The conclusion of the abstract: "The findings of the present analysis support an association between respiratory and periodontal disease..."
Here is a link to the abstract if you care to read it: https://www.ncbi.nlm.nih.gov/pubmed/21219100
I remember when I wrote my book about gum disease 12 years ago, that there was a seeming relationship between gum disease and lung infections - and a number of other diseases as well.
Research continues. We don't draw definitive conclusions. But we also don't have to in order to take action that may be beneficial.
If farmers and ancient people knew that livestock were not good if there mouths were not healthy, it makes sense that researchers of today would start to notice this association too.
Bottom line: Just an opinion, but it would seem prudent to keep on HydroFlossing!
https://www.toothygrinsstore.com/HydroFloss-p/hydrofloss01.htm
Stay Healthy and Well!
David
PS: Coupon code HealthyApril10 will be good at either site for about a week and will stop working thereafter.