DSpace Collection:http://theses.ncl.ac.uk/jspui/handle/10443/922026-02-04T14:13:49Z2026-02-04T14:13:49ZOral Healthcare in England: Workforce Perspectives and Public PrioritiesCarr, Katherinehttp://theses.ncl.ac.uk/jspui/handle/10443/65142025-07-17T07:43:33Z2025-01-01T00:00:00ZTitle: Oral Healthcare in England: Workforce Perspectives and Public Priorities
Authors: Carr, Katherine
Abstract: The oral healthcare system in England comprises of the National Health Service
(NHS), offering a variety of services accessible to everyone, and a private sector.
However, persistent oral health inequalities and issues regarding accessibility of NHS
dental appointments suggest a system performing sub-optimally. This thesis
investigates the factors which influence dental professionals’ decisions about where
to work, and patients’ views and priorities for NHS dentistry.
Chapters 4 and 5 present data from qualitative interviews held with dental
professionals (n=17) and the general public (n=20), analysed using a framework
approach. The evidence presented demonstrates a range of push and pull factors
which influence where dental professionals provide labour, highlighting the
ideological commitment to the NHS, but that the working conditions detract from
patient-centred care. The findings from the public interviews demonstrate a variety of
interpretations of oral health and clinically necessary treatment under the NHS. The
private sector was discussed as supplementary, but raised equity concerns.
Chapters 6 introduces a preference elicitation exercise (a Benefit Trade-Off, or BTO)
to establish if members of the general public (n=1,688) are willing to sacrifice
efficiency (larger oral health gains) to reduce oral health inequalities. A series of
methodological investigations follow in Chapter 7. The results from the BTO indicate
that inequality aversion is low, meaning that maximising oral health is prioritised
relative to reducing inequalities for most. The methodological results show that how
the scenarios are presented can impact the result.
This thesis offers significant contributions to our understanding of NHS dentistry.
The qualitative studies identify key factors which drive the workforce and presents
public desires for oral health under the NHS. The BTO provides the first insight into
inequality aversion in oral health globally. Future policies need to reflect the diversity
of perspectives and be underpinned by sustainable approaches to improving oral
health.
Description: PhD Thesis2025-01-01T00:00:00ZAmalgam phase-out: what next for dentistry? Costs and benefits of the alternative direct restorationsBailey, Oliver Samuelhttp://theses.ncl.ac.uk/jspui/handle/10443/64812025-06-05T13:06:33Z2025-01-01T00:00:00ZTitle: Amalgam phase-out: what next for dentistry? Costs and benefits of the alternative direct restorations
Authors: Bailey, Oliver Samuel
Abstract: Introduction
Dental amalgam has been used to restore posterior teeth for centuries. It contains mercury
and concerns around its toxicity have mandated a phase-down of its use and an exploration
of the feasibility of its phase-out in England by 2030. This thesis explored the current use of
amalgam and the relative costs and benefits of the directly placed alternatives in the English
NHS primary care setting.
Methods
This thesis comprised three complimentary phases. Phase one quantified the use of materials
and techniques to restore posterior teeth by UK primary care clinicians, alongside their
opinions of the phase-down using an online questionnaire. Phase two quantified UK public
preferences for different aspects of posterior restorations in terms of differences in their
willingness to pay using a discrete choice experiment. Phase three was an economic
evaluation of amalgam versus the alternative restorations in the English NHS setting. A model
of restoration and reintervention was built to compare the lifetime costs and outcomes of
amalgam with the alternatives. Data from all phases were then used in a cost-consequence
analysis which quantified the differences in various outcomes and costs from the perspective
of funders, patients and clinicians.
Results
Amalgam is frequently used in NHS primary care and clinician confidence in the alternatives is
limited, with significantly higher reported post-operative complications. The lifetime
monetary and time costs to patients, funders and clinicians are significantly higher for
composite than amalgam and clinical outcomes are significantly worse. In terms of
preferences, the UK public value amalgam more than composite, with the largest relative
difference seen in low-income groups.
Discussion
An imminent phase-out of amalgam in England would lead to concerns around survival of
restored teeth, funding, patient safety and access to care, which risk exacerbating existing
health inequalities.
