ZusammenfassungMit dem Ziel, für die Polizistinnen und Polizisten im Wechselschichtdienst (WSD) eine Reduktion potenzieller gesundheitlicher Belastungen zu ermöglichen und eine Verbesserung der ...Vereinbarkeit von Beruf und Privatleben zu erreichen, wurde in der Polizei Hamburg eine neue Dienstzeitregelung (DZR) entwickelt. Das neue Schichtsystem umfasst im Vergleich zur bestehenden DZR 14 statt vier 12-Stunden-Schichten in 8 Wochen, gleichzeitig aber auch 14 anstelle von 2 freien Tagen. Die neue DZR wurde in einer einjährigen Pilotphase in 6 Polizeikommissariaten (PKs) erprobt, die zuvor bei einer Abstimmung einen Zwei-Drittel-Mehrheitsbeschluss für die Teilnahme erzielten. Die Vergleichsgruppe bestand aus 17 nichtpilotierenden PKs. Für eine Prä-post-Analyse wurden vor Beginn der Pilotierung in einem umfassenden Fragebogen neben anderen Parametern die Erwartungen in Bezug auf die Umsetzung im Alltag, die Vereinbarkeit mit dem Privatleben und die Gesundheit erfasst. Nach einem Jahr wurden die Einschätzungen zu den entsprechenden Aspekten erhoben. Vor Beginn der Pilotphase (T0) nahmen 1151 (72,7 %) von insgesamt 1583 im WSD Beschäftigten an der Befragung teil, nach einem Jahr (T1) 74,3 % (1122 von 1511). In beiden Gruppen wurden zu beiden Zeitpunkten die freien Tage und bessere Regenerationsmöglichkeiten als führende Gründe für die Befürwortung der neuen DZR angegeben. Zu T0 erwarteten 16,5 % aus den pilotierenden PKs eine einfache Anpassung des privaten Alltags an die neue DZR, in T1 gaben 36,9 % an, dass diese Anpassung in der einjährigen Pilotphase leicht umzusetzen war. Eine positive Auswirkung auf die allgemeine Gesundheit berichteten 22,1 % der Frauen und 32,7 % der Männer nach der Pilotphase. Die Erwartung an eine verbesserte Regeneration stand zu Beginn der Pilotierung deutlich im Fokus der Beschäftigten. In den 6 pilotierenden PKs wurde die veränderte Schichtplangestaltung mehrheitlich positiv bewertet.
Objectives
Research across many fields of medicine now points towards the clinical advantages of combining regenerative procedures with platelet-rich fibrin (PRF). This systematic review aimed to ...gather the extensive number of articles published to date on PRF in the dental field to better understand the clinical procedures where PRF may be utilized to enhance tissue/bone formation.
Materials and methods
Manuscripts were searched systematically until May 2016 and separated into the following categories: intrabony and furcation defect regeneration, extraction socket management, sinus lifting procedures, gingival recession treatment, and guided bone regeneration (GBR) including horizontal/vertical bone augmentation procedures. Only human randomized clinical trials were included for assessment.
Results
In total, 35 articles were selected and divided accordingly (kappa = 0.94). Overall, the use of PRF has been most investigated in periodontology for the treatment of periodontal intrabony defects and gingival recessions where the majority of studies have demonstrated favorable results in soft tissue management and repair. Little to no randomized clinical trials were found for extraction socket management although PRF has been shown to significantly decrease by tenfold dry sockets of third molars. Very little to no data was available directly investigating the effects of PRF on new bone formation in GBR, horizontal/vertical bone augmentation procedures, treatment of peri-implantitis, and sinus lifting procedures.
Conclusions
Much investigation now supports the use of PRF for periodontal and soft tissue repair. Despite this, there remains a lack of well-conducted studies demonstrating convincingly the role of PRF during hard tissue bone regeneration. Future human randomized clinical studies evaluating the use of PRF on bone formation thus remain necessary.
Clinical relevance
PRF was shown to improve soft tissue generation and limit dimensional changes post-extraction, with little available data to date supporting its use in GBR.
Guided bone regeneration (GBR) is commonly used in combination with the installment of titanium implants. The application of a membrane to exclude non‐osteogenic tissues from interfering with bone ...regeneration is a key principle of GBR. Membrane materials possess a number of properties which are amenable to modification. A large number of membranes have been introduced for experimental and clinical verification. This prompts the need for an update on membrane properties and the biological outcomes, as well as a critical assessment of the biological mechanisms governing bone regeneration in defects covered by membranes. The relevant literature for this narrative review was assessed after a MEDLINE/PubMed database search. Experimental data suggest that different modifications of the physicochemical and mechanical properties of membranes may promote bone regeneration. Nevertheless, the precise role of membrane porosities for the barrier function of GBR membranes still awaits elucidation. Novel experimental findings also suggest an active role of the membrane compartment per se in promoting the regenerative processes in the underlying defect during GBR, instead of being purely a passive barrier. The optimization of membrane materials by systematically addressing both the barrier and the bioactive properties is an important strategy in this field of research.
Aim
To review the knowledge on the mechanisms controlling membrane–host interactions in guided bone regeneration (GBR) and investigate the possible role of GBR membranes as bioactive compartments in ...addition to their established role as barriers.
