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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Risk factors associated with oral candidiasis in elderly diabetic and non-diabetic patients wearing removable acrylic prostheses

Al-Dwairi, Ziad Nawaf January 2001 (has links)
No description available.
72

Dental erosion in Libyan schoolchildren and its association with potential risk factors

Huew, Rasmia January 2010 (has links)
Dental erosion appears to be affecting a growing number of children but there are no data on its prevalence and severity in children or adults in Libya. The aim of this study was to determine the prevalence of dental erosion in Libyan schoolchildren, compare with other countries and to test its association with potential risk factors and dental caries. A crosssectional observational study was carried out in Benghazi, Libya. Ethical approval and permissions were secured from local authorities and written consents obtained from parents/guardians and children. Cluster sampling within schools provided a random sample of 791 12 year-old schoolchildren, mean age 11.7 (SD± 0.31) years (397 boys and 394 girls) attending 36 elementary schools in 15 different districts in Benghazi. This index assesses the area and depth of dental erosion affecting the labial and palatal surfaces of upper permanent incisors and occlusal surfaces of the first permanent molars. Dental caries was assessed using the DMFT and DMFS indices and WHO (1997) criteria. The reproducibility of the study was assessed through the re-examination of 10% of the sample. Associations between dental erosion and caries and the variables under study were investigated through processes of bivariate and multivariate analysis. The statistical significance level was set at 5%. Dental erosion was observed in 40.8% of subjects; erosion into enamel affecting 32.5%, into dentine affecting 8% and into pulp affecting 0.3% of subjects. The prevalence of dental caries was 57.8%. The mean DMFT and DMFS indices were 1.68 (SD± 1.86) and 2.39 (SD± 3.05) for all subjects and 2.90 (SD± 1.56) and 4.14 (SD± 2.97) for subjects with caries experience. Dental erosion was not statistically significantly associated with dental caries. Analysis of the questionnaire survey showed statistically significantly positive associations between the experience of dental erosion and frequency of consumption of fruit-based sugared drinks (p= 0.006) and time taken to consume drinks (p= 0.005) and a statistically significantly negative association between dental erosion and frequency of consumption of tea with milk (p= 0.032). There was a statistically significantly positive association between experience of dental caries and frequency of consumption of fruit-based sugared drinks (p= 0.002) and a statistically significantly negative association between dental caries and the level of fathers’ education (p= 0.015). No statistically significant associations were found between dental erosion or caries and any dietary variable measured through the food diaries with interviews. It is concluded that, the prevalence and severity of dental erosion in 12 year-old children in Benghazi, Libya was in agreement with data reported for the prevalence and severity of dental erosion in European children. The consumption of fruit-based sugared drinks represented the most important risk factor for dental erosion and caries in this sample of Libyan schoolchildren.
73

Adipokines and myeloid cell immune responses in periodontal disease and diabetes

Jaedicke, Katrin Monika January 2010 (has links)
Type 2 diabetes mellitus (T2DM) is a risk factor for periodontal disease, however the pathogenic links between the two diseases are not completely understood. Both diseases are considered to be inflammatory conditions and, therefore, immune mediators likely play a role in the shared susceptibility between two diseases. Adipokines have numerous immunological properties and their concentrations are altered in diabetes. Myeloid cells are key leukocytes in responses to periodontal pathogens such as Porphyromonas gingivalis. Therefore, the present study aimed to investigate the role of leptin and adiponectin in myeloid cell immune responses and in T2DM patients as potential mediators in an immunological link between diabetes and periodontal disease. Leptin increased both E. coli and P. ginivalis LPS-induced TNF-α expression in monocytes. Although leptin had no effect on TLR4 expression, leptin did upregulate TLR2 and enhanced monocyte differentiation. Together, these results indicate the potential of leptin to alter monocyte immune responses to periodontal pathogens. Male but not female T2DM patients with gingivitis of chronic periodontitis had increased serum leptin concentrates in comparison to matched, non-diabetic controls. Serum adiponectin concentrations were not effected by periodontal status. In contrast, gingival crevicular fluid (GCF) adiponectin concentrations were higher in periodontal disease in both T2DM patients and non-diabetic controls. GCF adiponectin concentrations were a predictor of periodontal status independent of BMI or gender. Serum adipokine concentrations were not affected by periodontal treatment. A decrease on GCF adiponectin concentrations was observed in T2DM patients and non-diabetic controls after periodontal treatment. In conclusion, findings of the present study demonstrate a role for leptin in monocyte differentiation and immune responses towards periodontal pathogens. In addition, analyses of clinical samples revealed that leptin and adiponectin are a potential link between diabetes and periodontal disease. In particular, GCF adiponectin concentrations may represent a diagnostic marker for diabetes and periodontal disease.
74

