Didn't know about biofilms (bacterial or other) earlier. The basic idea is intuitive (which is why I gargle with salt water regularly), but googled biofilm now and found a lot of info - it is complex. Thanks for mentioning it!

Saw this:

https://en.wikipedia.org/wiki/Biofilm#Biofilms_and_infectiou...

https://en.wikipedia.org/wiki/Biofilm#Dental_plaque

The article says:

"Biofilms have been found to be involved in a wide variety of microbial infections in the body, by one estimate 80% of all infections"

I'm late to this thread, but I will chime in. I started using a waterpik about 2 years ago. My dental hygienist suggested I try it, because the gaps between my gums and teeth were starting to get deeper, about 2-3 mm. When I came back to the hygienist after 6 months, she told me the gaps were mostly 1-2 mm. I can't recall if I told her before she did the measurements that I'd used the waterpik, so I'm not sure if I biased her. In any case, I'm pretty sure I can also see the improvement in the mirror - at least my gums used to look a little inflamed at the gumline, here and there, and they don't anymore. Also it seemed I was bleeding less at my last cleaning (they usually tell me that I bleed more than average).

One more thing: my hygienist said I didn't have to use the waterpik every day, that it's fine to use it just a few times a week. So I'm trying to use it every other day now. I don't know the pros and cons of using it every day. Are there any long term studies which show that the waterpik is in no way harmful? I don't think so.

PS I didn't floss as a kid, so unfortunately I have tons of dental fillings. I started flossing as an adult, and I'm sure it helped a lot. I still floss once a day.