If you have acute dental issues then you'll get a time virtually instantly.

There is no such thing as a non-acute dental issue. A filling can wait for a couple weeks max before possibly becoming a real acute issue. You are only aware of the cavity until it starts to hurt, which means already late.

A good rule of thumb is to have a CT scan every year for early detection. I have been doing it for the last 5 years and boy it did save me from lots of pain. Lots of cavities are hiding unseen and with no pain.

"CT scan for cavities" speaking of over-diagnosis... (Not forgetting the risk of CT scan radiation)

Brush your teeth, visit your dentist. Yes some might do an x-ray for hard to see areas. But this is not rocket science

CTs indeed sound a little overkill. Aren't cavities entirely avoidable? As long as you can afford a healthy diet and have water/toothpaste you won't develop any?

You're supposed to go to the dentist one or twice a year even without any problems.

Actually, in some places you have to pay a premium for your insurance/social security if you don't visit the dentist at least twice a year.

These control visits qualify as non-acute, and they greatly reduce the amount of acute dental issues you might have.

When I book a dentist or an oral hygienist, the first available times are usually at miminum 8 months ahead. The cost is 60 €. This is at the public healthcare.

Granted, this is another Finnish city, not Helsinki.