Bacterial and fungal biofilms are an increasing clinical challenge, from non-healing wounds to chronic lung infections in cystic fibrosis (CF) patients. Escalating antimicrobial resistance has led to a need for alternative treatments. OligoG (a low MW alginate oligosaccharide), can disrupt multi-drug resistant bacterial biofilms and decrease antibiotic resistance. This study characterised the interaction between OligoG and the most prevalent CF pathogen, Pseudomonas aeruginosa, using nanoscale characterisation, imaging and fluorescent conjugation. Further investigation into the effect of OligoG on CF sputum was carried out using Fourier transform infrared spectroscopy (FTIR) and rheology. The work was extended to observe changes in fungal pathogens treated with OligoG. Electrophoretic light scattering (ELS) and dynamic light scattering revealed that the surface charge of P. aeruginosa became more negative when treated with OligoG (P<0.001) with an increase in sizing. These interactions were not disrupted by hydrodynamic shear (P<0.0001). Biofilm inhibition and disruption of a mucoid P. aeruginosa strain, treated with OligoG, was demonstrated using confocal laser scanning microscopy (P<0.05). Fluorescent conjugation to OligoG revealed its distribution throughout the biofilm. In vitro scanning electron microscopy (SEM), atomic force microscopy (AFM) and ELS of mucin showed disruption in aggregation when treated with OligoG (P<0.005), with the surface charge becoming more negative (P<0.0001). Ex vivo treatment of CF sputum with OligoG analysed using FTIR and rheology, demonstrated possible interaction with the sulfate moiety of mucin and a reduction in the viscous and elastic response (0.16 Hz; P<0.0001). AFM and SEM analysis of candidal biofilms treated with OligoG demonstrated a dose response in reducing biofilm formation, with a decrease in hyphal formation. An in vitro epithelial model demonstrated these changes at <2% OligoG. These studies provide insight into the role of OligoG as a treatment for CF patients. Furthermore, promising results have shown that OligoG may lower candidal pathogenicity.

Spinal cord regeneration following injury represents a major clinical challenge. Over recent years, stem cells have demonstrated promise for promoting spinal repair in the lab and in early stage clinical trials through functional replacement of neuronal and glial cells and through secondary trophic mechanisms to promote endogenous regeneration. Research has primarily focused on the use of embryonic tissue-derived stem cells of potentially limited therapeutic application due to related ethical concerns. The dental pulp harbours a source of easily accessible progenitor cells that have demonstrated early promise in improving functional outcome of experimental models of spinal cord injury via growth factor release. This thesis explores the potential of dental pulp progenitor cells (DPPCs) to promote spinal repair through direct cellular replacement. Progenitor cells isolated from murine incisors were found to express early stage neural and glial markers. Specific protocols were developed demonstrating the ability of DPPCs to differentiate in vitro into neuronal-like and oligodendrocyte-like cells with appropriate morphology and expression of mature markers. Electrophysiological testing revealed that DPPC-derived neuronal-like cells were of an immature non-functional phenotype. Undifferentiated DPPCs injected into an ex vivo spinal cord slice model showed signs of proliferation, migration and spontaneous differentiation within spinal tissue. DPPCs pre-differentiated into oligodendrocyte-like cells failed to survive transplantation but neuronally pre-differentiated cells survived, showing signs of integration into endogenous neuronal pathways. In a small scale pilot study, neuronally pre-differentiated DPPCs were transplanted into a clinically relevant in vivo model of spinal cord injury. DPPCs maintained expression of neuronal markers four weeks after grafting into the injured spinal cord. Axonal projections towards grafted cells and synaptic protein expression suggested possible integration into neuronal pathways, albeit without an associated statistical functional improvement. The results presented in this thesis provide a strong case for the potential of DPPCs to facilitate functional recovery through direct cell replacement mechanisms.

