericia and Hodges), the value of maximal exercise-QTc prolongation in the diagnosis of coronary artery disease (CAD) presence and severity. Subjects and Methods: We enrolled 234 subjects (mean age 57.3±9 years, 143 men) who had undergone exercise testing and coronary angiography due to a suspicion of CAD in the study. Evaluating CAD severity with Gensini scoring, the CAD group (n=122) and controls with non-CAD were compared in terms of corrected QT duration at maximal exercise. Results: Age, gender, hypertension, dyslipidemia, smoking, exercise duration, resting, and peak heart rate were similar between the two groups (all p>0.05). The CAD group had higher raw QT values than the controls {268 (169-438) vs. 240 (168-348), p<0.001}. Although Fra-mingham QTc of ≥350 ms and Fridericia QTc of ≥340 ms were seen to be useful for the diagnosis of CAD, there was no additive diagnostic value of exercise QTc in addition to ST depression. Maximal exercise-QTc Bazett (r=0.163, p=0.01), Framingham (r=0.239, p=0.001), and Fri-dericia (r=0.206, p=0.001) equations were weakly positively correlated with Gensini scoring. Conclusion: The patients with CAD have longer QTc intervals at peak heart rates during exercise. This finding provides insufficient evid-ence to support routine incorporation of QTc at peak heart rates into exercise test interpretation.

Processing of agricultural apple fruit waste into sugar rich feedstocks for the catalytic production of 5-HMF over a Sn Amberlyst-15 resin catalyst

C.H.L. Tempelman,J.F. Jacobs,S. Ramkhelawan,A. Mok,W. van der Zalm,V. Degirmenci 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.99 No.-

In this study we considered processes of treatment of agricultural apple waste which is normallydiscarded. We show the effect of various pre-treatment procedures on thefinal catalytic performance toproduce 5-HMF from this real world biomass waste. Our study of the various potential pre-treatmentsteps, and their effect on the catalytic performance, provides valuable new insights which can be used forthe development of new processes for the localised small scale valorization of agricultural fruit waste. The apple waste is aimed to be converted into a sugar rich feedstock stream for the catalytic conversion to5-hydroxymethyl furfural (5-HMF) at low temperatures ( 120 C). Filters with varying pore sizes werestudied for thefiltration of apple pomace after milling the rotten apples in order to reduce the solidscontent. The testedfilters varied in pore sizes of 0.2 mm, 2 mm and 54 mm. The effect of heating, acid orbase treatment of the apple slurry was evaluated for increasing the speed offiltration. The highestflowrate was obtained for thefilter with 54 mm pores. The sugar richfiltrates were investigated in thecatalytic conversion to 5-HMF over an easy-to-manufacture Sn exchanged resin (Amberlyst-15) catalyst. Results showed thatfiltrates obtained over a 2 mmfilter lead to the highest 5-HMF yields (18 %) withoutextra additives. Adjustment of the reaction mixtures to pH 7 resulted in a lower catalytic activity. 5-HMFis proposed to be extracted from the aqueous layer by using an organic liquid layer (methyl isobutylketone, MIBK). In order to increase the diffusion of 5-HMF to the MIBK layer the addition of salts to thereaction mixture was investigated. This leads to lower catalytic activity, possibly due to catalystdeactivation. Our results showed that a relatively wide porefilter (54 mm) provides the fastest appleprocessing method and afiltrate reacting to the highest 5-HMF yield in catalytic conversion of the sugarrich product stream obtained from agricultural waste apples.

Patients with HER2-positive Early Breast Cancer Receiving Adjuvant Trastuzumab: Clinicopathological Features, Efficacy, and Factors Affecting Survival

Ulas, Arife,Kos, Tugba,Avci, Nilufer,Cubukcu, Erdem,Olmez, Omer Fatih,Bulut, Nilufer,Degirmenci, Mustafa Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.4

Background: The aim of the present study was to evaluate clinicopathological characteristics of our early stage breast cancer patients who are epidermal growth factor receptor 2 (HER2) overexpressed/amplified (HER2+), the efficacy of trastuzumab treatment and survival results. Materials and Methods: Patients with HER2-positive early stage breast cancer receiving adjuvant trastuzumab were investigated retrospectively. Clinicopathological features of 210 patients and treatment outcome were analysed. To evaluate survival rates, the Kaplan-Meier method was used. Univariate and multivariate analyses were conducted with the Cox regression model. Results: Mean age of the patients was 51.8, 71.9% being postmenopausal. Some 37.6% of patients were node negative, and 31% had T1 tumor size and 52.4% were positive for estrogen receptor. Of 210 patients, 89.5% completed planned 52 weeks adjuvant trastuzumab treatment. The median follow up was 27.5 months (6.0-86.0). Relapse free survival (RFS) was 68.0 months (95% CI: 62.1-74.0) and overall survival (OS) was 74.8 months (95% CI: 69.5-80.1). The 3 year OS for all patients was 92.0% and RFS was 79.6%. During follow up, relapse was detected at the rate of 14.3%. Trastuzumab associated cardiotoxicity was found at the rate of 3.3%. In univariate analyses, larger tumor size and grade III were significantly associated (p<0.05) with RFS. Multivariate analyses of covariates displaying p<0.05 identified grade III as an independent prognostic factor. Conclusions: In the present study, it was established that trastuzumab had a satisfactory safety profile and treatment efficacy as in other clinical studies and that among clinicopathological factors evaluated, only being grade 3 had a significant effect on RFS. The occurrence of relapse with adjuvant trastuzumab makes it necessary to identify molecular predictors, which will define this group better and help explain resistance to anti HER2 based therapies.