The results of a recent Cochrane review led by the research team for the Effective Practice and Organisation of Care (EPOC) Review Group, found that incentives in remuneration systems changed the patterns of care provided by dentists in primary care. Fee-For-Service (FFS) remuneration led to increased activity levels, whilst per capita payments led to under-treatment. However, the quality of the evidence was poor and further research was recommended, particularly during natural experiments where changes to remuneration systems were planned. In addition, the EPOC review argued that attention should be paid to the impact that provider remuneration had on patient related outcomes. Further evidence from changes to the NHS Dental Contract in England and Wales, showed that FFS payment systems incentivised treatment over preventive care. This has led to growing criticism of the current England & Wales dental contract, which was introduced in 2006. As a result, the Department of Health (DH) in England began piloting a new NHS dental contract in 2010, with an emphasis on prevention". Similar concerns have been raised in Northern Ireland. Following escalating pressure on the General Dental Service budget, the Health Board has decided to pilot a new model of delivery between July 2014 and December 2015. This will be based on a prospective payment system (per capita basis), rather than a retrospective payment system (FFS) and will focus on containing the costs of NHS care, improve the quality of care and broaden the population coverage to reach marginalised groups. This presents a unique opportunity to undertake a methodologically rigorous and affordable evaluation of a natural experiment using an experimental design to determine the impact of changing a remuneration system. This will enable the research team to examine the impact of this change on the productivity and quality of care delivered, thereby linking this research programme with the existing HS&DR grant (11/1025/04). The outputs will also directly address the gaps in the evidence base identified by the EPOC review and support policy makers across Europe who are grappling with the problems involved in redesigning dental services. The aim of the proposed research is to evaluate the impact of a change in the system of provider remuneration on the productivity, quality of care and health outcomes of dental services. The objectives will be to measure changes in activity and costs over the different phases of the pilots; examining productivity, the service mix of key indicator treatments, time spent by dentists delivering patient care and co-payment income. In addition, the research will assess dentists' and patients' views about the extent to which changes in remuneration affect delivery and quality of care, measure patient reported oral health knowledge, attitudes and behaviour and patient rated oral health outcomes and quality of care. The research team will utilise Realistic Evaluation to examine the underlying theory about change and will build on the conceptual framework developed as part of the NIHR SDO-funded study and empirical approach to productivity utilized in the HS&DR study (11/1025/04). Three work-streams are proposed (WS1-WS3), based on a randomised controlled trial methodology to compare activity data from test and control practices before and during the change to per capita payments and after the return back to FFS.