There are a lot of perio/systemic disease ‘links’ but links per se do not always mean cause/effect. A link is an association/correlation but for each link, a lot of research needs to be done to confirm/deny these links. For example, let’s ask the question: “Does the treatment for periodontal disease help curb/prevent preterm birth/low birthweight babies?” This is a question that researchers have spent a lot of grant money studying and, in fact, the NIH (National Institutes of Health) spent about 20 million studying this question.
There are now enough high quality research studies and results have been analyzed. Pooled results from these high-quality research trials do not support the the hypothesis (question) above. For those women who were treated for periodontal disease during pregnancy there was not a reduction of preterm birth or low birthweight babies. Some of the early publications about perio/systemic links may have prematurely jumped to conclusions about some of these links and time will tell which ones are real and which ones are not.