Re: his dentist's office
In the UK, you can only visit a doctor's surgery if you are registered there as a patient. You are generally registered with one particular doctor but you don't have to see that person for your appointment, but you can only attend that surgery for a medical appointment that is not an emergency.
The same goes for a dentist to some extent. If you choose to pay for a private dentist, then you can phone for an appointment and you just pay for that one appointment. You don't have to go back there next time, you can pick another dentist if you want to. However, we still have non-private dentists (NHS dentists) where treatment is much cheaper. In order to be seen by one of these dentists, you must register with their dental practice and you must attend at least once every 6 to 12 months for a check-up in order to remain registered with them. If you fail to attend at least once, they are allowed to strike your name from their register and you can't go there any more.
I don't really know how routine appointments work in the UK if you choose to have private healthcare/health insurance. I've never been able to afford it!
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