Type 1 diabetes mellitus (T1DM) is a complex metabolic condition that results in hyperglycemia due to insulin deficiency (Daneman, 2006). Diabetes has a range of effects on almost every system in the body including the kidneys, the eyes, the cardiovascular system, the genito-urinary system, the gastro-intestinal system and the nervous system (Daneman, 2006). The effects of this ondition are widespread and have a significant impact both on life expectancy and the quality of life of individuals suffering from diabetes (Scottish Diabetes Survey Monitoring Group, 2011). The impact of diabetes on oral health has been investigated over many decades, however, the conclusions have been varied and study design has not always been adequate (Mealey et al., 2006; Khader et al., 2006; Chávarray et al., 2009). Research presented in this thesis is largely the result of a cross-sectional clinical study examining the oral cavities of non-smoking T1DM patients, funded by the Chief Scientist Office of the Scottish Government. The clinical part of the study took place between January 2006 and May 2009 in Glasgow Dental Hospital. Chapter one provides an introduction and narrative review on the subject of T1DM, periodontal disease, and the various other reported oral manifestations of diabetes mellitus. The methods for measuring general and oral health related quality of life outcomes are also discussed. Chapter one reveals some of the inadequacies of studies nvestigating the link between T1DM and oral disease to date and ontextualises the studies presented in this thesis. Chapter two presents the main periodontal findings of a large cross-sectional study. 112 non-diabetic subjects and 203 subjects with type 1 diabetes were examined. 203 diabetic patients were divided into well controlled and poorly controlled groups based on their average blood sugar levels over the previous two years. 169 were poorly controlled. (PCD). Those with T1DM, (especially those with poor glycaemic control) had a greater extent and severity of periodontitis than those without diabetes. There was also some evidence that never smoking T1DM patients were more likely to have periodontal disease than non-diabetic subjects. The odds ratio (OR) was 1.43 [0.74 to 2.75] (p = 0.29) for all T1DM patients and 1.58 [0.75 to 3.33] (p = 0.23) for PCD. This difference remained even after the multivariable analysis took into account age, gender and lifestyle including: body mass index of the subject; whether they had smoked in the past; whether they attended a dentist; their level of education and how deprived the area they lived in was. Chapter three presents an analysis of the impact of age, HbA1c, and duration on the expression of periodontal disease in T1DM subjects. Cross-tabulations and multivariable logistic regression analysis was performed on the periodontal data from T1DM subjects and non-diabetic subjects in order to determine the relationship between age, HbA1c and duration, and periodontitis. Diabetic subjects developed periodontitis at a younger age than non-diabetes subjects. This will represent a significant impact on life time dental service provision for subjects affected at a young age. The relationship between HbA1c and severe periodontitis is not a simple one. It is possible that unknown factors confound the relationship between glycaemic control and periodontitis. There was no relationship between duration of diabetes and periodontitis when age was controlled for. Chapter four presents the results of a small study investigating biomarkers of bone turnover in patients with and without T1DM and in patients with and without periodontitis. Patients with T1DM had higher levels of osteoprotegerin an osteoprotective molecule that normally leads to a reduced propensity for bone loss. T1DM patients were also shown to have reduced levels of biomarkers of bone formation (osteocalcin). It is possible that a reduced capacity for bone repair and regeneration may account for the increase levels of periodontitis seen in T1DM. Further prospective studies would be required to confirm this hypothesis. Chapter five investigated the level of caries and oral mucosal abnormalities in T1DM. There was little difference in caries indicators or in oral mucosal lesions between the groups. There was no difference in the bacterial microflora and in the level of resistance to antibiotics found in this cohort. T1DM patients, however, did have an increase in the symptoms of dry mouth, an increased density of candida colonisation and reduced salivary flow rates.Chapter six reports the data derived from the oral health questionnaire, including the Oral Health Impact Profile -14 (OHIP-14) and the Audit of Diabetes Dependent Quality of Life (ADDQOL©). Patients with T1DM, despite having increased levels of periodontal disease, reduced salivary flow rates and increased symptoms of xerostomia did not have higher OHIP scores by any measure. The reasons for this apparently negligible impact of oral disease or oral health related quality of life are discussed. The OHIP-14 was shown to have construct validity in this population although the correlations were relatively weak and the differences were small. It is possible that patients with T1DM do not consider the impact of their oral health to be a significant problem in light of their other on-going medical issues. This finding requires further in-depth investigation of the psychology behind this apparent reduced impact. This is the first study of its kind to examine the oral and dental health of non-smoking type 1 diabetic patients. The conclusions from the clinical data support the view that patients with T1DM should be targeted with oral and dental health advice. Encouragingly the prevalence of periodontitis was lower in well controlled diabetic subjects suggesting that the effect of T1DM on the oral cavity can be ameliorated by good glycaemic control even though logistic regression analysis did not show a linear relationship. It is important that health rofessionals work together in order to prevent and manage the oral complications of T1DM in the same way that there are preventive and screening programmes for other diabetic complications. The pathogenesis behind the increased prevalence and severity of periodontal disease in T1DM requires further study.

