It’s pretty unbelievable that in the 21st century, many people literally can’t find a dentist. Toothache is agony, so if someone has problems, they may be tempted to tie the rope to the door and slam it etc. NHS has info on how to find a free dentist, but with huge backlogs since COVID (and government underfunding), often you’ll have to go private, which can be very expensive (too much for many people on low incomes). You can raise concerns at your local integrated care board. In emergencies, you can visit your local A & E.
Dental insurance plans are popular with zero interest, but these have to be arranged through your dentist, and are still extremely expensive (and many people won’t qualify). It’s often simply a way to get you to spend thousands of pounds on treatment you don’t need (like tooth whitening) and to spread the cost (no good if you lose your job midway). All dental insurance obviously is designed so you’ll end up paying more. But if you want to take this route, HSF is a nonprofit (set up before the NHS) and terms are far simpler and fairer than most. You’ll have to pay in before you get any benefits, but you will get money back off treatment (and other medical care like complementary health treatments if they qualify).
Dentaid is a charity that offers free dental care to people who are homeless. It has seven mobile units nationwide, and also offers help to abuse survivors, refugees, cancer patients, recovering addicts and communities where people struggle to access good dental care.
Community Dental Services is a community interest company that is referral only, offering help to people in East of England and the Midlands, with 98% positive ratings. It has several clinics including ones for mobile use and in prisons.