The first point (gum disease can cause health problems) is most likely true, even if just intuitively, but they would have to be pretty serious to reduce life e

The first point (gum disease can cause health problems) is most likely true, even if just intuitively, but they would have to be pretty serious to reduce life expectancy by 7 years - even smoking reduces it by 'only' 14 years, and I'd be hard pressed to believe that not flossing is half as dangerous as smoking. The second argument is a classical cause/effect thing. I can't imagine that tooth diseases increase heart diseases by 100%, but I can very easily imagine that people with certain habits (eating lots of cheap unhealthy food with much fat and sugar) suffer from both. Then again I don't know anything about this field, if there is any research that confirms your arguments I'd be surprised but interested.