There has been an ongoing debate regarding appropriate strategies for the management of carious primary teeth. Studies appear to provide evidence that both selective, symptom-based interventions and traditional restorative strategies are advantageous. However, the analysis and quantification of childhood caries may be affected by clustering of data, and the concurrent risk of exfoliation of primary teeth. Multilevel generalised linear models for the occurrence of primary caries were derived utilising data from a cohort study of 2,654 children aged 4-5 years at baseline undertaken 1999-2003. These models, which assumed underlying hierarchies with clustering at child, tooth and surface levels, identified higher rates of caries occurrence in primary molar teeth to be associated with boys, poor socio-economic background, lack of water fluoridation, 2nd mandibular molars and occlusal surfaces. Significant risk factors identified were carried forward for inclusion in parametric competing risks multivariate multilevel survival models, utilising cohort study data augmented with Dental Practice Board treatment data. Analysis of sound teeth and surfaces found the concurrent risk of exfoliation did not alter inferences of parameter significance, but restricted the extent of caries occurrence and reduced distinction in survival experience between different types of teeth and surfaces in children from different demographic backgrounds. Further competing risks survival models were derived to analyse the same teeth and surfaces in the untreated carious and filled states, to assess the effect of restorative treatment on subsequent exfoliation and extraction. Survival rates extrapolated to 14 years without further treatment for filled molar teeth were approximately double those of untreated teeth. Time of caries occurrence and treatment also affected survival, with later occurrence or treatment of caries associated with higher survival rates. However, early filling of carious teeth resulted in the greatest reductions in the expected time that decay is present in the mouth.

Aim: To evaluate the longitudinal relationship of anterior tooth alignment and intra-oral plaque accumulation during orthodontic fixed appliance treatment, using novel intra-oral imaging techniques. Design: Prospective observational cohort study. Setting: Countess of Chester Hospital Subjects: 13 adolescent patients (9 females, 4 males) recruited prior to commencing fixed appliance therapy. The mean age of patients recruited was 13.4 years with an age range of 11.9 – 17 years. Methods: Clinical data were collected for each participant at consecutive appointments until the anterior teeth were aligned with the minimum follow-up being 6 months. Data included an assessment of plaque accumulation using a novel hand-held device (ToothcareTM) and upper and lower labial segment crowding was evaluated using sectional plaster models to determine the Little’s Irregularity Index [1975]. Repeat measures were used to assess reliability of the plaque scoring method and measurement of the Little’s Index via dial callipers and a reflex metrograph. The accuracy of hand scoring Little’s Index was also compared to the reflex metrograph measurements. Dahlberg’s method error formula was used to determine the accuracy of Little’s Index scores whilst Cohen’s Kappa statistic determined the degree of agreement in repeat plaque measurements. Uni-variate non-parametric statistics were used to assess any differences between test re-test measurements and Spearman’s Correlation Coefficient was used to determine associations between plaque and crowding over time. The multi-variate Kruskal-Wallis test was used to examine the trend of plaque and crowding over time. Results: Spearman’s Correlation Coefficient showed an inverse relationship between plaque and crowding over the course of the study (r = -0.375) although this association was very weak. The inverse relationship was stronger for the baseline data (prior to bonding of the fixed appliances) r = -0.602, which was statistically significant at the five percent level. There was no consistent trend amongst patients of plaque accumulation over time (p=0.741) although the degree of labial segment irregularity did consistently improve over the first three visits (p=0.038). Hand scoring with dial callipers showed acceptable accuracy with a method error of 0.17mm, although the reflex metrograph did not show the same consistency (method error = 0.22mm) and tended to over score the irregularity when compared to the hand scoring method (p=0.000). Reproducibility of the plaque scoring method was acceptable when using the ToothcareTM light at the chair side (un-weighted kappa statistic = 0.92) and when compared to an image from the digital camera based on the same technology, QLF-D BiluminatorTM (un-weighted kappa statistic = 0.76). Conclusions: The plaque scoring index based on a novel hand-held device (ToothcareTM) shows acceptable reliability and reproducibility. Measuring Little’s Irregularity Index [1975] by hand may be preferable to using a similar index on a reflex metrograph due to the increased error in the vertical dimension. Plaque accumulation does not appear to show a consistent trend over time and is very variable in nature. In this cohort there was a very weak and inverse relationship demonstrated between labial segment crowding and plaque quantity.

