The research activities of the Clinical Trials Unit (CTU) are diverse.

A core focus of our research is to test the efficacy of oral health care products designed for the prevention and/or treatment of oral conditions or diseases including dentine hypersensitivity and associated toothwear and gingivitis. Studies are often initially conducted in vitro before moving into in situ and in vivo models to determine efficacy. While in vivo studies are the gold standard for intervention trials they are not practical for all oral conditions. For example, it is very difficult to measure the preventive effect of a toothpaste on erosion in the oral cavity. Using in situ models developed by this group problems of measurement are overcome as dentine and enamel samples can be made and measured in the laboratory, subjected to an intervention such as toothpaste and then inserted into an orthodontic appliance and worn by a study volunteer. Thus, treated samples are exposed to the normal oral environment, but can be removed again at the end of the study for measurement. However, we are also developing in vivo methods to visualise and ultimately quantify erosion and changes in dentine that occur during dentine hypersensitivity, so that in the future interventions can be tested on living teeth in the oral environment

Another recent research theme has been to conduct randomised clinical trials to investigate new uses of plasma rich in growth factors (PRGF) an autologous technology that enables the regenerative potential of platelets and fibrin network to promote tissue regeneration. PRGF is already used routinely in implant surgery, but there are a large number of other potential applications, including the treatment of dry socket and in periodontal surgery.

Periodontal disease is another focus for the CTU. It is a highly prevalent condition affecting around 50% of the population, which can result in tooth loss if untreated, and is known to negatively affect quality of life. However, there is a large variation in prevalence figures for different age groups and to better understand the prevalence of this disease and the risk factors, the CTU has recently undertaken a large study in the South West of England, and is currently co-ordinating a study in 7 European countries. These studies investigate not only periodontal disease prevalence and risk factors, but also toothwear and dentine hypersensitivity to better understand the relationship between these oral conditions and their risk factors.

In addition to the negative effects periodontal disease has on the oral cavity it is now known that the periodontal bacteria can enter the blood stream and may result in systemic disease. One of the diseases that has been associated with periodontal pathogens more recently is Alzheimer’s Disease. Studies have shown periodontal pathogens in the brains of Alzheimer’s patients, and tooth loss has been correlated with Alzheimer’s disease, but more work is needed to substantiate the published data and confirm if periodontal disease plays a causal role. In collaboration with a dementia research group, we have just completed a preliminary clinical trial and demonstrated that periodontal interventions can be employed successfully in those with Alzheimer’s disease and are now planning a follow on feasibility study and randomised controlled trial. In parallel we are conducting laboratory experiments to try to identify which periodontal pathogens are present in the brains of Alzhiemer's patients, and in which areas of the brain to add to the evidence that suggests their presence is causative of the disease in at least some sufferers.