The current clinical choice for bone regeneration is autologous bone grafts from the iliac crest. The associated drawbacks, however, in terms of morbidity and low cell number following tissue harvest, have led to search for alternative stromal cell sources in conjunction with native tissue matrix components. For mineralised tissue engineering, alternative to mesenchymal bone marrow stromal cells (BMSCs), mesenchymal dental pulp stromal cells (DPSCs) have been proposed due to high colony formation and differentiation potential. Understanding which stromal population is exemplar for rapid and effective regeneration is paramount, and central to efficient bone regeneration is providing the optimal microenvironment to the characterised stem cells. This thesis compared clonal BMSCs that formed few and large colonies, with DPSCs that formed many small colonies. Comparison of clonal differentiation along adipogenesis, chondrogenesis, with particular attention on their capacity for osteogenic formation, showed BMSCs were multipotent, while DPSCs only displayed uni- and bi- potency (osteogenic inclusive). Neither VCAM1 nor MCAM mesenchymal marker expression related to differentiation capacity. Stromal clones exposed to whole-protein tissue matrix extracts from bone (BME) and tooth (TME), found in vitro mineralisation by BMSCs and DPSCs with TME, but mineralisation by DPSCs only with BME. BMSC and DPSC clones were also assessed on bone- and tooth- slabs to replicate in vivo injury of fracture and caries, respectively. BMSCs and DPSCs displayed proliferation and differentiation on tissue-slabs, but BMSCs did not attach to tooth-slab, which was probable of tissue differences in supportive extracellular proteins. In summary, results indicated BMSCs are more primitive stromal cells closely related to the mother stem cell, while DPSCs are more lineage committed and are suggestive of transit-amplifying cells; indicative of their in vivo roles, that is, bone is remodeled constantly and tooth responds to injury only. While much research is still required, DPSCs and their matrix-proteins potentially offer an easily accessible and viable alternative for craniofacial bone reconstruction.

A significant number of young children in the United Kingdom experience dental caries, often resulting in a diminished quality of life. Brushing children’s teeth twice a day with fluoride toothpaste significantly reduces their risk of caries, but not all parents adhere to these guidelines. Previous behaviour change interventions in oral health have been largely unsuccessful and criticised for a narrow focus on education with no wider theoretical underpinnings. However, little is known about the factors that influence parents’ decisions about when and how often to brush their child’s teeth at home. The aim of the current project was to understand the wider social, environmental and cognitive factors that influence parents’ decisions about brushing children’s teeth, to inform future advice and interventions. Three studies were conducted, focused on parents of children aged between 3-6 years old, resident in deprived communities in Wales. In-depth interviews (n=15) suggested that parents only took brushing guidelines seriously if they believed other parents did so, that toothbrushing patterns were influenced by the home environment and day-to-day routines, and that parents often saw toothbrushing as having largely short-term benefits. These themes informed the development of a questionnaire survey (n=297), which showed that parents’ perceptions of the norm for brushing were significantly associated with how often they brushed their own child’s teeth. Parents tended to brush their child’s teeth more often when brushing was automatic or ‘habitual’ and saw different benefits in brushing a child’s teeth in the morning and evening. Finally, an experimental study (n=121) showed that parents’ judgements about what constitutes a healthy number of times to brush a child’s teeth were relative rather than absolute, and predicted by Range-Frequency Theory. The findings have implications for re-considering oral health advice offered to parents, and suggest novel theoretical frameworks for developing future behaviour change interventions.