3D geometric morphometric analysis of tooth shape in hypodontia

Al Shahrani, Ibrahim Sulaiman A. January 2012 (has links)
Assessment of tooth morphology is essential in the diagnosis and management of hypodontia patients. Several techniques have been used to quantify tooth shape in hypodontia patients and these have revealed smaller tooth dimensions and anomalous tooth shapes in these patients when compared with controls. However, previous studies have mainly used 2D images and have thus provided limited information. The present study adopted a novel three-dimensional geometric morphometric technique to quantify the crown morphology and sizes of teeth of hypodontia patients and compare them with those of control patients. Allometric variations were also investigated in order to determine whether there was any association between the size and shape of teeth. Landmarks were recorded on each clinical crown of all the permanent teeth, apart from third molars, of 3D scanned study models of hypodontia and control subjects. The study sample comprised 120 hypodontia patients (40 patients with mild, 40 with moderate and 40 with severe hypodontia) and 40 age- and sex-matched controls. Procrustes superimposition was utilized to scale and superimpose the landmark coordinate data and were then subjected to principal component analysis (PCA). Subsequently, shape differences were tested statistically using multivariate statistics. Size variation was for the most part found to be significant, especially when the control subjects were compared to the hypodontia groups. The anterior teeth were more affected than the posterior. Generally speaking, the size differences became greater as the severity of the hypodontia increased. The pattern was virtually the same for both sexes. With regard to shape, most teeth were affected by the hypodontia, although the pattern was less clear. When allometry was taken into account, the pattern of size/shape relationship was found to be significant for most teeth, particularly in the anterior region, and shape differences were still significant after controlling, when possible, for allometry. It was found that the degree of variation in tooth shape was associated with the degree of severity of the hypodontia. The findings of the study therefore indicate that quantitative measurement of the tooth shape in hypodontia patients may enhance the multidisciplinary management of those patients.
75

Priority setting in dental health care

Holmes, Richard David January 2012 (has links)
Health care resources are often insufficient to meet the demands placed upon them. Managing scarcity and assessing the merits of competing priorities are therefore key responsibilities for health care decision-makers. In April 2006, the new General Dental services (nGDS) contract introduced local commissioning to NHS dentistry for the first time. Primary Care Trusts (PCTs) were charged with managing devolved and finite resources, but they have since drawn criticism as a consequence of variable quality commissioning. Economics may offer some solutions to assist NHS commissioners. Programme Budgeting and Marginal Analysis (PBMA) is a pragmatic economics-based approach which may inform and assist decision-makers to prioritise scarce resources. The research was divided into three phases: a national qualitative survey of NHS decision-makers' roles in managing scarce dental resources; a PCT -based qualitative case-study involving patients, dentists and PCT staff; and a PBMA- based dental priority setting exercise. Phases 1, 2 and 3 collectively used semi- structured interviews, focus groups, an action research approach and mixed methods. The research highlighted that dental decision-makers were constrained in their ability to commission dental services as a consequence of restrictions imposed by the national dental contract. Local priority setting and resource allocation generally lacked transparency and decision-makers typically failed to include patients and clinicians in these processes. With respect to health economics, stakeholders found the pictorial representation of the cost-value ratio (CVR) a useful starting point for further deliberation, but the full application of a traditional PBMA exercise was hindered locally by organisational change and severe PCT staffing pressures. The concerns identified by stakeholders are timely considering the Government's proposals to abolish PCTs and commission NHS dental services through the NHS Commissioning Board alongside a new national dental contract in 2014.
76

The impact of development defects of enamel on young people

Marshman, Zoe January 2007 (has links)
Background: in order to ascertain whether Developmental Defects of Enamel (DDE) constitute a public health problem it is necessary to consider whether the condition impacts on the lives of affected individuals. Aim: to describe the impact of DDE on individual young people. Objectives: 1) Describe the extent to which contemporary dental research on DDE has included the perspective of children and young people. 2) Describe the impact of DDE on the oral health-related quality of life (OHRQoL) of young people. 3) Explore, in detail, the impact of DDE on young people. Methods: a systematic review of the literature, a cross sectional study and a qualitative interview study were conducted. Results: Little research about DDE has previously attempted to capture the subjective experience of those with the condition. The impact of DDE, as measured with a child specific OHRQoL measure, was generally of low frequency and was equivalent to that of young people with relative oral health. In qualitative interviews the impact of DDE varied markedly between young people. DDE impacted on individuals' whose sense of self was defined by appearance and who depended on perceived approval from others about their appearance. No links between gender, age, severity of DDE and impact were apparent. Discussion: The impact of DDE was generally of low frequency with marked variation in impact between individuals. This research is the first to discover that some of this variation can be accounted for by young people's sense of self. This concept has not been identified in relation to the impact of visibly different conditions before. More research is needed to further investigate the impact of DDE.
77

