Afaik, rarely an unattended tooth infection can break through to the sinus and even cause sepsis https://www.mayoclinic.org/diseases-conditions/tooth-abscess/symptoms-causes/syc-20350901. Also rarely an infection in the lower jaw can spread down into the neck, causing rapid swelling that if untreated can cut off your breathing and suffocate you https://my.clevelandclinic.org/health/diseases/23457-ludwigs-angina. Though I’m not sure why the latter is named Ludwig’s Angina since I don’t think it’s associated with heart pain.
TLDR: small risk of dying if a dental infection isn’t treated and infection spreads
I don’t like those mechanical/timer ones. Especially the ones with a push button top, always felt like I had to smack the button several times just to get twenty seconds of water.