This thesis is an evaluation of interprofessional education (IPE) in Leamington Spa Orthodontics (LSO), a primary care outreach training centre. It is relevant, as there are no IPE studies in dentistry and timely, offering a model of integrated education and patient care. As a longitudinal study, where IPE is the organisational philosophy, it is significant in informing theorisation of IPE. The methodology is realist evaluation, which aims to describe and understand the educational environment and identify how stakeholders perceive their experiences. The study group spans the full spectrum of stakeholders in LSO education, selected by purposive sampling. Data collection is by semi-structured interviews and focus groups. Thematic analysis allows in-depth data immersion, developing theory iteratively until saturation is achieved. Identified theories are tested and refined by stakeholders, thus providing respondent validation. Findings show IPE in LSO to be successful for the orthodontic team. A core philosophy and attitude are the initiating contexts, which, with time, allow development of an appropriate skill-mix, organization and setting to facilitate learning. Empowerment leads to aspects of unlearning, reflection, formal and informal learning, combining with situated learning to deliver interprofessional learning. Outcomes include individual and team development, enhanced teamwork, communication and depth of learning. IPE evolves through situated learning in a conducive community of practice, where individuals develop their own identities, or learning trajectories, unrestricted by professional protectionism. To be sustainable, IPE must become organisationally contextual, which is dependent upon emergence of new leaders and, requires buy-in from and continuing motivation of the majority of stakeholders. This thesis identifies contexts required for IPE, mechanisms which generate defined outcomes, and suggests that a customized primary care setting is ideally suited for its’ development. IPE has struggled to transform healthcare professional education. An institutional teaching model, with IPE as the core philosophy, may achieve this goal. This thesis therefore suggests that IPE should be an overarching educational theory in its own right, within which other social science and education theories combine, to maximize integrated learning and patient care.

Aim: The primary aim of this study was to develop, calibrate and assess a novel methodology that employs 3D scanning technology in quantifying the progression of tooth wear and then assess the applicability and validity of this methodology in-vivo through clinical monitoring of the progression of tooth wear in patients over a period of 12 months. Methods and materials: A Stainless Steel Model (SSM) was fabricated consisting of seven stainless-steel ball-bearings embedded in a horseshoe-shaped base. The dimensions of the SSM were ascertained using a Coordinate Measuring Machine (CMM). The CMM calibrated SSM was used to identify the accuracy and precision of a contact stylus profilometer scanner and a non-contact class-II laser arm-scanner. The next stage involved using the SSM to identify the initial dimensional accuracy of Type IV dental stone casts poured from impressions of the SSM, using 3 types of impression materials: alginates (Alg), polyethers (PE) and polyvinylsiloxanes (PVS), and the dimensional stability of the dental stone over a period of one-month. Thereafter, the overall 3D scanning system performance was calculated. A clinical study involving tooth wear patients, recruited through 3 Restorative Dentistry Consultants’ New Patient clinics, was also carried-out. At initial visit and after 1 year, PE impressions were taken of participants’ dentition and poured. At 1 month post-pouring, the casts were 3D-scanned. The resultant scans of initial visit casts and after 1 year casts were 3D analysed, compared and differences detected. Results: The contact scanner demonstrated greater accuracy and precision compared to the non-contact scanner. Alg-fabricated casts demonstrated the largest discrepancy, producing undersized casts. PVS was the most accurate but concurrently demonstrated greater statistical variance compared to PE. The overall 3D scanning system performance, when comparing 2 individual contact scans taken of Type IV stone casts poured from PE impressions then scanned at one-month post-pouring, was 66μm. Clinically, all participants in this study presented with tooth wear greater than 140μm in depth; however, detected tooth wear only affected a limited surface area of anterior teeth. Conclusion: In this pilot study, we were able to formulate a novel descriptive 3D scanning methodology for quantifying tooth wear that accounts for the various factors affecting 3D scanning in-vivo. We have also demonstrated the clinical applicability of the methodology in monitoring the rate of tooth wear progression in patients.

