18 results on '"Orhan M"'
Search Results
2. List of Contributors
- Author
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Al-Maadid, A., primary, Andrikopoulos, P., additional, Black, E.L., additional, Burchi, A., additional, Demir, N., additional, Ezzat, H., additional, Galindo, G., additional, Giorgioni, G., additional, Gregoriou, G.N., additional, Keefe, H.G., additional, Kok, S.K., additional, McFall Lamm, Jr., R., additional, Martelli, D., additional, Niklewski, J., additional, Nogare, S., additional, Orhan, M., additional, Oskenbayev, Y., additional, Patra, S., additional, Qin, Z., additional, Rengifo, E.W., additional, Rodgers, T., additional, Sabdenaliyev, B., additional, Solakoglu, M.N., additional, Spagnolo, F., additional, Spagnolo, N., additional, Spiru, A., additional, Tanna, S., additional, Trendafilov, R., additional, Uludag, B.K., additional, Vagenas-Nanos, E., additional, Vivian, A., additional, Wu, M., additional, and Yousef, I., additional
- Published
- 2016
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3. and transport properties
- Author
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Orhan, M, Kinaci, A, and Cagin, T
- Subjects
Acetonitrile ,SWCNT ,Molecular dynamics ,Viscosity ,Self-diffusion - Abstract
In the first part of our study, here an all atom molecular dynamic study on the effect of confinement on structure, dynamic and transport properties of acetonitrile is presented. For this purpose, Single Walled Carbon Nanotubes (SWCNTs) were filled with the acetonitrile by employing isothermal-isobaric ensemble followed by canonical ensemble molecular dynamics simulations for investigating interactions between the acetonitrile and SWCNTs. Several interesting features of the acetonitrile were identified as the diameter of CNTs becomes smaller. First, two distinct regions were identified i.e., a core region along the longitudinal direction dominated by rarefaction effects and an interface shell with relatively high density of fluid. Volume of rarefied region decreases with larger values of tube diameters. Secondly, interfacial mobility in the vicinity fluid-CNT interface favors axial mean squared displacements of the acetonitrile molecules. Analyses also show that radial mobility of the molecules strongly depends on the size of the core region and diameter of the tube whereas the axial self-diffusion coefficient varies almost exponentially with the tube diameter. Thirdly, a preferred coordination between each pair of the C (methyl group carbon), C (nitrile group carbon) and N atoms, and an ordering in the vicinity of wall were observed contrary to those of larger tubes. Fourthly, we observed that the E-2g mode frequencies of SWCNT dominates those of C1-C2-N bending and C1-C2 stretching modes. The frequencies of both SWCNTs and those of the fluid are the same in these modes. Lastly, the shear viscosity diminishes with the diameter of the tube. (C) 2020 Elsevier B.V. All rights reserved. C1 [Orhan, Mehmet] Pamukkale Univ, Dept Mech Engn, TR-20160 Pamukkale, Turkey. [Kinaci, Alper] Northwestern Univ, Evanston, IL 60208 USA. [Cagin, Tahir] Texas A&M Univ, Dept Mat Sci & Engn, 209 Reed McDonald Bldg, College Stn, TX 77843 USA.