Background: The QUOROM and PRISMA guidelines were created in an attempt to improve the standard of reporting systematic reviews. At present there are no studies in the dental literature that have assessed the compliance of papers with these two sets of guidelines. Aims: To determine whether the reports of systematic reviews in four dental specialities comply with the QUOROM and PRISMA statements, whether there has been an improvement in standard over time and whether Cochrane reviews differ from other reviews. Design: Retrospective observational study Method: A search of the Cochrane library identified 181 systematic reviews and meta-analyses for inclusion across four dental specialities (orthodontics, periodontics, preventive dentistry and endodontics). Each review was scored using a 63-item checklist developed from the QUOROM guidelines and a 63-item checklist developed from the PRISMA guidelines. Results: The mean QUOROM score for the whole sample was 70.86% (SD 11.36%, 95% CI 69.20%, 70.86%) and the mean PRISMA score for the whole sample was 74.07% (SD 10.48%, 95% CI 72.53%, 75.61%). The mean PRISMA score for Cochrane reviews was 85.19% (SD 5.03%, 95% CI 83.79%, 86.59%) and the mean PRISMA score for non-Cochrane reviews was 69.59% (SD 8.60%, 95% CI 68.09%, 71.09%). This difference was statistically significant (mean difference 15.50% (95% CI 13.58%, 17.62%; p<0.00001). The mean PRISMA score for orthodontic papers was 75.07% (SD 10.36%, 95% CI 72.32%, 77.82%), for periodontic papers it was 74.91% (SD 7.96%, 95% CI 72.80%, 77.03%), for preventive dentistry papers the means score was 71.50% (SD 13.73%, 95% CI 67.22%, 75.78%) and for endodontic papers the mean score was 74.20% (SD 9.37%, 95% CI 70.33%, 78.07%). The differences between these scores was not statistically significant (p = 0.851). There was a weak negative linear relationship between the age of a Cochrane review and its PRISMA score, indicating a small improvement in compliance with the PRISMA guidelines over time. This was statistically significant (p = 0.019). There was also a weak negative linear relationship between the age of a non-Cochrane review and its PRISMA score but this was not statistically significant (p=0.422). The age of a paper, the speciality it belonged to and the type of review (Cochrane versus non-Cochrane) accounted for 46.5% of the variability in the final PRISMA score. Conclusions: The compliance of systematic reviews and meta-analyses with the QUOROM and the PRISMA guidelines was highly variable. There were significant differences between the PRISMA scores of non-Cochrane reviews and Cochrane reviews with the latter scoring more highly. There was also a slight increase in the compliance of Cochrane reviews over time, which was statistically significant. Although the speciality of orthodontics had the highest mean PRISMA score, there were no significant differences between the four specialities.

Management of fungal biofilms represents a significant challenge to oral healthcare. As a preventive approach, minimising adhesion between intra-oral devices and microorganisms would be an important step forward. Denture stomatitis (DS) is a multifactorial denture-associated inflammation of the oral mucosa where candidal biofilms are one of the contributing factors. Therefore, understanding candidal biofilms on dentures and finding novel strategies to control these biofilms are of significance. Interference with the adhesion step of biofilm formation is hypothetically effective strategy to control biofilms. To understand the relationship between denture candidal load, denture material type and C. albicans biofilm forming heterogeneity in DS, quantitative polymerase chain reaction (qPCR) molecular method and crystal violet (CV) assay were used. This study investigated two novel strategies to control C. albicans biofilms through interfering with adhesion: natural polyphenol curcumin (CUR) and modifying the topography of the denture material surface. Based on the optimised effective CUR concentrations, CUR adsorption to PMMA denture material was spectrophotometrically analysed. Based on these data, the effect of adsorbed CUR to PMMA and CUR pre-exposure on adhesion of C. albicans were assessed. The effect of CUR on Candida-Candida adhesion was investigated and the expression profile of selected adhesion and aggregation-associated genes was assessed using qPCR method. Micro/nano-fabricated polycarbonate and PMMA materials were replicated using injection and compression moulding techniques, respectively and were characterised using scanning electron microscopy (SEM). Adhesion of C. albicans on the micro and nano-scaled patterns was assessed using microscopic and qPCR molecular methods, respectively. The physical characteristics of the materials were assessed using theta tensiometer and a white light profiler. The data demonstrated that although C. albicans was detected in greater quantities in diseased individuals, it was not associated with increased biofilm biomass. Denture substrata were shown to influence biofilm biomass, with poly(methyl methacrylate) providing the most suitable environment for C. albicans to reside. Subsequent studies showed that CUR concentrations of 50 μg/ml could prevent adhesion to PMMA. This effect was enhanced by the CUR pre-treatment of yeast cells (>90% inhibition, p < 0.001). Investigation of the biological impact of CUR showed that it preferentially affected immature morphological forms (yeast and germlings), and actively promoted aggregation of the cells. Transcriptional analyses showed that CUR temporally modulated adhesion and aggregation associated genes. Finally, PMMA denture material was replicated to show nano features. These topographies influenced adhesion of C. albicans, depending on the candidal morphological form and the shape. Nano-pit spatial arrangements variably affect the adhesion of C. albicans, where SQ arrangement demonstrated a significant anti-adhesive capacity. Differential adhesin expression was observed on these surfaces, which were affected by the wettability and roughness of surfaces tested. In summary, C. albicans is an important determinant of denture disease, so preventing its adhesion and biofilm formation were worthwhile objectives. This thesis has shown that CUR molecules and SQ nano-pit topographies reduced C. albicans adhesion, demonstrating that chemical and physical inhibition strategies are useful. The data presented in this thesis showed the high potential of the novel strategies to be used against C. albicans biofilms, and encourages the further investigation of these approaches against polymicrobial denture biofilms.