A 3D imaging system (C3D®), based on the principles of stereophotogrammetry, has been developed for use in the assessment of facial changes following orthognathic surgery. Patients’ perception of their facial appearance before and after orthognathic surgery has been evaluated using standardised questionnaires, but few studies have tried to link this perception with the underlying two-dimensional cephalometric data. Comparisons between patients’ subjective opinions and 3D objective assessment of facial morphology have not been performed. Aims: (1) To test the reliability of the 3D imaging system; (2) to determine the effect of orthognathic surgery on the 3D soft-tissue morphology; (3) to assess skeletal changes following orthognathic surgery; (4) to evaluate soft-tissue to hard-tissue displacement ratios; (5) to ascertain the impact of orthognathic surgery on patients’ perception of their facial appearance and their psychosocial characteristics, (6) to explore the dentofacial deformity, sex and age on the psychosocial characteristics; (7) to evaluate the extent of compatibility between the cephalometric and the three-dimensional measurements and (8) to determine if the magnitude of facial soft-tissue changes affects the perception of facial changes at six months following surgery. Results and Conclusions: C3D imaging system was proved to be accurate with high reproducibility. The reproducibility of landmark identification on 3D models was high for 24 out of the 34 anthropometric landmarks (SD£0.5 mm). One volumetric algorithm in the Facial Analysis Tool had an acceptable accuracy for the assessment of volumetric changes following orthognathic surgery (mean error=0.314 cm3). The error of cephalometric method was low and the simulation of mandibular closure proved to be reproducible. 2D soft-tissue measurements were compatible with 3D measurements in terms of distances, but angular measurements showed significant differences (p<0.05).

Periradicular disease (PRD), a localised chronic pathologic inflammatory reaction in response to continuous microbial stimuli from necrotic, infected dental root canals, represents a substantial health care burden. The efficacy of available therapies is sub-optimal and identification of new therapeutic targets is essential. Elucidation of functional interactions between PRD cell populations and tissue matrix and between PRD lesion and cells within the surrounding dentoalveolar bone matrix is prerequisite to this. I hypothesise that the cytokine milieu is central in orchestrating these interactions. I generated a novel human explant tissue culture system to investigate the pathogenesis of PRD. I aimed: (1) to investigate the expression of multiple cytokines, but particularly IL-18, within the human lesion and to elucidate their likely biological contribution towards PRD; (2) to investigate the presence of and functional interactions between inflammatory mediators within human PRD that influence bone homeostasis; and (3) to phenotype the contribution of the PRD fibroblast. Four hundred and fifty patients were recruited after obtaining informed consent. PRD tissue was obtained for investigations, of which 310 specimens were examined in a novel explant culture system. Endogenous cytokine release was readily detected in vitro confirming significant inflammatory activity within chronic PRD and facilitating a detailed analysis for the first time of the complex interactions between cytokine activities in PRD.

The aim of these studies was to research different aspects of the pathogenesis and therapeutic features of recurrent aphthous stomatitis. In support of the involvement of viruses in the aetiology of recurrent aphthous stomatitis, the nested PCR and assays of ELISA and IFA were employed. Results of PCR investigations showed that HHV-6 DNA was present in 29 per cent of aphthous lesions. Using ELISA, specific IgG antibodies against HHV-6 were detected in 96.7 per cent of all serum samples with no significant difference between aphthous patients, oral lichen planus or control subjects. Specific IgM antibodies against HHV-6 were found in a higher prevalence rate in aphthous samples compared with the two other groups: a significant difference of p=0.01 was found between sera of aphthous patients compared with healthy controls. HCMV and VZV DNA were not detected in aphthous samples. Also serological findings did not show any significant increase in the prevalence of specific IgG antibodies against these two viruses. Serum IgM antibodies against HCMV were positive in a small number of samples with no difference between groups and IgM antibody against VZV was not positive in any serum samples. These data fail to show that recurrent aphthous stomatitis can be a manifestation of VZV or HCMV infection or reactivation. However, the possibility of involvement of HHV-6 is raised by the present studies. The possible involvement of Mycobacterium paratuberculosis was examined by the nested PCR investigations. Although mycobacterial DNA was detected only in four biopsy samples of aphthous patients and in none of the oral lichen planus patients or controls, this difference was not significant and more research is necessary to confirm such involvement.

