Efficacy of a triclosan formula in controlling early subgingival biofilm formation: a randomized trial

The aim of this study was to determine the efficacy of rinses with slurries of a dentifrice containing triclosan (TCS), as compared with rinses with slurries from a control dentifrice, in controlling early subgingival biofilm formation. A double-blind, randomized and cross-over clinical trial was designed, and 26 dental students were included. In the first period, participants were randomized to rinse with a TCS slurry or a control slurry, in a 12 h interval, and to refrain from mechanical cleaning. A Plaque Free Zone Index was assessed at 24 h, 48 h, 72 h and 96 h. After a washout period of 10 days, the second experimental period was conducted, following the same protocol as the first period, except that the slurry groups were switched. Use of the TCS slurry resulted in a significantly higher percentage of plaque-free surfaces, both at 24 h and at 72 h (p < 0.01). In the of 48-72 h interval, the triclosan slurry showed a lower percentage of sites converted to a score of 2 (38.1% for the test versus 40% for the control product, p = 0.015). In conclusion, rinsing with slurries of dentifrice containing TCS retards the down growth of bacterial biofilms from the supra- to the subgingival environment.The aim of this study was to determine the efficacy of rinses with slurries of a dentifrice containing triclosan (TCS), as compared with rinses with slurries from a control dentifrice, in controlling early subgingival biofilm formation. A double-blind, randomized and cross-over clinical trial was designed, and 26 dental students were included. In the first period, participants were randomized to rinse with a TCS slurry or a control slurry, in a 12 h interval, and to refrain from mechanical cleaning. A Plaque Free Zone Index was assessed at 24 h, 48 h, 72 h and 96 h. After a washout period of 10 days, the second experimental period was conducted, following the same protocol as the first period, except that the slurry groups were switched. Use of the TCS slurry resulted in a significantly higher percentage of plaque-free surfaces, both at 24 h and at 72 h (p < 0.01). In the of 48-72 h interval, the triclosan slurry showed a lower percentage of sites converted to a score of 2 (38.1% for the test versus 40% for the control product, p = 0.015). In conclusion, rinsing with slurries of dentifrice containing TCS retards the down growth of bacterial biofilms from the supra- to the subgingival environment.The aim of this study was to determine the efficacy of rinses with slurries of a dentifrice containing triclosan (TCS), as compared with rinses with slurries from a control dentifrice, in controlling early subgingival biofilm formation. A double-blind, randomized and cross-over clinical trial was designed, and 26 dental students were included. In the first period, participants were randomized to rinse with a TCS slurry or a control slurry, in a 12 h interval, and to refrain from mechanical cleaning. A Plaque Free Zone Index was assessed at 24 h, 48 h, 72 h and 96 h. After a washout period of 10 days, the second experimental period was conducted, following the same protocol as the first period, except that the slurry groups were switched. Use of the TCS slurry resulted in a significantly higher percentage of plaque-free surfaces, both at 24 h and at 72 h (p < 0.01). In the of 48-72 h interval, the triclosan slurry showed a lower percentage of sites converted to a score of 2 (38.1% for the test versus 40% for the control product, p = 0.015). In conclusion, rinsing with slurries of dentifrice containing TCS retards the down growth of bacterial biofilms from the supra- to the subgingival environment.The aim of this study was to determine the efficacy of rinses with slurries of a dentifrice containing triclosan (TCS), as compared with rinses with slurries from a control dentifrice, in controlling early subgingival biofilm formation. A double-blind, randomized and cross-over clinical trial was designed, and 26 dental students were included. In the first period, participants were randomized to rinse with a TCS slurry or a control slurry, in a 12 h interval, and to refrain from mechanical cleaning. A Plaque Free Zone Index was assessed at 24 h, 48 h, 72 h and 96 h. After a washout period of 10 days, the second experimental period was conducted, following the same protocol as the first period, except that the slurry groups were switched. Use of the TCS slurry resulted in a significantly higher percentage of plaque-free surfaces, both at 24 h and at 72 h (p < 0.01). In the of 48-72 h interval, the triclosan slurry showed a lower percentage of sites converted to a score of 2 (38.1% for the test versus 40% for the control product, p = 0.015). In conclusion, rinsing with slurries of dentifrice containing TCS retards the down growth of bacterial biofilms from the supra- to the subgingival environment

Nanoscale 3D structures towards improved cell-chip coupling on microelectrode arrays

The human brain is a highly interconnected system, consisting of about 86 billion neurons,$^{[1]}$ each forming on average 7,000 connections to neighboring cells.$^{[2]}$ While neuroscientists have achieved various breakthroughs elucidating the underlying principles of neuronal communication in the past decades, the goal of an in-depth understanding of the complex events involved in network communication and processes such as learning remains unattained. One approach often employed to reduce the complexity and thereby facilitate high-resolution studies of the cellular interactionis the application of microelectrode arrays (MEAs). They enable the $\textit{in vitro}$ investigation of small neuronal networks, yielding correlated data of the cellular activity with high temporal resolution. However, MEAs suffer from inherently low signal amplitudes due to a loose cell-chip contact and thus insufficient coupling between the cellular signals and the electrode. In the past decade, three dimensional electrode designs have been extensively studied as possible solution for the problem of low signal amplitudes during MEA-based investigations of electrogenic cells. They improve the cell-chip coupling through the establishment of a tighter interface between biology and electronics. However, while many different 3D designs have been suggested in the literature, the requirements for a direct comparison of the recording capabilities yielded by the different structures have so far not been met. The aim of this body of work therefore is the development of an approach allowing for the parallel fabrication of multiple different 3D designs on a single chip and thus parallel testing on the biological system. In the first part of this thesis, electron-beam lithography is employed in conjunction with electrode position for a parallelized preparation of thousands of 3D structures on gold-on-silicon substrates. In this manner, the common 3D geometries as reported in the literature - pillars, hollow pillars, and mushroom-shaped structures - are produced. Furthermore, hollow mushrooms are developed as novel 3D design. The interaction of the structures with both cardiomyocyte-like HL-1 cells as well as rat cortical neurons is investigated. In the second part of this thesis, the developed 3D structures are transferred onto MEAs. A thorough investigation of the galvanization procedure yields parameters that enable the real-time control of the nanoscale structure size during the electrode position process. In this way, 3D electrodes of different shape and size can be prepared on a single MEA and thus be investigated simultaneously with respect to their interaction with electrogenic cells. Electrophysiological studies are performed employing cardiomyocyte-like HL-1 cells as model system. Furthermore, various modifications of the 3D structures are discussed, aiming at improved electrical characteristics for future investigations. In conclusion, this body of work presents a well-controlled process for the preparation of 3D structures on MEAs, thereby facilitating the preparation of multiple different three-dimensional designs on a single chip. This forms the basis for an in-depth characterization of the improvement of the cell-chip coupling yielded by the different 3D designs

