Scottish health researchers looked at the general population (n-11,869) and followed a large subset with questions about their oral health. They asked about frequency of dentist visits, tooth brushing, and controlled for many co-variables such as general activity, hypertension, smoking, height and weight. They also collected blood for studies of C-reactive protein as a marker of inflammation. They removed from the analysis 3685 participants who were edentulous (no natural teeth) and 386 with existing cardiovascular disease.
This elaborate and lengthy study showed that toothbrushing is associated with cardiovascular disease, and subjects who brushed their teeth less than once a day had a 70% increase in heart disease compared with people who brushed twice a day. The inflammation that periodontal disease causes is directly related to increased C-reactive protein and increased heart attacks.
Leave it to the Brits to remind us to brush and floss every day.