77 research outputs found

    Talking about the likelihood of risks:an agent-based simulation of discussion processes in risk workshops

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    Purpose This paper aims to explore drivers of the effectiveness of risk assessments in risk workshops. Design/methodology/approach This study uses an agent-based model to simulate risk assessments in risk workshops. Combining the notions of transactive memory and the ideal speech situation, this study establishes a risk assessment benchmark and then investigates real-world deviations from this benchmark. Specifically, this study models limits to information transfer, incomplete discussions and potentially detrimental group characteristics, as well as interaction patterns. Findings First, limits to information transfer among workshop participants can prevent a correct consensus. Second, increasing the required number of stable discussion rounds before an assessment improves the correct assessment of high but not low likelihood risks. Third, while theoretically advantageous group characteristics are associated with the highest assessment correctness for all risks, theoretically detrimental group characteristics are associated with the highest assessment correctness for high likelihood risks. Fourth, prioritizing participants who are particularly concerned about the risk leads to the highest level of correctness. Originality/value This study shows that by increasing the duration of simulated risk workshops, the assessments change – as a rule – from underestimating to overestimating risks, unraveling a trade-off for risk workshop facilitators. Methodologically, this approach overcomes limitations of prior research, specifically the lack of an assessment and process benchmark, the inability to disentangle multiple effects and the difficulty of capturing individual cognitive processes

    Counterproductive Work Behaviors and Work Climate:The Role of an Ethically Focused Management Control System and Peers’ Self-Focused Behavior

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    The importance of curtailing undesirable behaviors and, ultimately, self-focused work climates in organizations is undeniable. This study examines how management control systems (MCSs), as a crucial part of a firm’s formal ethical infrastructure, can contribute to this objective. We conceptualize an ethically focused MCS as one that communicates ethical values and motivates employees to act accordingly. Our study is based on data from a sample of 120 department managers from 120 different firms. We show that department managers’ perceptions of the extent to which the MCS imposed on them is ethically focused are associated with a reduction in their counterproductive work behaviors (CWBs). We also examine department managers’ perceptions of peer managers’ self-focused behaviors, as a core part of a firm’s informal ethical infrastructure and find that peers’ behaviors are not associated with an increase in CWBs of the department manager. However, we find some evidence that the negative association between an ethically focused MCS and managers’ CWBs is limited when peers act in ways that are more self-focused. Finally, we find that CWBs of department managers are not only relevant in and of themselves, but they translate into more self-focused behaviors of department employees (as manifested in their work climates). Overall, this study suggests that, while including and emphasizing ethical content in the MCS is associated with less CWB and, in turn, with a work climate less focused on self, peer managers’ behaviors are also seemingly important

    The application of bone graft substitutes for alveolar ridge preservation after orthodontic extractions and for augmentation of residual cleft defects

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    The use of bone substitute materials in orthodontics is to be considered prior to orthodontic space closure after tooth extraction during the treatment of marked crowding as well as for treatment of residual defects in cleft-lip-and-palate children. In both cases the common objective is structure preservation or augmentation of the alveolar ridge. The demands to be made on the synthetic bone graft substitute comprise not just complication-free and safe use but also the chance of early tooth movement into the treated defect area with sufficient stability of the new tooth position

    Bone graft substitutes in periodontal and peri-implant bone regeneration

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    Regenerative medicine provides different therapy alternatives alongside gold standard autogenous grafts for the treatment of periodontal or peri-implant osseous defects. Continuing progress in the field of alloplastic bone substitutes has yielded promising solutions to the appropriate indications with the membrane technique either alone or in combination with enamel matrix derivatives. Their clinical outcomes, however, still require critical discussion

    The clinical application of a new synthetic bone grafting material in oral and maxillofacial surgery

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    A novel bone formation material based on hydroxyapatite-xerogel is presented. With the use of the innovative sol-gel technology this material is produced in the low-temperature range by the addition of silicon dioxide; in its structure it mimics to a great extent the natural bone matrix. This results in high osteoconductivity and an osteoprotective effect as well as in complete biodegradation corresponding to bone formation in the course of natural bone remodelling. Two case reports are presented

    The manufacture of synthetic non-sintered and degradable bone grafting substitutes

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    A new synthetic bone grafting substitute (NanoBone®, ARTOSS GmbH, Germany) is presented. This is produced by a new technique, the sol-gel-method. This bone grafting substitute consists of nanocrystalline hydroxyapatite (HA) and nanostructured silica (SiO2). By achieving a highly porous structure good osteoconductivity can be seen. In addition, the material will be completely biodegraded and new own bone is formed. It has been demonstrated that NanoBone® is biodegraded by osteoclasts in a manner comparable to the natural bone remodelling process

    The biodegradation of hydroxyapatite bone graft substitutes in vivo

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    Hydroxyapatite (HA) ceramics are widely used for bone reconstruction. They are osteoconductive and serve as structural scaffolds for the deposition of new bone. Generally, scaffold materials should be degradable as they affect the mechanical properties of the reconstructed bone negatively. Degradation by osteoclasts during the bone remodelling process is desirable but often does not take place. In the current study we analysed by light microscopy the degradation of two granular HA implants in critically sized defects in the mandibula of Goettingen mini-pigs five weeks after implantation. Bio-Oss® consists of sintered bovine bone and NanoBone® is a synthetic HA produced in a sol-gel process in the presence of SiO2. We found that both biomaterials were degraded by osteoclasts with ruffled borders and acid phosphatase activity. The osteoclasts created resorption lacunae and resorptive trails and contained mineral particles. Frequently, resorption surfaces were in direct contact with bone formative surfaces on one granule. Granules, especially of NanoBone®, were also covered by osteoclasts if located in vascularised connective tissue distant from bone tissue. However, this usually occurred without the creation of resorption lacunae. The former defect margins consisted of newly formed bone often without remnants of bone substitutes. Our results show that the degradation of both biomaterials corresponds to the natural bone degradation processes and suggest the possibility of complete resorption during bone remodelling

    Bone functions and the requirements for bone grafts and substitutes in the orofacial region

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    Bone is the largest calcium storage, has distinctive plasticity and adaptability and is part of the supporting tissue. An adequate composition is thus necessary. The bone matrix consists of organic and anorganic structures. Osteoblasts, osteoclasts and osteocytes are responsible for bone formation, resorption and metabolism. The periosteum, endosteum and bone tissue are a functional unit and provide protection, nutrition and growth. Bone is subject to continuous remodelling

    Wound management after the application of bone grafting substitutes in the orofacial region

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    Surgical dressing after the application of bone grafting material depends on the type and size of the defect. A complete and tension-free wound closure has proved to be successful. In this context the infection problem needs special attention. Bone graft substitutes with an adequate surface structure, porosity and chemical properties, in combination with sufficient blood circulation, hold osteoconductive potential. They serve as a guide rail for the osteoblast-induced formation of new bone tissue, which at best may lead to complete replacement of the grafting material
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