- Published
- 2020
4. Manual heating of the radial artery (Balbay maneuver) to facilitate radial puncture prior to transradial coronary catheterization
- Author
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Sefa Ünal, Burak Açar, Çağrı Yayla, Mustafa Mücahit Balci, Ahmet Göktuğ Ertem, Meryem Kara, Orhan Maden, Ahmet Temizhan, Muharrem Tola, and Yücel Balbay
- Subjects
Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Objective: Transradial access is widely used for both diagnostic and interventional cardiac procedures. The use of transradial access offers several advantages, including decreased bleeding, fewer vascular complications, and reduced length of hospital stay and cost. However, the small size of the radial artery limits the size of the equipment that can be used via this approach. In this study we sought to investigate whether preprocedural manual heating of the radial artery facilitates radial artery puncture. Methods: Patients undergoing transradial cardiac catheterization were randomized to subcutaneous nitroglycerin plus diltiazem or manual heating. The study endpoint was puncture score (score 1: easiest – puncture at first attempt; score 2: second attempt; score 3: third attempt; score 4: fourth attempt or more; score 5: puncture failed). Results: Ninety consecutive patients were enrolled in the study, 45 allocated to the drug treatment group and 45 to the heating group. Patients underwent radial artery ultrasound before catheterization. Complications were rare: one hematoma (drug treatment group) and one radial artery occlusion (heating group). Baseline demographic and clinical characteristics were similar. Baseline radial artery diameter was similar in both groups (2.41±0.46 mm and 2.29±0.48 mm in the heating and drug treatment groups, respectively). However, the median puncture score was lower in the heating group (1; interquartile range 1-2) compared to the drug treatment group (2; interquartile range 1-3; p=0.001). Conclusions: Preprocedural manual heating of the radial artery facilitates radial artery puncture in patients undergoing transradial cardiac catheterization. Resumo: Objetivo: O acesso transradial (ATR) é usado habitualmente quer para procedimentos diagnósticos quer de intervenção coronária. O uso de ATR oferece várias vantagens: redução das hemorragias, menos complicações vasculares, menor tempo de internamento e representa menos custos associados. Porém, o reduzido calibre da artéria radial limita o tamanho dos dispositivos que podem ser usados por este acesso. Neste estudo, investigamos se o prévio aquecimento da artéria radial facilita, ou não, a punção radial. Métodos: Doentes submetidos a cateterismo cardíaco por ATR foram aleatorizados para uma administração subcutânea de uma combinação de nitroglicerina e diltiazem ou, em alternativa, aquecimento manual da artéria radial. O endpoint do estudo foi o score de punção (score 1: punção simples à primeira tentativa; score 2: punção à segunda tentativa; score 3: punção à terceira tentativa; score 4: punção à quarta ou mais tentativa; score 5: punção radial falhada). Resultados: Noventa doentes consecutivos foram incluídos no estudo – 45 no grupo de tratamento farmacológico e 45 no grupo de aquecimento manual. Os doentes fizeram avaliação ecográfica da artéria radial antes do cateterismo. As complicações ocorreram de forma rara: um hematoma (grupo tratamento) e uma oclusão radial (grupo aquecimento). As caraterísticas basais demográficas e clínicas foram semelhantes. O diâmetro basal da artéria radial foi semelhante em ambos os grupos (2,41 ± 0,46 mm e 2,29 ± 0,48 mm nos grupos de aquecimento e de tratamento, respetivamente). No entanto, o score de punção foi mais baixo no grupo aquecimento (1; intervalo interquartil 1-2) comparado com o grupo tratamento (2; intervalo interquartil 1-3; p=0,001). Conclusões: O aquecimento manual da artéria radial facilita a punção radial em doentes submetidos a cateterismo cardíaco por via transradial. Keywords: Cardiac catheterization, Manual heating, Transradial access, Palavras-chave: Cateterização coronária, Aquecimento manual, Acesso transradial
- Published
- 2017
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5. ‘Action potential-like’ ST elevation following pseudo-Wellens' electrocardiogram
- Author
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Fatih Oksuz, Baris Sensoy, Fatih Sen, Ethem Celik, Ozcan Ozeke, and Orhan Maden
- Subjects
Vasospastic angina ,ST segment elevation ,Wellens' syndrome ,Surgery ,RD1-811 ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Coronary artery vasospasm is an important cause of chest pain syndromes that can lead to myocardial infarction, ventricular arrhythmias, and sudden death. In 1959, Prinzmetal et al described a syndrome of nonexertional chest pain with ST-segment elevation on electrocardiography. Persistent angina is challenging, and repeated coronary angioplasty may be required in this syndrome. Calcium antagonists are extremely effective in treating and preventing coronary spasm, and may provide long-lasting relief for the patient. Whereas the Wellens' syndrome is characterized by symmetrically inverted T-waves with preserved R waves in the precordial leads suggestive of impending myocardial infarction due to a critical proximal left anterior descending stenosis, the pseudo-Wellens' syndrome caused by coronary artery spasm has also rarely been reported in literature. We present a pseudo-Wellens syndrome as a cause of vasospastic angina, and a diffuse ST segment elavation on electrocardiogram resembling the Greek letter lambda, called also 'action potential-like' ECG in a patient with vasospastic-type Printzmetal angina.
