Oh honey I feel for you and know just where your at! My husband also came from a family of little means and dental care was just never addressed. Then I started workinging for a dental practice. I saw all sorts of patients of every age come in with terrible problems from negelect. I could not pursuade my hubby to get his teeth cleaned...and I worked there! Then one day his face swelled due to a nasty fistula...that did it...but by being closed minded and thinking if it doesn't hurt don't fix it...he ended up with two extractions, one root canal and several large fillings.
There could and very well is alot going on in your hubby's unattended mouth.
All that said, it has been widely researched and proven that the various bacterias in the mouth that make their way into the bloodstream (by way of swollen bleeding gums that surround teeth that are "caked" with plaque and calculus) affect the heart.
My best advice is to be strong and most importantly more stubborn them him! Take a peek at the American Dental Association website and gather your "ammuniton" you will find all the facts you need to plead your case. I send the best of luck to you and by the way... we're still married after 15 yrs. :-)