Dental ceramics: microstructure and fracture behaviour

Ereifej, Nadia January 2008 (has links)
No description available.
78

Evidence-based guidelines in dentistry

Glenny, Anne-Marie January 2005 (has links)
Background: Clinical guidelines have an important role to play in helping to close the gap between research evidence and clinical practice. In order to fulfill this role, guidelines need to be valid, relevant and comprehensive. Despite advances in chemotherapy and radiotherapy, cancer treatment still remains associated with clinically important oral complications that can impact severely on a patient's quality of life. No clear guidelines exist outlining the optimal oral care strategy for children, teenagers and young adults treated for cancer. Aims: (i) To assess the quality of current clinical guidelines for those working within dentistry; (ii) To develop evidence-based guidelines on mouth care for children, teenagers and young adults being treated for cancer; (iii) To compare the quality of published guidelines and their recommendations in light of supporting research evidence. Methods: (i) Dental guidelines, published in English between 1997-2004, were appraised using the Appraisal of Guidelines Research and Evaluation (AGREE) instrument; (ii) A telephone survey of UK cancer centres was undertaken to establish current practice with regard to mouth care for children treated for cancer. National, evidence-based guidelines were developed following, where appropriate, the established methodology of the Scottish Intercollegiate Guidelines Network (SIGN); (iii) A qualitative assessment of previously published guidelines on mouth care for cancer patients was undertaken. Results: (i) The AGREE instrument identified few examples of good quality dental guidelines; (ii) There is diversity in the mouth care provided to children being treated for cancer in the UK, particularly with regard to the use of routine, preventative oral care therapies. The guideline development process required a combination of an evaluation of research evidence and a formal opinion gathering process. A variety of interventions have been used for the management of oral mucositis, candidiasis, xerostomia and herpes simplex virus; few are supported by the research evidence; (iii) Variation exists in the methods used to produce previously published guidelines on mouth care for cancer patients. Recommendations vary irrespective of the supporting evidence-base. Conclusion: Guidelines need to be assessed for quality before being applied in practice. The guideline development process needs to be transparent, with clear links between recommendations and supporting evidence. There is currently variation in the mouth care provided to children, teenagers and young adults being treated for cancer in the UK. National, evidence-based guidelines may help to reduce this variation. Further research is required into the most effective methods of dissemination and implementation, exploring the role of psychological models of behavioural change.
79

The biomaterials and biomechanics of dental restorations : property measurement and simulation

Li, J. January 2008 (has links)
The aim of this study was to improve the accuracy of the predicted shrinkage stress in dental restorations by exploring the interrelationships between the shrinkage stress, the material parameters, the polymerisation shrinkage and the filler content of the composite, through a series of numerical simulation and experimental measurements. Firstly, as a preliminary study, the mathematical solution of a 2D axisymmetric model of a Class-I dental restoration during resin polymerization was used, to evaluate the effect of each of the above factors on shrinkage stress. The subsequent sensitivity analysis based on the analytical solution showed that shrinkage is the most important factor in the development of shrinkage stresses, followed by Young's modulus and viscosity. Secondly, experiments were conducted on an experimental composite to express its micro hardness, Young's modulus and viscosity as functions of the volumetric shrinkage. Shrinkage was measured with the digital image correlation method. Thirdly, the effects of the volumetric filler fraction and filler morphology on the material properties of dental composites were considered using finite element micro-structural models. Fourthly, the shrinkage stress produced by the experimental composite in the Bioman shrinkage-stress instrument was simulated using the finite element method. Good agreement between the simulation and experiment indicated that the material properties determined using the above methodology are likely to be representative. Finally, 3D finite element models were employed to calculate the shrinkage stresses in a restored premolar, considering different filler contents in the composite, different filling methods and different cavity shapes. Results showed that the filler content is not the most crucial factor in the development of shrinkage stress in dental restorations, and the incremental filling method can significantly reduce the overall shrinkage stress in dental restoration.
80

Clinical aspects and related factors influencing osseointegration and function of dental implants

Alissa, Rami January 2010 (has links)
No description available.

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