Improving the Quality of Dentistry (IQuaD): A randomised controlled trial comparing oral hygiene advice and periodontal instrumentation for the prevention and management of periodontal disease in dentate adults attending dental primary care

Periodontal disease is the most common oral disease affecting adults. Effective self-care (tooth brushing and interdental aids) for plaque control and removal of risk factors such as calculus, by periodontal instrumentation (PI), commonly known as a “scale and polish”, are considered necessary to prevent and treat periodontal disease. A Cochrane review found evidence that psychological interventions resulted in improvements in oral hygiene behaviours but there is a lack of reliable evidence to inform clinicians of the relative effectiveness of different types of Oral Hygiene Advice (OHA) on the prevention of periodontal disease in adults. Similarly there is mixed evidence on the effectiveness and optimal frequency of PI. The majority of trials that have been carried out to date have been of poor to moderate quality with few conducted in primary care and a lack of patient centred outcomes and economic analyses reported. The IQuaD trial will investigate the effectiveness and cost effectiveness of the following dental management strategies in general dental practices across the UK: 1. Personalised OHA versus routine OHA 2. 12 monthly PI versus 6 monthly PI 3. No PI versus 6 monthly PI Participating dentists (60) will be cluster randomised to provide routine (current practice) or theory-based personalised (to the needs of the patient) OHA. A total of 1860 individual eligible patients will be randomised to no PI, 6 monthly PI or 12 monthly PI (310 to each group within each cluster of routine or personalised OHA randomised dentists). Clinical outcomes, assessed by gingival inflammation/bleeding measured according to the Gingival Index of Loe, will be measured at baseline and at 3 years follow-up by trained outcome assessors who are blinded to allocation, participants will be followed-up by postal questionnaires sent annually.