I shared this with a biostatistician friend and he replied: There has been epidemiologic evidence of associations between periodontal disease and several disea

I shared this with a biostatistician friend and he replied: There has been epidemiologic evidence of associations between periodontal disease and several diseases/outcomes, including heart attacks, strokes and (in pregnant women) premature and/or low birthweight babies. Clinical trials of treatments for periodontal disease have thus far not shown any benefit in terms of these outcomes. For example: https://www.ncbi.nlm.nih.gov/pubmed/19701034 https://www.ncbi.nlm.nih.gov/pubmed/19701034