Materials and Methods
A narrative review was utilized based on in vitro, in vivo and available clinical studies on the cellular and molecular mechanisms underlying GBR and the possible bioactive role of membranes.
Results
Emerging data demonstrate that the membrane contributes bioactively to the regeneration of underlying defects. The cellular and molecular activities in the membrane are intimately linked to the promoted bone regeneration in the underlying defect. Along with the native bioactivity of GBR membranes, incorporating growth factors and cells in membranes or with graft materials may augment the regenerative processes in underlying defects.
Conclusion
In parallel with its barrier function, the membrane plays an active role in hosting and modulating the molecular activities of the membrane‐associated cells during GBR. The biological events in the membrane are linked to the bone regenerative and remodelling processes in the underlying defect. Furthermore, the bone‐promoting environments in the two compartments can likely be boosted by strategies targeting both material aspects of the membrane and host tissue responses.
Biomaterials with suitable surface modification strategies are contributing significantly to the rapid development of the field of bone tissue engineering. Despite these encouraging results, ...utilization of biomaterials is poorly translated to human clinical trials potentially due to lack of knowledge about the interaction between biomaterials and the body defense mechanism, the "immune system". The highly complex immune system involves the coordinated action of many immune cells that can produce various inflammatory and anti-inflammatory cytokines. Besides, bone fracture healing initiates with acute inflammation and may later transform to a regenerative or degenerative phase mainly due to the cross-talk between immune cells and other cells in the bone regeneration process. Among various immune cells, macrophages possess a significant role in the immune defense, where their polarization state plays a key role in the wound healing process. Growing evidence shows that the macrophage polarization state is highly sensitive to the biomaterial's physiochemical properties, and advances in biomaterial research now allow well controlled surface properties. This review provides an overview of biomaterial-mediated modulation of the immune response for regulating key bone regeneration events, such as osteogenesis, osteoclastogenesis, and inflammation, and it discusses how these strategies can be utilized for future bone tissue engineering applications.
The identification of stem cells and growth factors as well as the development of biomaterials hold great promise for regenerative medicine applications. However, the therapeutic efficacy of ...regenerative therapies can be greatly influenced by the host immune system, which plays a pivotal role during tissue repair and regeneration. Therefore, understanding how the immune system modulates tissue healing is critical to design efficient regenerative strategies. While the innate immune system is well known to be involved in the tissue healing process, the adaptive immune system has recently emerged as a key player. T-cells, in particular, regulatory T-cells (Treg), have been shown to promote repair and regeneration of various organ systems. In this review, we discuss the mechanisms by which Treg participate in the repair and regeneration of skeletal and heart muscle, skin, lung, bone, and the central nervous system.
Dental, oral, and craniofacial (DOC) regenerative medicine aims to repair or regenerate DOC tissues including teeth, dental pulp, periodontal tissues, salivary gland, temporomandibular joint (TMJ), ...hard (bone, cartilage), and soft (muscle, nerve, skin) tissues of the craniofacial complex. Polymeric materials have a broad range of applications in biomedical engineering and regenerative medicine functioning as tissue engineering scaffolds, carriers for cell-based therapies, and biomedical devices for delivery of drugs and biologics. The focus of this review is to discuss the properties and clinical indications of polymeric scaffold materials and extracellular matrix technologies for DOC regenerative medicine. More specifically, this review outlines the key properties, advantages and drawbacks of natural polymers including alginate, cellulose, chitosan, silk, collagen, gelatin, fibrin, laminin, decellularized extracellular matrix, and hyaluronic acid, as well as synthetic polymers including polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), poly (ethylene glycol) (PEG), and Zwitterionic polymers. This review highlights key clinical applications of polymeric scaffolding materials to repair and/or regenerate various DOC tissues. Particularly, polymeric materials used in clinical procedures are discussed including alveolar ridge preservation, vertical and horizontal ridge augmentation, maxillary sinus augmentation, TMJ reconstruction, periodontal regeneration, periodontal/peri-implant plastic surgery, regenerative endodontics. In addition, polymeric scaffolds application in whole tooth and salivary gland regeneration are discussed.
Chitosan is a chitin-derived biopolymer that has shown great potential for tissue regeneration and controlled drug delivery. It has numerous qualities that make it attractive for biomedical ...applications such as biocompatibility, low toxicity, broad-spectrum antimicrobial activity, and many others. Importantly, chitosan can be fabricated into a variety of structures including nanoparticles, scaffolds, hydrogels, and membranes, which can be tailored to deliver a desirable outcome. Composite chitosan-based biomaterials have been demonstrated to stimulate in vivo regeneration and the repair of various tissues and organs, including but not limited to, bone, cartilage, dental, skin, nerve, cardiac, and other tissues. Specifically, de novo tissue formation, resident stem cell differentiation, and extracellular matrix reconstruction were observed in multiple preclinical models of different tissue injuries upon treatment with chitosan-based formulations. Moreover, chitosan structures have been proven to be efficient carriers for medications, genes, and bioactive compounds since they can maintain the sustained release of these therapeutics. In this review, we discuss the most recently published applications of chitosan-based biomaterials for different tissue and organ regeneration as well as the delivery of various therapeutics.
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