Aim and methods: The evidence-based approach, voted in January 2007 as one of the 15 most important medical advances in the last 166 years, has increasingly shaped medical practice and education. In this paper, we apply the evidence-based approach to evaluate the aetiology of periodontitis; for comparison, we provide a brief description of the evidence-based method applied to the study of cardiovascular disease aetiology. We then discuss the challenges and opportunities to enhance the evidence base for periodontitis aetiology.
Results and conclusion: While evidence for medical treatments has mostly come from clinical trials, evidence for primary prevention in medicine has largely emerged from cohort studies evaluating disease risk factors. The high cost of conducting large cohort studies makes it challenging to fund these investigations, particularly for primary dental outcomes such as periodontitis. Studies of periodontitis outcomes integrated into larger ongoing cohorts provide one way to overcome this problem. Other potential barriers to the conduct of these studies include outcome definition, prevention of bias, data analysis, and the focus on teeth at risk (rather than people at risk) of the outcome. We analyse these questions and provide possible solutions. As many of these issues are generic to dentistry, possible solutions can improve the quality of future studies and the evidence base for primary prevention in dentistry.