This thesis investigated different quantitative methods for dental plaque detection using digital imaging. Firstly, based on a commercially available two-tone disclosing, the concentration of the dyes in the blue disclosing solution was calculated. This blue dye was used to disclose dental plaque accumulated on natural teeth and complete upper dentures (on two different backgrounds). Digital images were acquired under visible light, in the n-IR spectrum and with a narrow band-pass interference (NIB) filter tuned to the absorption spectrum of the blue dye. The results showed that disclosing dyes and disclosed dental plaque are transparent in the n-IR spectrum whilst the NIB filter maximised the contrast of dental plaque in the images when using the blue stain. A number of computerised segmentation methods were applied to these images showed automation of dental plaque detection to identify reliable methods to quantify plaque coverage. Although minor human intervention was still required in the segmentation process, the continuous development of new software promises that full automation in plaque quantification is almost a reality. Finally, analysis of the inter- and intra-examiner reliability of the commonly used Quigley and Hein index showed moderate reliability, highlighting the need for automated, quantitative and more reproducible methodology.

The aim of this study was to explore the potential and challenges for e-learning in dental education using a case-study approach. The University of Birmingham, School of dentistry, e-learning platform “e-course”, was assessed at four stages. The attitudes of third year dental students towards an online orthodontic e-course were assessed to explore students’ learning needs using a five Likert-scale questionnaire. The different tools and components on the e-course were explored to assess its technical and instructional efficiency using descriptive analysis. The Prosthetic discussion archive was analysed for its efficiency to support a higher-level of teaching and learning using content analysis. Dental students and academic teachers were interviewed using one-to-one interviews and focus groups. Their attitudes towards e-learning in dentistry were analysed for emerging themes in three main categories; technological, pedagogical, and curriculum design. E-learning has shown great potential in supporting change to dental education. There are differences between students and teachers. Students are enthusiastic in its use, whilst teachers have many concerns on its implementation related to work load and use of information. E-learning has a great potential in supporting curriculum reform in dental education, but is not fully utilised. Institutional strategies and support together with strong leaderships is needed when implementing e-learning into a dental school.

This research investigates the interplay between strategy, innovation, oral health inequalities, and the Primary Care Organisation (PCO). There has been little previous consideration of the interplay between these four factors, which this research addresses through a mixed-methods approach combining interviews, secondary-data analysis, and an investigation into the availability of oral health strategies. Analysis was supported by dialectic and functionalist approaches and suggested that structural and process difficulties affected the ability of PCOs to address inequalities in oral health through strategy and innovation. The role of PCOs and consultants in dental public health in relation to strategy and innovation was characterized by contradictions and inconsistencies, some of which appeared to be dysfunctional. The findings raise a number of considerations regarding the role PCOs adopted with regard to oral health inequalities. In particular, this thesis demonstrates that local and macro-level structures and processes may be inadequate to ensure reductions in oral health inequality through strategy and innovation. Integration of strategy and innovation in this thesis leads to a suggested innovation-strategy complex.