Facial injury is less common in childhood than adulthood. However, it is still a significant cause of morbidity and presentation in hospital emergency departments. The pattern, time trends, and key socio-demographic determinants of facial injuries in Scottish adults admitted to hospital have previously been reported but this is not the case in the paediatric population and the question of whether such injuries are equally distributed across all socio-economic groups has not been answered. In contrast to the epidemiology of facial injuries in the paediatric population, traumatic dental injuries in children and adolescents have become one of the most frequent forms of treatment in dental practice. This suggests that traumatic dental injuries are common in childhood and are a significant cause of morbidity and presentation in hospital emergency departments. The relationship between socio-economic circumstances and the commonest dental disease (dental caries) in Scotland is well established and children resident in the most deprived areas experience more dental disease. However, this relationship with regard to dental injuries in Scotland has not yet been established. In the same way, many answers to questions regarding the sequelae and prognosis of pulpal and endodontic treatment among traumatised teeth remain unclear. Furthermore, numerous studies have been published examining the long term variables that might have an effect on treatment outcomes of avulsed teeth, but none have yet been able to estimate the long term prognosis of avulsed and replanted teeth. Two studies presented in this thesis are largely the result of population based studies investigating the epidemiology of facial and dental injuries in relation to individual demographics. An additional two studies explore the occurrence of paediatric dental trauma and its general treatment outcomes with a specific focus on estimation of the long term prognosis of avulsed and replanted teeth. To establish the epidemiology of paediatric facial injuries in children and adolescents requiring in-patient hospital admission in Scotland and to report the pattern, time trends, and key socio-demographic determinants of paediatric facial injury in Scotland, a descriptive epidemiological population-based study of the incidence of facial injuries in Scotland (2001-2009) was undertaken. Poisson regression models were employed to assess trends. There were 45,388 (4.7 per 1000 population) facial injury cases registered (2001-2009). 60% of injuries were due to non-intentional causes, 15% to motor vehicle incidents, and 9% to assault. 4.5% were alcohol related. The incidence decreased over time from 5.5/1000 in 2001 to 4.0/1000 in 2009. The risk ratio (RR) for males was 1.98 times greater than females (p < 0.001). RR varied significantly between Health Board areas from 0.68 (Dumfries and Galloway) to 1.76 (Grampian) (p < 0.001). There was a significant association between facial injury and deprivation (p<0.001); SIMD 1 (most deprived) had the highest incidence (6.3 per 1000 population; RR =1.89). The findings of this study provide evidence of a continuing increase in the burden of facial injuries in males especially for those who are living in areas of social deprivation, and in certain geographical areas of Scotland. A population-based investigation was undertaken to investigate the pattern and time trends of dental injuries and their socio-demographic determinants among primary one (P1) children in Scotland. Records of Scottish Health Boards' Dental Epidemiological Programme (SHBDEP) and National Dental Inspection Programme (NDIP) for the period 1993 to 2007 were retrieved from the Dental Health Services Research unit - Dundee. Annual incidences of dental injuries were calculated by age, gender, Health Board and DEPCAT (Carstairs deprivation categories). 68,354 P1 children were examined and only 405 (0.6%) had suffered dental injuries (5.9 per 1000 population). There was a significant decrease in incidence over time (1993 figures were three times greater than 2007). Virtually the same incidence rates were recorded for the two genders. However incidence varied significantly between Health Boards (p<0.001); the highest rate being reported in Dumfries (14.2 per 1000 population), which was 11 times greater than Ayrshire (1.3 per 1000 population). There was no significant association between risk of dental injuries and deprivation; in DEPCAT 1 (most affluent) the incidence rate was 6.4 per 1000 population, while in DEPCAT 7 (most deprived) the incidence