BackgroundMaximising health gain for a given level and mix of resources is an ethical imperative for health-service planners. Approximately half of all patients who attend a regular NHS dental check-up do not require any further treatment, whereas many in the population do not regularly attend. Thus, the most expensive resource (the dentist) is seeing healthy patients at a time when many of those with disease do not access care. Role substitution in NHS dentistry, where other members of the dental team undertake the clinical tasks previously provided by dentists, has the potential to increase efficiency and the capacity to care and lower costs. However, no studies have empirically investigated the efficiency of NHS dental provision that makes use of role substitution.Research questionsThis programme of research sought to address three research questions: (1) what is the efficiency of NHS dental teams that make use of role substitution?; (2) what are the barriers to, and facilitators of, role substitution in NHS dental practices?; and (3) how do incentives in the remuneration systems influence the organisation of these inputs and production of outputs in the NHS?DesignData envelopment analysis was used to develop a productive efficiency frontier for participating NHS practices, which were then compared on a relative basis, after controlling for patient and practice characteristics. External validity was tested using stochastic frontier modelling, while semistructured interviews explored the views of participating dental teams and their patients to role substitution.SettingNHS ‘high-street’ general dental practices.Participants121 practices across the north of England.InterventionsNo active interventions were undertaken.Main outcome measuresRelative efficiency of participating NHS practices, alongside a detailed narrative of their views about role substitution dentistry. Social acceptability for patients.ResultsThe utilisation of non-dentist roles in NHS practices was relatively low, the most common role type being the dental hygienist. Increasing the number of non-dentist team members reduced efficiency. However, it was not possible to determine the relative efficiency of individual team members, as the NHS contracts only with dentists. Financial incentives in the NHS dental contract and the views of practice principals (i.e. senior staff members) were equally important. Bespoke payment and referral systems were required to make role substitution economically viable. Many non-dentist team members were not being used to their full scope of practice and constraints on their ability to prescribe reduced efficiency further. Many non-dentist team members experienced a precarious existence, commonly being employed at multiple practices. Patients had a low level of awareness of the different non-dentist roles in a dental team. Many exhibited an inherent trust in the professional ‘system’, but prior experience of role substitution was important for social acceptability.ConclusionsBetter alignment between the financial incentives within the NHS dental contract and the use of role substitution is required, although professional acceptability remains critical.Study limitationsOutput data collected did not reflect the quality of care provided by the dental team and the input data were self-reported.Future workFurther work is required to improve the evidence base for the use of role substitution in NHS dentistry, exploring the effects and costs of provision.FundingThe National Institute for Health Research Health Services and Delivery Research programme.