Search results for "Poly(methyl methacrylate)"
showing 6 items of 26 documents
Physicochemical Surface Properties of Various Intraocular Lenses
2001
<i>Purpose:</i> It is of major interest to understand how intraocular lens (IOL) surfaces interact with aqueous humor or tissues after implantation. Important parameters to describe the physicochemical surface properties are the contact angle and critical surface tension. Therefore, we performed measurements of the contact angle and critical surface tension of several commercially available IOLs. <i>Setting:</i> Department of Ophthalmology, Johannes Gutenberg University, Mainz, University Eye Hospital, Tübingen, and Max Planck Institute for Polymer Research, Mainz, Germany. <i>Methods:</i> A total of 17 commercially available standard quality IOL types (6…
Silver-loaded nanoparticles affect ex-vivo mechanical behavior and mineralization of dentin
2019
Background: The aim was to evaluate the effect of silver loaded nanoparticles (NPs) application on the triboscopic, crystallographic and viscoelastic properties of demineralized dentin. Polymethylmetacrylate-based NPs and Ag loaded NPs were applied on demineralized dentin. Material and Methods: Treated and untreated surfaces were probed by a nanoindenter to test viscoelasticity, and by atomic force microscopy to test nanoroughness and collagen fibril diameter. X-ray diffraction and transmission electron microscopy through selected area diffraction and bright-field imaging were also used. Results: Dentin treated with Ag-NPs attained the lowest complex modulus, and the highest tan delta value…
Endoscopic treatment of gastroesophageal reflux disease.
2005
Gastroesophageal reflux disease is a common chronic disorder which has a severe effect on the patient's quality of life. In view of the high cost of medical therapy and the limitations of surgery, a variety of endoscopic techniques have been developed for the treatment of this condition, and these have shown apparently encouraging results, at least in the short term. However, promising results have been obtained in only around two-thirds of patients over a short-term follow-up period of about 6 months. Moreover, several inconsistencies have emerged between the efficacy of this form of treatment in improving symptoms and quality of life and a lack of improvement of objective parameters, such…
Spring constants of capsular tension rings.
2004
Purpose To determine the spring constants of several types of capsular tension rings (CTRs). Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Methods Fourteen models of CTRs provided by 9 companies were tested; all were 11.0 mm in diameter. The CTRs were positioned in a special retainer of a material-testing machine and compressed at a constant speed of 10.0 mm per minute. The distance and force values were recorded, and each CTR model was tested 3 times using a new specimen each time. The resulting measurements were used to calculate a mean spring constant for each CTR model. Results All tested CTRs showed linear proportionality between force and compress…
Ergebnisse nach Implantation einer Worst Iris Claw Lens zur Korrektur der hohen Myopie
2001
Fragestellung. Ziel dieser prospektiven klinischen Studie war die Erfassung der Refraktion, des korrigierten Visus und des Vorderkammerreizzustandes nach Implantation einer Worst Iris Claw Lens zur Korrektur der hohen Myopie. Patienten und Methode. Von Dezember 1996 bis Februar 1999 wurde bei insgesamt 44 phaken Augen von 28 Patienten eine Worst Iris Claw Lens implantiert. Es folgte eine Nachbeobachtungszeit von 6 Wochen bzw. 6 Monaten. Ergebnisse. Das mittlere praoperative spharische Aquivalent betrug −17,35±3,57 dpt. Sechs Monate postoperativ lag die Refraktion bei 79% der Augen im Intervall von ±1,0 dpt von der Zielrefraktion entfernt. Der mittlere korrigierte Visus stieg von praoperativ…
Methotrexate-Loaded Polymethylmethacrylate Bone Cement for Local Bone Metastasis Therapy: Pilot Animal Study in the Rabbit Patellar Groove
2008
Local chemotherapy is an option in bone metastasis treatment. On the other hand, evaluation of side effects on bone is a difficult issue in drug development and biomaterials research. Most animal models to date are inappropriate or not feasible. Rabbits are an alternative to other bigger mammals and have an appropriate bone structure compared to rats and mice. The patellar groove model of the rabbit offers a standardized and sensitive model to evaluate bone-compromising drug effects. We tested the system with a reproducible polymethacrylate implant as carrier and loaded this system with methotrexate. Three methotrexate concentrations were used in the test samples (250 mg, 1 g and 4 g per 40…