90 research outputs found

    Relationships between different tooth shapes and patients periodontal phenotype

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    Background and Objective: The purpose of the present study was to establish whether any correlation exists between tooth shapes and patient-related factors such as gingival and periodontal characteristics. Material and Methods: Clinical measurements, including the width and the height of maxillary central incisor crowns, the apico incisal height of the keratinized mucosa (KM), the buccal gingival thickness (GT), the depth of the sulcus (SD), the bone-sounding depth (BS) and the height of the interproximal maxillary central papilla (Ph), were investigated in 50 healthy individuals. These individuals were then divided into three groups based on the shape of their maxillary central incisor crowns: triangular; square; or square-tapered. The three groups were analyzed to determine any significant differences among the groups in the values obtained for clinical measurements. Results: There were no significant differences among the three groups in terms of the SD (p = 0.11) or the BS (p = 0.54), whilst statistically significant differences were observed for the KM (p < 0.001), the GT (p = 0.012) and the Ph (p < 0.001). Conclusion: The results of this study indicate that different tooth shapes are associated with significantly different values for the extent of the KM, its bucco-lingual thickness and the height of the interproximal maxillary central papilla

    Relationships between different tooth shapes and patients periodontal phenotype

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    Background and Objective: The purpose of the present study was to establish whether any correlation exists between tooth shapes and patient-related factors such as gingival and periodontal characteristics. Material and Methods: Clinical measurements, including the width and the height of maxillary central incisor crowns, the apico incisal height of the keratinized mucosa (KM), the buccal gingival thickness (GT), the depth of the sulcus (SD), the bone-sounding depth (BS) and the height of the interproximal maxillary central papilla (Ph), were investigated in 50 healthy individuals. These individuals were then divided into three groups based on the shape of their maxillary central incisor crowns: triangular; square; or square-tapered. The three groups were analyzed to determine any significant differences among the groups in the values obtained for clinical measurements. Results: There were no significant differences among the three groups in terms of the SD (p = 0.11) or the BS (p = 0.54), whilst statistically significant differences were observed for the KM (p < 0.001), the GT (p = 0.012) and the Ph (p < 0.001). Conclusion: The results of this study indicate that different tooth shapes are associated with significantly different values for the extent of the KM, its bucco-lingual thickness and the height of the interproximal maxillary central papilla

    Hot-spot consensus of fluoroquinolone-mediated DNA cleavage by Gram-negative and Gram-positive type II DNA topoisomerases

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    Bacterial DNA gyrase and topoisomerase IV are selective targets of fluoroquinolones. Topoisomerase IV versus gyrase and Gram-positive versus Gram-negative behavior was studied based on the different recognition of DNA sequences by topoisomerase–quinolone complexes. A careful statistical analysis of preferred bases was performed on a large number (>400) of cleavage sites. We found discrete preferred sequences that were similar when using different enzymes (i.e. gyrase and topoisomerase IV) from the same bacterial source, but in part diverse when employing enzymes from different origins (i.e. Escherichia coli and Streptococcus pneumoniae). Subsequent analysis on the wild-type and mutated consensus sequences showed that: (i) Gn/Cn-rich sequences at and around the cleavage site are hot spots for quinolone-mediated strand breaks, especially for E. coli topoisomerases: we elucidated positions required for quinolone and enzyme recognition; (ii) for S. pneumoniae enzymes only, A and T at positions −2 and +6 are discriminating cleavage determinants; (iii) symmetry of the target sequence is a key trait to promote cleavage and (iv) the consensus sequence adopts a heteronomous A/B conformation, which may trigger DNA processing by the enzyme–drug complex

    Using Relational Verification for Program Slicing

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    Program slicing is the process of removing statements from a program such that defined aspects of its behavior are retained. For producing precise slices, i.e., slices that are minimal in size, the program\u27s semantics must be considered. Existing approaches that go beyond a syntactical analysis and do take the semantics into account are not fully automatic and require auxiliary specifications from the user. In this paper, we adapt relational verification to check whether a slice candidate obtained by removing some instructions from a program is indeed a valid slice. Based on this, we propose a framework for precise and automatic program slicing. As part of this framework, we present three strategies for the generation of slice candidates, and we show how dynamic slicing approaches - that interweave generating and checking slice candidates - can be used for this purpose. The framework can easily be extended with other strategies for generating slice candidates. We discuss the strengths and weaknesses of slicing approaches that use our framework

    Low temperature method for the production of calcium phosphate fillers

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    BACKGROUND: Calcium phosphate manufactured samples, prepared with hydroxyapatite, are used as either spacers or fillers in orthopedic surgery, but these implants have never been used under conditions of mechanical stress. Similar conditions also apply with cements. Many authors have postulated that cements are a useful substitute material when implanted in vivo. The aim of this research is to develop a low cristalline material similar to bone in porosity and cristallinity. METHODS: Commercial hydroxyapatite (HAp) and monetite (M) powders are mixed with water and compacted to produce cylindrical samples. The material is processed at a temperature of 37–120 degrees C in saturated steam to obtain samples that are osteoconductive. The samples are studied by X-ray powder diffraction (XRD), Vickers hardness test (HV), scanning electron microscopy (SEM), and porosity evaluation. RESULTS: The X-ray diffractions of powders from the samples show patterns typical of HAp and M powders. After thermal treatment, no new crystal phase is formed and no increase of the relative intensity of the peaks is obtained. Vicker hardness data do not show any relationship with treatment temperature. The total porosity decreases by 50–60% according to the specific thermal treatment. Scanning electron microscopy of the surfaces of the samples with either HAp 80%-M 20% (c) or Hap 50%-M 50% (f), show cohesion of the powder grains. CONCLUSIONS: The dissolution-reprecipitation process is more intesive in manufactured samples (c) and (f), according to Vickers hardness data. The process occurs in a steam saturated environment between 37 degrees and 120 degrees C. (c) (f) manufactured samples show pore dimension distributions useful to cellular repopulation in living tissues

    Implementation considerations for Big Data Analytics (BDA) : a benefit dependency network approach

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    The benefits of Big Data Analytics (BDA) are substantial in instances where organisations manage to successfully implement analytical capabilities. These benefits include improved, data driven decision-making, which can lead to deeper insight into business operations and as a result better performing organisations. Not surprisingly, an increased number of organisations are researching best implementation practices for BDA projects. Similar to software projects, research has shown that many BDA projects fail or do not deliver the business value as promised. To address this issue, the main objective of this research is to identify BDA implementation considerations for new BDA endeavors that will help organisations to align their BDA efforts with their overall business strategy to maximize business value. Based on a Benefit Dependency Network (BDN) model as main theoretical underpinning, a structured literature review was conducted focusing on investment objectives, business benefits, enabling changes and IT enablers when implementing BDA. A BDA implementation requires a holistic approach by considering aspects such as the skills of people which will have an impact on the structure of the organisation, business processes and technology changes to deliver benefits and investment objectives. Each of the domains of the BDN should be considered prior to BDA implementations. The research offers a guideline to organisations implementing BDA, based on the foundation of BDN.http://link.springer.combookseries/558hj2021Informatic
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