- Published
- 2015
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6. Comparison of the Electrocardiographic Features of Complete Left Bundle Branch Block in Patients with Ischemic and Nonischemic Left Ventricular Dysfunction
- Author
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Tumer Erdem Guler, Kumral Ergun, Aytun Canga, Orhan Maden, Serkan Topaloglu, Mehmet Timur Selcuk, Ozgul Malcok Gurel, Mehmet Fatih Ozlu, Ozcan Ozeke, Veli Kaya, and Dursun Aras
- Subjects
left bundle branch block ,ischemic left ventricular dysfunction ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background: Differentiating ischemic (ILVD) from nonischemic left ventricular dysfunction (NILVD) is important prognostically and therapeutically but might be difficult clinically. The differentiating role of electrocardiographic (ECG) features in the presence of left bundle-branch block (LBBB) is debatable on differentiating ILVD from NILVD.Objective: The present study assessed whether there is the role of certain ECG features in differentiating ILVD from NILVD in the presence of the complete LBBB.Methods and Results: Patients who had LBBB were divided into two groups based on the presence and type of left ventricular dysfunction; (1) ILVD group (49 patients; 20 female; age: 65 ± 11 years) and (2) NILVD group (49 patients; 22 female; age: 59 ± 12 years), and numerous ECG features were compared. Most of these ECG features did not show any difference between the groups except for following ECG findings; the voltage of R wave in V6 were statistically higher in NILVD group compared ILVD group (p: 0.03); the depression of the ST-J point by more than 0.2 mV in V6 were also frequently observed in NILVD group compared ILVD group (5/ 10% vs 19/ 39% , p: 0.001); and the notching in the ascending or descending limb of the S wave in V1-4 leads were more in ILVD group (18/ 36% vs 8/ 16% p: 0.03; 9/ 16% vs 2/ 4%, p: 0.03, respectively).Conclusions: In the current study, although some ECG findings were found to be useful, ECG features in the presence of complete LBBB had poor value in differentiating ILVD from NILVD.
- Published
- 2007
7. Sex Differences Among Older Adults With Bipolar Disorder: Results From the Global Aging & Geriatric Experiments in Bipolar Disorder (GAGE-BD) Project.
- Author
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Blanken MAJT, Oudega ML, Almeida OP, Schouws SNTM, Orhan M, Beunders AJM, Klumpers UMH, Sonnenberg C, Blumberg HP, Eyler LT, Forester BP, Forlenza OV, Gildengers A, Mulsant BH, Rajji T, Rej S, Sarna K, Sutherland A, Yala J, Vieta E, Tsai S, Briggs FBS, Sajatovic M, and Dols A
- Subjects
- Aged, Female, Humans, Male, Affect, Aging psychology, Comorbidity, Sex Characteristics, Middle Aged, Bipolar Disorder epidemiology, Bipolar Disorder drug therapy
- Abstract
Objective: Sex-specific research in adult bipolar disorder (BD) is sparse and even more so among those with older age bipolar disorder (OABD). Knowledge about sex differences across the bipolar lifespan is urgently needed to target and improve treatment. To address this gap, the current study examined sex differences in the domains of clinical presentation, general functioning, and mood symptoms among individuals with OABD., Methods: This Global Aging & Geriatric Experiments in Bipolar Disorder (GAGE-BD) study used data from 19 international studies including BD patients aged ≥50 years (N = 1,185: 645 women, 540 men).A comparison of mood symptoms between women and men was conducted initially using two-tailed t tests and then accounting for systematic differences between the contributing cohorts by performing generalized linear mixed models (GLMMs). Associations between sex and other clinical characteristics were examined using GLMM including: age, BD subtype, rapid cycling, psychiatric hospitalization, lifetime psychiatric comorbidity, and physical health comorbidity, with study cohort as a random intercept., Results: Regarding depressive mood symptoms, women had higher scores on anxiety and hypochondriasis items. Female sex was associated with more psychiatric hospitalizations and male sex with lifetime substance abuse disorders., Conclusion: Our findings show important clinical sex differences and provide support that older age women experience a more severe course of BD, with higher rates of psychiatric hospitalization. The reasons for this may be biological, psychological, or social. These differences as well as underlying mechanisms should be a focus for healthcare professionals and need to be studied further., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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8. Quasi-static and dynamic Brazilian testing and failure analysis of a deer antler in the transverse to the osteon growth direction.
