For many years, my teeth have hurt when having sugar mixed in with my eating.
I am 57 and two years ago I cut sugar out, due to the pain and the fear of losing my teeth.

Ten years ago, my lovely Seventh Day Adventist dentist taught me to explore little brushes.
They reduced the pain and bleeding, but with a temporary increase in pain.
Before each gap brush, I dipped in various mouth wash liquids.

Two years ago I experimented with tooth picks.
I even tried a spoon handle.
The best, seems to be Boots the Pharmacist "expert DENTAL" "dental pick, scaler and mirror"
The important bit is the Scaler.
It is shaped like a Hockey Stick.
Its important to learn well how to use it.
First priority is the most painful parts.
Bit by bit it does seem to get better and better.
Second priority is the bleeding parts.
The reduction in bleeding is only noticeable after about five days rest from the pick or scaler.
The third priority is the ruff and crunchy parts that are not so bad.
Unless they are made smooth, thus close to the tooth's surface, the crystals will noticeable start to regrow after a few weeks, but they probably won't be as hard.

Boots decided not to sell it in its shops anymore!! (They may sell it online)
My new dentist shows no interest in them.
Yet the pain relief is enormous!!!
Go Figure, as they say in the USA.

At some point in time, you will likely feel that you just can't reach some bad bits.
So what I do with these, is about every 2 or 3 months, I wash my teeth with Bicarbonate of Soda.
Available from cake ingredient shops.
For at least 20 minutes, I wash them, while repeatably dipping my brush into the powder.
Then I do a normal teeth wash after that, to wash away the chemical more thoroughly than a rinse.

I still have all my teeth, and now have sugary things but still sparingly.
One tooth came out due to some damage years ago, so try to be carful in the urgancy.

Thought I would add an update 2022 8 31. Now my teeth do not bleed, when I wash them. Even if I have Sugary, the pain, is much much less. I still polish a bit now and again, with the Hockey Stick shaped, Scaler from "Expert Dental". It stills bleeds a bit, but hurts alot less. The pleasure of the improvement is still significant, but the problem, of the affect on my number 2s, is becoming more of a disadvantage, compared to the advantage ! I have since discovered that there is 3 sorts of Sugar : -Fruit Sugar, that Adam and Eve had. -Amylase I think, that is also not to bad for teeth, as an enzyme is needed, to make it sweet, and the Enzyme is made by the Mouth I think. -Cane Sugar, this one not only pains my teeth, but also is the cause of Diabetes troubles ! It sells so well, that the large amount of People who have Diabetes, still do not have the right sort of Sugars. I myself like Porridge and Lentils, with a bit of Olive Oil !! It is my belief, that the same Plaque of the Teeth, blocks the tiny Blood Channels, to the Brain Cells, eventually making worse Dementia in the Age troubles ! This seems verified in Medecine, by a Dr Attia, google "Dr Attia" "Sugar".