rate was 5.7 per 1000 population. The findings of this study provide evidence that the incidence of dental injuries had significantly decreased between 1993 and 2007; gender and deprivation level had no effect on the incidence and risk of dental injuries. A retrospective investigation was undertaken to study the sequelae of non-surgical root canal treatment in traumatised anterior permanent teeth of patients referred to a secondary referral centre. The department dental trauma database was used to randomly identify patients who had sustained dental trauma to their permanent anterior teeth between 1994 and 2008 which required pulpal intervention. A data extraction form was designed and completed for each tooth, and then the data was transcribed and processed. The association between treatment outcomes and clinical variables was studied. 100 permanent anterior teeth (72 patients) were studied. Dental trauma was frequent in the age group 9-11yrs (53.9%). Upper central incisors were the most common teeth involved (43.8%). The male: female ratio was 2:1 with an average age at the time of trauma of 10.31 yrs (SD 2.16 yrs). Home and immediate home environs were the commonest location (18%) while falls (34.8%) and injuries during sport/play (34.8%) were the commonest causes. The commonest injuries in this randomly selected group were enamel-dentine fracture with pulp exposure (34.8%) and avulsion (28%). 66.3% received a first treatment intervention less than 24 hours following the injury. Root canal treatment was the most frequent treatment provided, especially for dental avulsion cases (100%). Treatment outcomes were split into three categories: Success (53.4%); Short-term success but long-term failure (35.6%); and Failure (11%). Significantly fewer failures occurred with: developing roots compared to completed roots (P=0.05); a good quality temporary filling (P<0.003); no mobility (P<0.001); and less than one hour extra alveolar dry time (P =0.02). No significance was reached with regard to: condition of root canal (P=0.095); extra alveolar time (EAT) (P=0.191); and type of storage medium (P=0.43). To assess and identify early clinical variables that are most predictive of treatment outcomes for avulsed and replanted permanent anterior teeth and to develop a model that will allow estimation of treatment outcome based on these variables, a retrospective study was designed and undertaken, where the dental trauma database was used to randomly identify patients who had sustained dental trauma on their permanent teeth leading to avulsion between 1998 and 2007. A data extraction form was designed and completed for each tooth. Demographic, diagnostic and treatment information recorded in the patient’s records, in addition to radiographs, were viewed and then transcribed and processed. The significance for each early clinical variable was assessed using a univariate logistic regression model. Only significant variables (P ≤ 0.05) were considered eligible for the prediction model and a c-index was then constructed for their respective predictive power. 213 patients who had received treatment for avulsed and replanted teeth between 1998 and 2007 were studied and only 105 fulfilled the criteria for evaluation.

Abstract: Ecological influences, observational caries epidemiological trends and associated socioeconomic and geographic dental health inequalities at five years of age in Scotland, 1993/94-2007/08 Introduction: In recent years many national Governments have called for health improvements at the population level and at the same time reductions in health inequalities. To date, dental epidemiology has concentrated mainly on tracking trends in dental health. Methodologies relating to dental health inequalities are, however, not well established. Within Scotland, over the past decade, children’s oral health improvement programmes have been established at national level. Preceding and concurrent with these developments, similar initiatives have been implemented within Greater Glasgow NHS Board. This is Scotland's largest NHS Board with the highest proportion of Scotland’s socio-economic status (SES) deprived population. Recent reports from the National Dental Inspection Programme (NDIP) for five-year-olds show improvements in dental health. The above conditions provide the opportunity to explore dental trends in more detail at geographic level within Scotland and to investigate dental health inequality methodologies within the context of health improvement programmes and overall improvements in