Gum disease stage 4

The NHS dental costs pay something towards a deep clean by your hygienist if your dentist deems it necessary. I had 2 done, one last year, one this summer. Can’t recall how much I paid each time offhand but it was c. £100. I think you must be going fully private?

I’ve paid £450 for a deep clean

That certainly sounds as though you are paying fully private as Urmstongran says. If you search for dental pocket treatment it will give you an idea of what treatments are available.
Hopefully someone on here ‘in the business’ will be able to offer some guidance.

Thanks for the replies. I'm in denplan so hygienist appts are included but my dentist referred me privately as they couldn't do any more themselves. Just so expensive !

l took the liberty of asking my recently retired husband ( last year ) what advice he would give. At your level of disease it is so variable and unpredictable as to outcomes . periodontal disease is on going and very specialised. Not like root canal treatment where you have a problem and after the treatment course it ends the problem.The NHS dental hospitals would be where you would go for an opinion but of course they are few and far apart and will have long waiting list. If it were me
l would probably ask ( and no doubt pay for) some time to talk to the specialist as to what is the best and cost effective course of action given the state your gums are in. What is the best outcome you can hope for and what is likely to happen if you do not carry on with the deep cleans. Ask him to be honest about the likely cost and outcome. Are you likely to loose some of your teeth however good your oral hygiene is? Your general health will also have some bearing on it too. You can also go back and ask your original referring dentist his thoughts. Taking about money and cost benefit are something dentist do as most people have financial constraints. l hope this helps abit.

Years ago I was referred to the Eastman Dental Hospital and had my teeth/ gums cleaned for free on NHS

Deep clean £70 and pence (40 or 80p) I can't quite remember. On NHS, no limit to number of cleans.

Thanks for the replies and thanks very much to 2420mags for the detailed and helpful reply. Much appreciated.