- Author
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Tuncer C, Güden M, Orhan M, Sarıkaya MK, and Taşdemirci A
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- Animals, Haversian System, Brazil, Antlers, Deer, Fractures, Bone
- Abstract
The transverse tensile strength of a naturally fallen red deer antler (Cervus Elaphus) was determined through indirect Brazilian tests using dry disc-shape specimens at quasi-static and high strain rates. Dynamic Brazilian tests were performed in a compression Split-Hopkinson Pressure Bar. Quasi-static tensile and indirect Brazilian tests were also performed along the osteon growth direction for comparison. The quasi-static transverse tensile strength ranged 31.5-44.5 MPa. The strength increased to 83 MPa on the average in the dynamic Brazilian tests, proving a rate sensitive transverse strength. The quasi-static tensile strength in the osteon growth direction was however found comparably higher, 192 MPa. A Weibull analysis indicated a higher tensile ductility in the osteon growth direction than in the transverse to the osteon growth direction. The microscopic analysis of the quasi-static Brazilian test specimens (tensile strain along the osteon growth direction) revealed a micro-cracking mechanism operating by the crack deflection/twisting at the lacunae in the concentric lamellae region and at the interface between concentric lamellae and interstitial lamellae. On the other side, the specimens in the transverse direction fractured in a more brittle manner by the separation/delamination of the concentric lamellae and pulling of the interstitial lamellae. The detected increase in the transverse strength in the high strain rate tests was further ascribed to the pull and fracture of the visco-plastic collagen fibers in the interstitial lamellae. This was also confirmed microscopically; the dynamically tested specimens exhibited flatter fracture surfaces., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
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- 2023
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9. Effect of cortical bone thickness and density on pullout strength of mini-implants: An experimental study.
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Erbay Elibol FK, Oflaz E, Buğra E, Orhan M, and Demir T
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- Bone Density, Bone and Bones, Humans, Cortical Bone anatomy & histology, Dental Implants, Orthodontic Anchorage Procedures
- Abstract
Introduction: Anchorage, which is defined as resistance against undesired tooth movements, is one of the most important factors in success of orthodontic treatment. In recent years, mini-implants have been used instead of uncomfortable headgears and Nance appliances. The pullout test is the most common method for measuring the anchorage capacity of mini-implants. The aim of this study was to investigate the effects of cortical bone thickness and cortical layer bone density on pullout strength of mini-implants., Methods: Mini-implants were placed in polyurethane foam blocks representing 3 different cortical thicknesses (1 mm, 2 mm, and 3 mm) and 3 different cortical bone densities (grade 40, grade 45, and grade 50). Pullout tests were performed with 5 mm/min loading rate. Load vs displacement values were recorded during the tests., Results: Comparing cortical thicknesses on the same bone densities, statistically significant differences were found between 1 mm, 2 mm, and 3 mm thicknesses. Likewise, comparing bone densities on the same cortical thicknesses, statistically significant differences were found among all groups. Spearman rank tests showed that both cortical thickness and cortical bone density are correlated with pullout strength (rs, 0.548; P <0.001 and rs, 0.691; P <0.001, respectively)., Conclusions: Although both factors are positively correlated with pullout strength, the effect of cortical bone density was the dominant factor affecting primary stability., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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10. Effects of modified and conventional facemask therapies with expansion on dynamic measurement of natural head position in Class III patients.
