Detection of Common Dental Diseases by Dental Hygiene-Therapists

Student thesis: Phd


Thesis submitted to the University of Manchester by Richard Macey for the Degree of Doctor of Philosophy entitled "Detection of Common Dental Diseases by Dental Hygiene-Therapists", February 2016.Many adult patients that attend NHS dental practices on a regular basis are asymptomatic and do not need any further treatment other than a routine dental examination ("check-up"). As the oral health of the adult population is predicted to improve further, using the General Dental Practitioner to undertake the "check-up" on regular "low risk" patients represents a substantial and potentially unnecessary cost for state-funded systems. Given recent regulatory changes in the United Kingdom, it is now possible to delegate a range of tasks to Dental Hygiene-Therapists, including the routine clinical examination. This has the potential to release General Dental Practitioner's time and increase the capacity to care at a practice level. The aim of this thesis was to determine the diagnostic test accuracy of Dental Hygiene-Therapists when detecting dental disease, explore the social acceptability of using Dental Hygiene-Therapists to manage "low risk" patients in practice and the feasibility of conducting a definitive trial. A mixed-methods approach was utilised with four inter-linked studies: 1. A diagnostic test accuracy study, which assessed the efficacy of Dental Hygiene-Therapists to detect dental caries and periodontal disease in a primary care setting (n=1899); 2. A comparative accuracy study, which investigated the ability of different dental professional groups to distinguish between photographs of malignant and non-malignant lesions (n=192); 3. A feasibility study, which examined the recruitment, retention and fidelity of using Dental Hygiene-Therapists to manage "low-risk" patients in practice over a twelve month period (n=60); and 4. A series of semi-structured interviews to determine the social acceptability of the use of Dental-Hygiene-Therapists in this role. A fifth study ran in parallel and involved undertaking a Cochrane Diagnostic Test Accuracy Systematic Review. This review informed the methods and conduct of the diagnostic test accuracy studies (studies 1 and 2). When compared to General Dental Practitioners (reference test) the Dental Hygiene-Therapists (index test) produced summary sensitivity and specificity points of 0.81 and 0.87 for dental caries, and 0.89 and 0.75 for periodontal disease respectively. When differentiating between malignant and non-malignant lesions, the Dental Hygiene-Therapist group were comparable to General Dental Practitioners for sensitivity (0.81 versus 0.77 respectively) and for specificity (0.73 versus 0.69 respectively). The feasibility results identified an acceptable recruitment rate of 34%, a retention rate of 63.33% and fidelity of 94.74%. The qualitative interviews found high social acceptability to the idea of using Dental Hygiene-Therapists to undertake routine dental examinations.These results suggest that Dental Hygiene-Therapists could be used to play a more substantial role in the management of "low risk" asymptomatic NHS patients in a primary dental care environment.
Date of Award1 Aug 2016
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorPaul Brocklehurst (Supervisor) & Anne-Marie Glenny (Supervisor)


  • Oral cancer
  • Caries
  • Periodontal
  • Dental Hygienist
  • Role Substitution
  • Dental Therapist

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