Prognose und Prognosefaktoren enossaler Implantate im bestrahlten Kiefer

Zusammenfassung Einleitung: Die kaufunktionelle Wiederherstellung nach Kopf-Hals-Bestrahlung ist gegenuber anderen Tumorpatienten durch Strahlenkaries, Radioxerostomie und Osteoradionekroserisiko zusatzlich limitiert. Es wurde der Frage der Implantatprognose und potentieller Prognosefaktoren im bestrahlten Kiefer nachgegangen. Material und Methode: Die retrospektive Studie erfaste von 1988–1997 197 Implantate (47 Patienten). Die Implantatprognose wurde durch Uberlebenszeitanalyse (Kaplan-Meier) bestimmt, wobei implantatunabhangige Verluste zensiert wurden. Auserdem erfolgte eine Gruppenbildung nach potentiell die Prognose beeinflussenden Parametern. Grupppenunterschiede in den Uberlebensrat…

Cytotoxicity of Metal and Semiconductor Nanoparticles Indicated by Cellular Micromotility

In the growing field of nanotechnology, there is an urgent need to sensitively determine the toxicity of nanoparticles since many technical and medical applications are based on controlled exposure to particles, that is, as contrast agents or for drug delivery. Before the in vivo implementation, in vitro cell experiments are required to achieve a detailed knowledge of toxicity and biodegradation as a function of the nanoparticles' physical and chemical properties. In this study, we show that the micromotility of animal cells as monitored by electrical cell-substrate impedance analysis (ECIS) is highly suitable to quantify in vitro cytotoxicity of semiconductor quantum dots and gold nanorods…

Evolutionary White-Box Software Test with the EvoTest Framework: A Progress Report

Evolutionary white-box software testing has been extensively researched but is not yet applied in industry. In order to investigate the reasons for this, we evaluated a prototype version of a tool, representing the state-of-the-art for evolutionary structural testing, which is targeted at industrial use. The focus was on the applicability of the structural test tool in the industrial context and not on assessment of the test cases generated. Four case studies, each consisting of an embedded software module from the automotive industry implemented in the C language, were evaluated with the tool. The case studies had to be customized to cope with the limitations of the tool and in all, test c…

Dynamics of human cancer cell lines monitored by electrical and acoustic fluctuation analysis.

Early determination of the metastatic potential of cancer cells is a crucial step for successful oncological treatment. Besides the remarkable progress in molecular genomics- or proteomics-based diagnostics, there is a great demand for in vitro biosensor devices that allow rapid and selective detection of the invasive properties of tumor cells. Here, the classical cancer cell motility in vitro assays for migration and invasion relying on Boyden chambers are compared to a real-time biosensor that analyzes the dynamic properties of adherent cells electro-acoustically with a time resolution on the order of seconds. The sensor relies on the well-established quartz crystal microbalance technique…

Toxicity of gold-nanoparticles: Synergistic effects of shape and surface functionalization on micromotility of epithelial cells

Nanoparticle exposure is monitored by a combination of two label-free and non-invasive biosensor devices which detect cellular shape and viscoelasticity (quartz crystal microbalance), cell motility and the dynamics of epithelial cell-cell contacts (electric cell-substrate impedance sensing). With these tools we have studied the impact of nanoparticle shape on cellular physiology. Gold (Au) nanoparticles coated with CTAB were synthesized and studied in two distinct shapes: Spheres with a diameter of (43 ± 4) nm and rods with a size of (38 ± 7) nm × (17 ± 3) nm. Dose-response experiments were accompanied by conventional cytotoxicity tests as well as fluorescence and dark-field microscopy to v…

Cell motility probed by noise analysis of thickness shear mode resonators.

The quartz crystal microbalance (QCM) technique is an emerging bioanalytical tool to study the behavior of animal cells in vitro. Due to the high interfacial sensitivity of thickness shear mode (TSM) resonators it is possible to monitor the formation and breakage of cell-matrix interactions and changes in viscoelasticity of the cell bodies, as well as minute cell volume alterations by the time course of their resonance frequency even with millisecond time resolution. We found that mammalian MDCK-II cells grown on TSM resonators impose characteristic fluctuations on the resonance frequency, which are a quantitative indicator for dynamic activities of the cells on the surface and report on th…

Der Oberkiefer – das schlechtere Implantatlager?

In the maxilla, it is sometimes necessary to use implants to achieve a good prosthetic result. However, an increased failure rate of maxillary implants seems to be a common clinical experience. This experience was investigated in a retrospective statistical analysis. In a retrospective study of 665 patients between 1987 and 1997, 2484 implants were examined. The implants in the upper jaw were compared to those in the lower jaw. Implants with and without autogenous bone grafts and fixtures in patients with alveolar ridge atrophy, tumor, or trauma were explored. In particular, the data obtained from the orthopantomograms after completion of the prosthetic superstructures were controlled for p…

Industrial Scaled Automated Structural Testing with the Evolutionary Testing Tool

Evolutionary testing has been researched and promising results have been presented. However, evolutionary testing has remained predominately a research-based activity not practiced within industry. Although attempts have been made, such as Daimler's Evolutionary Structural Test (EST) prototype, until now, no such tool has been suitable for industrial adoption. The European project EvoTest (IST-33472) team has been working from 2006 till2009 to improve this situation. This paper describes the final version of the Evolutionary Testing Framework (ETF) resulting from the EvoTest project. In specific we will present the EvoTest Structural Testing tool for fully automatic structural testing that …

Adhesion of liposomes: a quartz crystal microbalance study

Three different systems are presented, exploring the adhesion of liposomes mediated by electrostatic and lipid–protein interactions as well as molecular recognition of ligand receptor pairs. Liposomes are frequently used to gain insight into the complicated processes involving adhesion and subsequent events such as fusion and fission mainly triggered by specific proteins. We combined liposome technology with the quartz crystal microbalance (QCM) technique as a powerful tool to study the hidden interface between the membrane and functionalized surface. Electrostatic attraction and molecular recognition were employed to bind liposomes to the functionalized quartz crystal. The QCM was used to …

Ten-Year Retrospective Follow-Up Study of the TiOblast™ Dental Implant

Purpose: Long-term results in the clinical outcome of different implant systems, including high patient numbers and a long follow-up time, are rare. This retrospective study evaluated the cumulative survival rate of a self-tapping, cylindrical implant system with a conical implant-abutment connection after 10 years of prosthetic loading. Materials and Methods: A total of 516 TiOblast™ implants (Astra Tech AB, Molndal, Sweden) were placed in 108 patients. The patients were treated in the Department of Oral and Maxillofacial Surgery, Johannes Gutenberg University, Mainz, Germany, between September 1994 and May 2005. The main indications for implantation were the treatment of edentulous mandib…

Membrane Stiffness of Animal Cells Challenged by Osmotic Stress