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Yagci A, Uysal T, Usumez S, and Orhan M
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- Adenoids pathology, Biomechanical Phenomena, Cephalometry, Child, Female, Follow-Up Studies, Humans, Incisor pathology, Male, Malocclusion, Angle Class III pathology, Mandible pathology, Nasal Bone pathology, Pharynx anatomy & histology, Posture physiology, Prospective Studies, Sella Turcica pathology, Stress, Mechanical, Time Factors, Tongue anatomy & histology, Extraoral Traction Appliances, Head anatomy & histology, Malocclusion, Angle Class III therapy, Orthodontic Appliance Design, Orthodontics, Corrective instrumentation, Palatal Expansion Technique instrumentation
- Abstract
Introduction: The aim of this prospective clinical trial was to assess the effects of varying force directions on the dynamic measurement of natural head position and orofacial airway dimensions of Class III patients during maxillary orthopedic protraction compared with an untreated control group., Methods: The conventional facemask group comprised 15 patients (8 girls, 7 boys; mean age, 9.6 ± 1.3 years), the modified facemask group comprised 15 patients (7 girls, 8 boys; mean age, 9.5 ± 1.5 years), and the control group comprised 15 subjects (7 girls, 8 boys; mean age, 9.8 ± 1.6 years). Natural head position measurements and cephalometric records were obtained from all subjects before and after treatment or the control period (approximately 1 year). An inclinometer and a portable data logger were used to collect the dynamic natural head position data. For statistical comparisons, paired samples t tests, analysis of variance (ANOVA), and post-hoc Tukey tests were used at the P <0.05 level., Results: Both treatment groups showed statistically significant changes in the sagittal (pitch) measurements of natural head position and upper pharynx, aerial, and total area of airway measurements during the treatment period. In the control group, the only statistically significant change was an increased upper pharynx measurement (P = 0.020). According to the intergroup comparisons, statistically significant natural head position differences were found in the conventional (6.4° flexion) and the modified (5.7° flexion) facemask groups when compared with the controls. The modified facemask group also showed significant changes in aerial (P = 0.003) and total (P <0.001) areas of the airway measurements compared with the control group. No statistically significant differences were observed between the 2 treatment groups., Conclusions: These findings suggest that modified and conventional facemask therapy with expansion have significant cranial flexion effects on the dynamic measurements of natural head position. Additionally, the modified facemask procedure showed significant effects on the orofacial airway dimensions compared with the initial values and the values of the untreated controls., (Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)
- Published
- 2011
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11. Urrets-Zavalia syndrome following iatrogenic pupil dilation in eyes with pigment dispersion.
- Author
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Mocan MC, Bozkurt B, Irkec M, and Orhan M
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- Adult, Anterior Chamber pathology, Atrophy, Cyclopentolate adverse effects, Cyclopentolate therapeutic use, Dexamethasone adverse effects, Dexamethasone therapeutic use, Female, Gonioscopy, Humans, Iatrogenic Disease, Intraocular Pressure, Male, Microscopy, Acoustic, Syndrome, Uveitis, Anterior drug therapy, Exfoliation Syndrome complications, Glaucoma, Open-Angle etiology, Iris pathology, Mydriasis etiology, Pupil drug effects
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- 2009
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12. Relationship between static natural head position and head position measured during walking.
- Author
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Usumez S, Uysal T, Orhan M, and Soganci E
- Subjects
- Adult, Electronics instrumentation, Female, Head Movements physiology, Humans, Male, Signal Processing, Computer-Assisted instrumentation, Head anatomy & histology, Posture physiology, Walking physiology
- Abstract
Introduction: The aim of this project was to determine whether there is a statistically significant difference between the means of static and dynamic (measured during walking) measurements of head posture., Methods: The sample consisted of 50 subjects, 25 women and 25 men, 20 to 25 years of age. None had a history of orthodontic treatment, head or neck injury, or nasal breathing problems, and none wore eyeglasses to correct vision. Static measurement of head position was recorded by using the self-balance position. Dynamic measurements of head position were made with an inclinometer device with the subject walking in a relaxed manner for 5 minutes. The data, measured in degrees, were stored in a pocket data logger. Recorded static and dynamic head posture data were transferred to a computer for analysis. The means of the measurements were statistically compared with the t test (alpha = .05). The mean walking head position was tipped forward relative to the mean static head position., Results: The mean value of static position minus walking head position measurements was +4.60 degrees . The differences between the 2 recordings were statistically significant (P < .001)., Conclusions: Static and walking head position measurements are not interchangeable. Therefore, it might be advisable to use the mean dynamic measurement of head position to represent natural head position for positioning when taking case records such as lateral and posteroanterior cephalograms, clinical extraoral photography, or 3-dimensional imaging.