dental health. Aim: To examine caries epidemiology data and apply and appraise a range of tests of health inequality to data from Primary 1 (P1) five-year-old children in Scotland during the period 1993/94-2007/08, against a background of health improvement programmes. Furthermore, to apply the selected inequalities tests to the caries data for a) Scotland as a whole and b) the geographic subgroups: 1] Glasgow (GGHB) and 2] the remainder of Scotland, outwith Glasgow (Not-Glasgow). Methods: Secondary analyses were performed on eight successive cross-sectional NDIP five-year-olds' caries datasets, 1993/94 to 2007/08. These permitted both SES and geographic trends in mean d3mft and % dmft=0 to be plotted for the areas: Scotland, GGHB and Not-Glasgow. The metrics selected to model dental health inequalities were: the Significant Caries Index (SIC) and modified SIC10, the Receiver Operator Curve (ROC), the Gini coefficient, the Concentration Curve (CC), Koolman and Doorslaer's transformed Concentration Index (CI), the Slope Index of Inequality (SII), the Relative Index of Inequality (RII) and the Population Attributable Risk (PAR). Odds Ratios and Meta-analyses using Generalised Linear Modelling assessed statistical-inference for dental health and inequality trends. Results: Overall, usable data was retrieved for 68,398 five-year-old subjects (n=18,174 from GGHB; n=50,224 from Not-Glasgow). In Scotland as a whole, marked SES gradients in caries prevalence and caries burden were related to the DepCat score of children’s home postcode. Between the start and endpoints of the study, the simple absolute SES inequality in mean d3mft between the most affluent and most deprived groups decreased (p<0.02), whilst mean d3mft reduced across the entire SES spectrum. Relative to the baseline year (1993), by 2007, the Odds Ratios for d3mft>0 in Scotland decreased (p<0.0001) to 0.43 (95%CI, 0.40-0.46). Although Scotland's simple absolute SES related dental health inequality (DHI) decreased for mean d3mft (p<0.02), there were no improvements in simple relative SES DHIs over this time period. Simple absolute and simple relative geographic inequalities in weighted %d3mft=0 and mean d3mft were seen when GGHB was compared with Not-Glasgow data. These geographic inequalities metrics tended to increase from 1993/94 until 1999/00. However, by 2007/08 reductions in simple absolute geographic inequality were observed, with marginal improvements in simple relative geographic inequality compared to baseline. Additionally, simple absolute and relative geographic inequality in SIC scores decreased overall against a background of SIC improvements in both GGHB & Not-Glasgow (Meta-analysis, p<0.01, respectively). By 2007/08, relative to 1993/94, Odds Ratios for d3mft>0 in the geographic subgroups GGHB and Not-Glasgow decreased, respectively (p<0.0001), to 0.31 (95%CI, 0.26-0.38) and 0.46 (95%CI, 0.43-0.50). There was evidence of a 'Glasgow (dental health) Effect', whereby GGHB children’s dental health was poorer than in Not-Glasgow during the period 1993 to 1999, after controlling for confounding factors (p<0.01). This ‘Glasgow Effect’ was no longer evident by 2007. Modelling caries data using the complex inequality metrics has given further insights into different dimensions of geographic and SES-related dental health inequalities. For example, in each area from 1993/94-2007/08, the full SIC10 distributions showed respective decreases in complex absolute DHI in affected individuals in population deciles (irrespective of SES). Simultaneously, Scotland's SII indicated that complex absolute SES inequalities decreased (p<0.02). Furthermore, in Glasgow the %PAR decreased by 24 percentage points, itself impacting on Scotland's decreased PAR. However, the RII and transformed CI indicated that complex relative SES DHI increased in each area over the period of study. The ROC, CC & RII plots were comparatively stable over time for Scotland, compared to trends in the GGHB subgroup. There was evidence of some variation in DHI, and the Gini-coefficient (for individual DHI) was counter-intuitive. Discussion: Analysis and interpretation of simple and complex absolute and relative DHI outcomes are not straightforward against a background of population dental health improvements across the SES spectrum. If equivalent absolute dental health improvements are achieved in the best and poorest d3mft groups, as %d3mft>0 and mean d3mft diminish in the denominator group it is increasingly difficult to achieve improvement in relative