Periodontal surgery or extraction?

[thoroclock]

I recently got referred to a private periodontal specialist due to advanced gum disease. I had the consultation yesterday and have been told I need gum surgery in 3 locations, including bone grafts due to severe bone loss of up 60%. In these areas I have pocket depths of between 6 and 9. Two areas in the back corners of my upper jaw, one in the back lower jaw.
The cost will be £3,500 which I haven't got and will have to borrow. I have been told that after surgery, my teeth are likely to be more sensitive and the 'triangle' gaps between the teeth bigger and more likely to trap food. It won't stop the disease and my normal dentist said that the surgery will give me 5-10 years longer with my teeth before they're likely to fall out anyway. I've asked whether removal of the back ones now would make more sense as £3.5k seems a huge amount of money for just 5-10 years before the inevitable happens. The specialist said implants would be more expensive and I'm young to be considering dentures. I'm 46.
I don't know what to do.
Has anyone any advice or experience that would help me decide what to do?
Thank you.

Forgot to add - I see my hygienist every 3 months for deep cleaning. The specialist said my oral hygiene is great and can't really be improved, the hygienist is doing a great job too, the only way to stop the gym disease advancing is the surgery. (or extraction)

I'd have extractions. An upper denture for the back teeth on the top set would be valuable and on the lower at the back of the jaw I don't think I'd bother, personally but it's up to you. If you can't see it, don't replace it is my motto. At least not until fully healed.

I have a partial denture for my front side teeth on the top (a plate with four teeth - two either side). Nobody notices and I get compliments about how lovely my smile is. That's an NHS denture too so a private one would be much better quality, I'm sure. I don't need adhesive as the suction does the job but I do use adhesive when I know I'm going out to eat or about to eat something tougher like steak. I live a normal lite.

And I'm 30 with periodontal disease.

Which teeth are affected?
If it were me I’d do everything to preserve 6 forward but losing 7s and 8s would worry me less.

Because it might not work that well or give you that much time and is very expensive I would also only preserve visible teeth.

It's my upper wisdom teeth and the 1 or 2 next to them. (Sorry, not sure of the proper numbers.)
And my lower wisdom tooth and the one next to it on the lower jaw.
I keep reading that there's nothing like your original teeth and to avoid dentures at all costs, but are they really that awful compared to what I've got?!

I was in the same position as you when I was 32. I had 9/10mm pockets I had the surgery. I’ve kept my teeth with some intervention and had my first extraction this year at age 50 (after trying a root canal to keep it in my head). However I did have money. The extraction was my back tooth as it was v infected. If you can afford it I would do the surgery and see a periodontist twice a year without fail and keep up with your hygienist.