I have never been to a dentist who knows **** about any medical terminology or healing anything. Drill and fill is what they've learned, even the mercury free dentists.
Quick question, the tooth that was hurting, but now isn't, does it have an Amalgam filling in it by chance??
Also, have you tried swishing and gargling with plain hydrogen peroxide for cankers or weird bubbles/swelling? If there is some kind of infection that is causing blockage, seems like disinfecting the mouth would help. Swishing and gargling with plain old baking soda is also anti-bacterial, anti-fungal.
You sound very worried to me, but I can't really find anything in your posts that make me think you should be worried about a heart damaging infection.
Please don't think I'm trying to downplay your concern - I just don't want you to worry OR spend a boat load of hard earned cash on a dentist who will charge you $300 bucks to do ex-rays and a cleaning, then say everything looks good and send you out the door because you don't have insurance.