As one responder pointed out, the infection is a BFHD - screw up addressing that and the risks are very serious. On that basis, I can see the need for the antibiotics to address the risk. Ok, fine.
Dental practice has changed a lot as far as I can see - my first dentist as a kid was a friend of my parents. I hated him, which was unfair - the tools were primitive, the needles dull (felt like a 12 gauge barrel moderately sharpened), etc. It made for a longish period of avoiding dentists, and my self-care was not good. The dentist I have now has a good crew - the dental hygienists have much better education and do a great job with the work and with educating me.
With increased knowledge has come increased specialization. This is contributed to by the risk of malpractice. Some doctors are really awful and deserve every bad thing they have happen to them. I've seen the aftermath on someone with whom I used to work - that "oral surgeon" was a butcher and about the only thing I can say in this forum is the patient population would be better off if someone took a ball peen hammer to his hands.
The other problem with malpractice is anesthesia. It is, as far as I know, the worst area for malpractice and high risk. As one deals with older patients (over 40 or so), the risks are worse. 60+ like many of us members? Ick - even those of us with pretty active lifestyles and aggressive fitness programs.
Then we have the insurance companies, who are slow with referrals and decisions. Insensitive to your wife's discomfort, compounded with a modest number of specialists. I recall you live in a relatively rural area - it takes a decent population density to support some specialists, so referral options near you are probably limited. Same here, but not as bad - and I would still have to go 180 miles or so to Spokane for a lot of procedures.
Put that all together, and you have a perfect storm of bad facts, leading to a bad outcome. I feel sorry for you and your wife, because a few days of that is all the misery one should have.