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- 2006
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13. Reproducibility of natural head position measured with an inclinometer.
- Author
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Uşümez S and Orhan M
- Subjects
- Adolescent, Adult, Female, Follow-Up Studies, Head Movements, Humans, Male, Posture, Reproducibility of Results, Statistics as Topic, Statistics, Nonparametric, Head anatomy & histology
- Abstract
Sagittal (pitch) and transversal (roll) natural head position (NHP) was measured once in 20 subjects, 18 to 24 years of age, with an inclinometer; the measurements were repeated 2 years later. The method error (reproducibility) after 2 years was 1.1 degrees for sagittal and transversal measurements. The mean change in NHP measurement was -0.3 degrees for both measurements, and the variance was 1.21 degrees (= 1.1(2)).
- Published
- 2003
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14. Laser etching of enamel for direct bonding with an Er,Cr:YSGG hydrokinetic laser system.
- Author
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Uşümez S, Orhan M, and Uşümez A
- Subjects
- Acid Etching, Dental, Bicuspid, Chromium, Dental Debonding, Dental Stress Analysis, Erbium, Humans, Kinetics, Materials Testing, Random Allocation, Shear Strength, Stainless Steel, Statistics, Nonparametric, Surface Properties radiation effects, Water, Zinc Phosphate Cement, Dental Bonding instrumentation, Dental Enamel radiation effects, Lasers, Orthodontic Brackets
- Abstract
Irradiation of enamel with laser energy changes the physical and chemical characteristics of the enamel surface, and these alterations hold promise for the conditioning of enamel for bonding procedures. This laboratory study examined the influence of laser irradiation of enamel at 2 different power settings with an erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) hydrokinetic laser system (Millennium System, Biolase Technology, Inc; San Clemente, Calif) on the shear bond strength of orthodontic appliances and compared these with that of acid-etching. The prepared surfaces of 40 noncarious, intact, extracted premolars were exposed to laser energy: 20 teeth at 2-W setting (5.6 J/cm(2)) and 20 teeth at 1-W setting (2.7 J/cm(2)) of the commercial laser unit. Twenty teeth were etched with 37% orthophosphoric acid. Brackets were bonded with an orthodontic no-mix adhesive, and shear bond strength was determined with a universal testing machine. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Etched and restored surfaces of an acid-etched tooth and a 2-W laser-irradiated tooth were examined with scanning electron microscopy (SEM). Laser treatment under 2 W resulted in bond strengths of 7.11 +/- 4.56 megapascals (MPa), which was not significantly different from that of acid etching (8.23 +/- 2.30 MPa). Laser irradiation at 1 W resulted in bond strengths of 5.64 +/- 3.19 MPa, which was significantly different from that of acid etching (P <.05). However, large SD and coefficient of variation values of both laser groups made reliability of this method as an enamel conditioner questionable. Scanning electron microscopy studies of the restored irradiated surfaces showed good surface characteristics, whereas the lased surface was still more irregular than the restored acid-etched sample. Although laser devices are effectively used in some other areas of dentistry, enamel conditioning with an Er,Cr:YSGG laser cannot be considered a successful alternative to the conventional methods of increasing bond strengths to enamel.
- Published
- 2002
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15. Inclinometer method for recording and transferring natural head position in cephalometrics.