Description: PhD Thesis2025-01-01T00:00:00ZThe pH and Concentration of Citric Acid – Impact upon Dentine’s Topographical, Morphological, and Mechanical PropertiesMurchie, Bryan Danielhttp://theses.ncl.ac.uk/jspui/handle/10443/63802025-02-21T13:59:14Z2024-01-01T00:00:00ZTitle: The pH and Concentration of Citric Acid – Impact upon Dentine’s Topographical, Morphological, and Mechanical Properties
Authors: Murchie, Bryan Daniel
Abstract: Dentine erosion is a condition, increasing worldwide, that negatively impacts an individual’s
quality of life, which is linked to acidic fruits and beverages. However, the effects of dietary
acids on dentine erosion, particularly during normal consumption times, remains poorly
understood. This in vitro study investigates the effect of citric acid on selected dentine
properties, following short exposure times.
Polished dentine samples were subjected to simulated dietary erosion using 1% and 6%
citric acid (CA), in buffered (pH3.8) or unbuffered states (pH2.55 and pH2.06). Bovine
dentine was initially measured with contact profilometry and microhardness testing, to
establish their suitability to detect early erosion. Bovine and human dentine were
subsequently measured with atomic force microscopy (AFM) in a simulated intra-oral
environment, where samples were eroded at 20s cycles, over 2 minutes. Changes to the
morphology, roughness (Sa), modulus of elasticity (MoE), and stiffness were monitored
using AFM.
Profilometry and microhardness were unable to detect early CA erosion changes. In
comparison, AFM analysis showed dentine erosion after only 20s. For human dentine, 6%
unbuffered CA had the greatest impact on morphological, Sa, MoE and stiffness
measurements, whereas 1% buffered CA had the least erosive changes. The 1% unbuffered
group was significantly more eroded than 6% buffered samples, for all AFM measurements.
Bovine dentine was comparatively more susceptible to 6% buffered CA. Peritubular and
extrafibrillar mineral were lost at the same rate during erosion, however, the intrafibrillar
mineral remained intact for all samples, even after 2-minute exposures.
Early nanoscale surface changes to peritubular and intertubular mineral could be measured
using AFM. CA pH was more critical for erosive changes on human dentine compared with
concentration. Intrafibrillar mineral was afforded the greatest protection from erosion
compared with other sites. The different bovine erosion trends means that it cannot be
used to replace human specimens for clinically relevant outcomes.
Description: Ph. D. Thesis.2024-01-01T00:00:00ZDevelopment of novel fluoride-releasing compositesAlgadhi, Abdulaziz Abdullah Mhttp://theses.ncl.ac.uk/jspui/handle/10443/62842025-03-10T16:38:45Z2024-01-01T00:00:00ZTitle: Development of novel fluoride-releasing composites
Authors: Algadhi, Abdulaziz Abdullah M
Abstract: Due to the development of secondary caries, resin-based composites (RBCs) have short life
spans. Several modifications have been studied to overcome this problem, such as
incorporating ion-releasing fillers. In this study a previously lab-made fluoridated bioactive
glass (F-BAG) was scaled-up industrially to establish whether scaling-up affected the fluoride
release and flexural properties of RBCs containing this glass. Next, the effect of different
monomers and F-BAG concentrations was assessed on selected physical and mechanical
properties of RBCs.
Materials and methods: One batch of the lab-made F-BAG and three nominally identical but
separately made batches, made by a contract manufacturer (GTS, Glass Technology
Services, UK), were initially assessed. First, RBCs made from 50:50 UDMA:TEGDMA and a
barium aluminium-silicate glass as primary filler with 20wt% of the different F-BAG batches
added. Additionally, an RBC was made with only the primary filler added and one in which
the three GTS batches were mixed was made. Next the effect of different monomers
(UDMA, HEMA, TEGDMA) was established on RBCs containing the same concentration of FBAG. Finally, the effect of F-BAG concentration was established when the monomer
concentrations were fixed.
All RBCs were assessed in terms of degree of conversion (DOC), water sorption, fluoride
release, flexural strength (FS) and flexural modulus (FM).
Results: For DOC and fluoride release RBCs containing the GTS F-BAGs were not
significantly different to the lab-made glass containing RBCs and exhibited significantly
lower water sorption and higher flexural properties after 1 month storage in distilled water.
While the addition of HEMA significantly increased the fluoride release of the RBCs it
detrimentally affected the flexural properties over storage time. Finally, there was an
increase in fluoride release as the F-BAG concentration increased but when 30wt% or
40wt% F-BAG was added the flexural properties were reduced.
Conclusion: The experimental F-BAGs composites made in this study represents promising
results. Incorporating F-BAGs fillers in 10-40wt% showed good initial flexural properties
which decreased over storage time especially for 30wt% and above.
Description: PhD Thesis2024-01-01T00:00:00Z