inequalities. Nonetheless, tests suggest that simple absolute geographic DHI in Scotland's P1's weighted %d3mft=0 and mean d3mft have improved, while simple relative geographic inequality has not deteriorated over the interval 1993-2007. Further insights were obtained from examination of the cross-sectional distributions of SIC10. These showed improvements in complex absolute individual inequality across all population deciles with d3mft>0, over time, at each geographic level. Moreover, comparison of the geographic SIC10 scores for the worst affected deciles demonstrated reductions in simple absolute and relative geographic DHI in five-year-olds' d3mft morbidity for those with the poorest dental health outcomes in 2007 vs. 1993. Furthermore, Scotland's complex absolute SES-related DHI has decreased over time when assessed by SII. Improvements in complex absolute SES-related DHI have occurred more readily than improvements in complex relative SES-related DHI. Conclusions: For the first time, these multiple tests of inequality have been applied to Scotland’s and Glasgow’s child caries datasets. Generally, caries epidemiology trends occurred slowly and smoothly, however, DHI trends from this same data tended to fluctuate (especially in the geographic subgroups). The apparent lack of consonance of the various inequalities metrics demonstrates that measurement, understanding and interpretation of population DHI trends are complicated and require knowledge of the underlying epidemiology trends. Nonetheless, with the exception of the Gini, all results provided useful information which aid understanding of DHI. The complex measures such as the SII and RII had the advantage of using all the available d3mft information within the DepCat domains and weighting results for SES within the denominator populations. Furthermore, in Scotland as a whole, the SIC10 distribution, SII and RII appear to exhibit stable DHI trends, against the background populations' dental health improvements.

Dental handpieces (HP’s) are used during semi-critical and critical dental procedures that imply the HP must be sterile at the point of use. The aim of this study was to undertake a quantitative and qualitative analysis of dental HP contamination to inform the development of HP cleaning. Preliminary validation work on protein desorbtion methods and protein detection assays resulted in boiling in 1% sodium dodecylsulphate (SDS) and the o-phthaldialedhyde (OPA) assay (sensitivity 5 μg/ml) selected for further use in this study. A quantitative and qualitative analysis of HP microbial and protein contamination was then undertaken. Before decontamination, bacteria were isolated from high speed HP’s (n=40) (median 200 cfu, range 0-1.9x104 CFU/instrument), low speed HP’s(n-40) (median 400 cfu, range 0-1x104 CFU/instrument) and surgical HP’s (n=20) (median 1x103, range 0-3.7x104 CFU/instrument). A range of oral bacteria were identified in addition to Staphylococcus aureus and Propionibacterium acnes. Protein was detected from high speed HP’s (median 1.3, range 0- 210g), low speed HP’s (median 15.41 μg, range 0 - 448 μg) and surgical HP’s (median 350 μg, range 127.5– 1,936 μg) before decontamination. Serum albumin and salivary mucin were identified on surgical HP’s before decontamination. Calcium based deposits and contaminants trapped in lubricating oil were also detected using scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDX). The efficacy of detergents and a HP cleaning solution at cleaning HP contaminants was assessed in vitro with a standard test soil and disruption of biofilms with a range of cleaning efficacies noted from each cleaning solution tested. Alkaline detergents caused a significant biomass disruption of P. acnes biofilms compared to ROH2O alone. HP cleaning solution resulted in fixation of the biofilm and blood to the surface. The efficacy of novel HP cleaning machines was also assessed using a test soil based on the data generated in this study. Efficacy varied between devices tested with one demonstrating efficient protein removal in all but 1 HP location. The data presented describes a quantitative and qualitative assessment of common contaminants of HP’s, mainly bacteria, salivary mucin and serum albumin. In-vivo biofouling levels of HP’s are several fold lower than standard test soil formulations and consideration should be given to use of HP test soil based on in-vivo data to validate HP cleaning processes. The data generated in this thesis should aid in designing dental HP test soils and cleaning regimens.