Help with Gum Boil / Dental Abscess?

One year ago I had a crown on my lower right molar (not the furthest one back but the one in front of that). At the time it was done, it was excruciating. I see a self-proclaimed "holistic dentist" (he does mercury removal, etc. but doesn't tell you how to heal with homeopathy though he sells some in his office). This tooth had a pulp cap which they explained is effective 50% of the time. It gave me continual trouble ... sensitive to heat and cold on again off again. It was okay until I recently had dental work on the left side of my mouth. Because of my sensitivity to cold air at the time, I had them numb my right side. SINCE THAT TIME, this tooth became angry all over again. It's had sharp shooting pain, dull aching pain, and the gums bled with brushing. (In fact, my gums bled from brushing all the time after I visited the dentist last year in the areas where they worked. I use an aloe-vera based mouthwash with goldenseal, etc and take a million homeopathics ... that problem has mostly resolved.) When the bleeding gums stopped, so did the tooth sensitivity to hot and cold. But now I've got a gum boil at the bottom of the tooth. THE TOOTH DOES NOT HURT but sometimes feels inflamed,taller than the rest of the teeth and the gum boil every evening becomes more inflamed like it's going to pop! Nothing is oozing from it though.

I've been using hepar sulph 30c and silica 200c which definitely helped over two days -- the gum boil was almost flat and there was no toothache. I was using several doses in a day. Then, I went one day with taking it only once and the boil returned angrier than ever. I got some hepar sulph 200 c and have been using that. There is no discomfort when using hepar sulph at either potency but nothing is bringing down the boil.

Any other ideas?

I've read that hepar sulph 200c is pushing the toxins into the skin and I may want to try hepar sulph 6c to let the lymph system flush away the toxins.

My gums are otherwise very healthy by my observation and quantified by the dentist. They are not spongy, swollen, red, etc.

I had been taking carbo veg 30c before the boil appeared. I was taking it for hair loss, constipation, fatigue after eating, bleeding gums. My general condition in the last month has been something between graphites, lycopodium, and carbo veg. I was taking all of them because I was unsure which matched best.

Anyway -- I REALLY REALLY REALLY want to save this tooth. I don't believe in root canal and I don't want an extraction. So if we can eliminate this boil, I'd be super happy!!!