Netzwerke der Erkenntnis

Das menschliche Gehirn ist ein Organ größter Komplexität. Trotz weitreichender Fortschritte in den Neuro­wissenschaften bleibt das detaillierte Verständnis der Aktivität und Interaktion dieses komplexen Systems bislang ein unerreichtes Ziel. Ein vielversprechender Versuch, die Signalprozessierung besser zu verstehen, ist die Bioelektronik, die von kleineren neuronalen Netzwerken ausgeht

Efficacy of a triclosan formula in controlling early subgingival biofilm formation : a randomized trial

Abstract: The aim of this study was to determine the efficacy of rinses with slurries of a dentifrice containing triclosan (TCS), as compared with rinses with slurries from a control dentifrice, in controlling early subgingival biofilm formation. A double-blind, randomized and cross-over clinical trial was designed, and 26 dental students were included. In the first period, participants were randomized to rinse with a TCS slurry or a control slurry, in a 12 h interval, and to refrain from mechanical cleaning. A Plaque Free Zone Index was assessed at 24 h, 48 h, 72 h and 96 h. After a washout period of 10 days, the second experimental period was conducted, following the same protocol as the first period, except that the slurry groups were switched. Use of the TCS slurry resulted in a significantly higher percentage of plaque-free surfaces, both at 24 h and at 72 h (p < 0.01). In the of 48-72 h interval, the triclosan slurry showed a lower percentage of sites converted to a score of 2 (38.1% for the test versus 40% for the control product, p = 0.015). In conclusion, rinsing with slurries of dentifrice containing TCS retards the down growth of bacterial biofilms from the supra- to the subgingival environment

MEAs and 3D nanoelectrodes: electrodeposition as tool for a precisely controlled nanofabrication

Microelectrode arrays (MEAs) are gaining increasing importance for the investigation of signaling processes between electrogenic cells. However, efficient cell–chip coupling for robust and long-term electrophysiological recording and stimulation still remains a challenge. A possible approach for the improvement of the cell–electrode contact is the utilization of three-dimensional structures. In recent years, various 3D electrode geometries have been developed, but we are still lacking a fabrication approach that enables the formation of different 3D structures on a single chip in a controlled manner. This, however, is needed to enable a direct and reliable comparison of the recording capabilities of the different structures. Here, we present a method for a precisely controlled deposition of nanoelectrodes, enabling the fabrication of multiple, well-defined types of structures on our 64 electrode MEAs towards a rapid-prototyping approach to 3D electrodes

Printed microelectrode arrays on soft materials: from PDMS to hydrogels

Microelectrode arrays (MEAs) provide promising opportunities to study electrical signals in neuronal and cardiac cell networks, restore sensory function, or treat disorders of the nervous system. Nevertheless, most of the currently investigated devices rely on silicon or polymer materials, which neither physically mimic nor mechanically match the structure of living tissue, causing inflammatory response or loss of functionality. Here, we present a new method for developing soft MEAs as bioelectronic interfaces. The functional structures are directly deposited on PDMS-, agarose-, and gelatin-based substrates using ink-jet printing as a patterning tool. We demonstrate the versatility of this approach by printing high-resolution carbon MEAs on PDMS and hydrogels. The soft MEAs are used for in vitro extracellular recording of action potentials from cardiomyocyte-like HL-1 cells. Our results represent an important step toward the design of next-generation bioelectronic interfaces in a rapid prototyping approach

Efficacy of a triclosan formula in controlling early subgingival biofilm formation : a randomized trial

Abstract: The aim of this study was to determine the efficacy of rinses with slurries of a dentifrice containing triclosan (TCS), as compared with rinses with slurries from a control dentifrice, in controlling early subgingival biofilm formation. A double-blind, randomized and cross-over clinical trial was designed, and 26 dental students were included. In the first period, participants were randomized to rinse with a TCS slurry or a control slurry, in a 12 h interval, and to refrain from mechanical cleaning. A Plaque Free Zone Index was assessed at 24 h, 48 h, 72 h and 96 h. After a washout period of 10 days, the second experimental period was conducted, following the same protocol as the first period, except that the slurry groups were switched. Use of the TCS slurry resulted in a significantly higher percentage of plaque-free surfaces, both at 24 h and at 72 h (p < 0.01). In the of 48-72 h interval, the triclosan slurry showed a lower percentage of sites converted to a score of 2 (38.1% for the test versus 40% for the control product, p = 0.015). In conclusion, rinsing with slurries of dentifrice containing TCS retards the down growth of bacterial biofilms from the supra- to the subgingival environment