- Author
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Uşümez S and Orhan M
- Subjects
- Adolescent, Adult, Eyeglasses, Female, Humans, Male, Reproducibility of Results, Cephalometry instrumentation, Head physiology, Head Movements, Posture
- Abstract
The purposes of this study were (1) to construct a device to record natural head position and transfer it to the cephalostat, (2) to assess its clinical use, and (3) to evaluate the reproducibility of lateral cephalograms taken with the device. The device, incorporated into a pair of eyeglass frames, included 2 tilt sensors to measure pitch and roll of the head. The natural head positions of 20 subjects were established 10 times by self balance and mirror position, recorded with the device, and reproduced in the cephalostat by using the average of these 10 measurements. Three lateral cephalograms were obtained in this manner at 30-minute intervals. The first 2 films were made with the subject wearing the device to assess the reproducibility of the recorded position in the cephalostat by the inclinometer. During exposure of the third film, the device was not worn, and this film was used to determine the stability of the established position when the inclinometer was removed. The results revealed method errors of 0.6 degrees (SD, 0.9) between the first 2 sets of radiographs with a correlation coefficient of 0.985. Method errors between the first and third and the second and third sets were 0.6 degrees (SD, 0.8) and 0.7 degrees (SD, 1), respectively, with correlation coefficients of 0.989 and 0.982. The reproducibility of the method was high, and the system was clinically practical for both recording and transferring natural head position in cephalometrics. This technique should make it possible to measure and reproduce head position accurately. Minimizing the size of the device, making it radiolucent, and integrating it into the radiographic device will make it more versatile and decrease error.
- Published
- 2001
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16. Intraoperative mitomycin C for pterygium surgery.
- Author
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Caliskan S, Orhan M, and Irkeç M
- Subjects
- Cell Division drug effects, Chemotherapy, Adjuvant, Fibroblasts drug effects, Humans, Intraoperative Care, Ophthalmic Solutions therapeutic use, Secondary Prevention, Mitomycin therapeutic use, Pterygium drug therapy, Pterygium surgery
- Published
- 1999
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17. "En masse" retraction of maxillary anterior teeth with anterior headgear.
- Author
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Güray E and Orhan M
- Subjects
- Adolescent, Bicuspid surgery, Cephalometry, Cuspid, Female, Humans, Incisor, Maxilla, Orthodontic Brackets, Orthodontic Wires, Orthodontics, Corrective methods, Tooth Extraction, Extraoral Traction Appliances, Malocclusion, Angle Class II therapy
- Abstract
In the treatment of the first premolar extraction cases with certain techniques, incisor retraction is realized after canine distalization. In maximum anchorage cases, retraction of anterior segments require more posterior anchorage. This treatment concept is still valid, however, the difficult anchorage control is considered a major drawback. The purpose of this study is to introduce our technique for the "en masse" retraction of maxillary anterior teeth after first premolar extraction and discuss its effects. The technique consists of the application of extraoral traction on canines, followed by banding of maxillary anterior teeth, to form them as a mass. Advantages of our mechanics are as follows: (1) Anterior headgear may have the advantage of retracting anterior teeth with minimum strain on posterior anchorage. (2) The adjustability of the outer bow in relation to the premaxilla's center of resistance, provides effective desired movements. (3) Intrusion and torque control are achieved in the course of anterior segment retraction.
- Published
- 1997
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18. Selçuk type headgear-timer (STHT).
- Author
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Güray E and Orhan M
- Subjects
- Humans, Patient Compliance, Time, Extraoral Traction Appliances, Orthodontic Appliance Design instrumentation
- Abstract
The Selçuk type headgear-timer (STHT) is described and tested under laboratory conditions first and then in a controlled patient study. The timing device was compared with real time measurements for 4 months. Accuracy was determined to be absolute (100%). The STHT was determined to be independent of force variables, easy to construct, rugged, and inexpensive. In the clinical test, 10 patients were instructed to wear the extraoral appliance for 16 hours a day. After a 2-month treatment period, the timing mechanisms were introduced to the patients and a subsequent 2-month treatment period was initiated. At the end of the second period, headgear wear was increased 26%. This significant improvement in patient compliance with the STHT timing device, attached to a standard breakaway type headgear, has the likelihood of enhancing treatment results. A foolproof method of assessing actual duration of wear is now available.
- Published
- 1997
- Full Text
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