Don't miss our weekly PhD newsletter | Sign up now Don't miss our weekly PhD newsletter | Sign up now

  Creation of authentic artificial carious lesions for dental research


   Institute of Dentistry

  , ,  Applications accepted all year round  Self-Funded PhD Students Only

About the Project

Background:

Dental caries is a worldwide issue affecting the health and wellbeing of the majority of human beings on the planet1. Severity ranges from minor aesthetic concerns to severe structural damage to teeth and associated infection. The modern ethos in dentistry is for prevention and minimally invasive intervention where necessary2. Preventative agents include toothpastes, mouthwashes and mousses; interventions involve the removal of biological hard tissue and substitution with a restorative material, with modern amalgam substitutes having a variety of therapeutic properties as well as providing mechanical integrity. Both preventative and restorative treatments require testing prior to clinical use and this typically involves the use of extracted human teeth. These are extracted either because they are untreatable or for orthodontic purposes; the former being of little use for research and the latter being in relatively short supply. When sound teeth are available, an artificial carious lesion must be created in order to test the therapeutic agent. In much of the literature, creation of such lesions is the first stage of the testing. However, there is no consensus on how lesions should be created3, 4. It invariably involves exposing a region of the tooth to acid, but which acid and at what pH? How long should the tooth be exposed for, and should the pH be held constant or should it be cyclic? Such factors, and others, will determine the nature of the lesion created and there is therefore a need for a standard approach. If the pH is too low, an erosive lesion will be formed where enamel is completely lost. At higher pH values, partial demineralisation occurs, more resembling a natural white spot lesion and thus allowing for potential remineralisation; this could, however, take weeks or even months to form a sufficiently deep lesion. 

But protocols are not the only factor determining the nature of artificially created lesions. Some people are more prone to carious lesions than others because of a fundamental difference in the enamel. Others may have diligently used fluoride toothpastes and mouthwashes, creating a more acid-resistant surface on the enamel. This makes standardisation for research purposes difficult and results in larger samples being required due to biological and chemical variation. For such reasons, bovine enamel5 has been used as a substitute for human tissue, but this is different in its composition and may not be a sufficiently accurate analogue. Another approach, that may be valid in some limited circumstances, is to use entirely synthetic substitutes such as porous calcium hydroxyapatite.

Research Aims:

There are three primary research questions in this project:

1.     What is the optimal protocol to create an authentic artificial carious lesion in an extracted human tooth?

2.     How appropriate are bovine teeth for use in the investigation of human therapeutic agents and in what circumstances might this be acceptable or even preferable?

3.     Is it possible to create a synthetic analogue for human teeth for the investigation of dental therapeutic agents?

Characterisation of the created lesions will be performed using the Institute’s unique high-contrast micro-CT system, specifically designed for dental research6.

Admission Requirements

Applicants are usually expected to hold a good first BSc honors degree of at least 2:1, or equivalent, to be eligible to apply for admission to research degrees. The exact entry requirements for each PhD will vary depending on the nature of the project.

If English is not your first language, the standard requirement for English is an IELTS score of 6.5 overall for non-clinical projects and 7 overall for clinical projects (or equivalent). More details about language requirements can be found here.

For more information on the project, please contact Professor Davis ()

For information on the application process, please contact


Materials Science (24) Medicine (26)

Funding Notes

We will consider applications from prospective students with a source of funding to cover tuition fees and bench fees for three years full-time or 6 years part-time. Both self-funded and sponsored students will be considered.
UK nationals, Irish citizens and those with settled status under the EU Settlement Scheme or indefinite leave to remain in the UK might be eligible for a doctoral loan for both the cost of tuition fees and a yearly stipend over the course of the PhD programme from Student Finance England: View Website

References

[1] Ozdemir, D., “Dental Caries : The Most Common Disease Worldwide and Preventive Strategies,” International Journal of Biology, 5(4), (2013).
[2] Banerjee, A., “Minimal intervention dentistry: part 7. Minimally invasive operative caries management: rationale and techniques,” British Dental Journal, 214(3), 107-111 (2013).
[3] Moron, B. M., Comar, L. P., Wiegand, A. et al., “Different Protocols to Produce Artificial Dentine Carious Lesions in vitro and in situ: Hardness and Mineral Content Correlation,” Caries Research, 47(2), 162-170 (2013).
[4] O'Hagan-Wong, K., Enax, J., Meyer, F. et al., (2022).
[5] Nassar, H. M., and Lippert, F., “Artificial Caries Lesion Characteristics after Secondary Demineralization with Theobromine-Containing Protocol,” Molecules, 26(2), 300 (2021).
[6] Davis, G. R., Evershed, A. N. Z., and Mills, D., “Quantitative high contrast X-ray microtomography for dental research,” Journal of Dentistry, 41(5), 475-482 (2013).

Register your interest for this project


Search Suggestions
Search suggestions

Based on your current searches we recommend the following search filters.