I've had around 4 dentists over the space of ~3 years since my long time one retired, and they all seem to have vastly different opinions about what dental work

I've had around 4 dentists over the space of ~3 years since my long time one retired, and they all seem to have vastly different opinions about what dental work is necessary, preventative, unnecessary. With my original dentist I never had any fillings. As soon as the next dentist came in she recommended 2 fillings and then a later 3rd. Of these filings, one didn't even require anaesthetic for her to drill and complete the filling. After this dentist left, the next had a policy of, if it isn't causing you pain, filling it is unnecessary (because you often have to drill a tooth slightly to fill it, damaging the tooth worse). That dentist eventually moved on, and two of those earlier fillings fell out within a month of each other (really not a good time having to carefully eat around these teeth, one on each side of my mouth), and the new dentist gave me two root canals because the roots in the affected teeth had apparently died (potentially my fault, for delaying an appointment due to the timing being several weeks before I was to leave uni). Several months after these root canals had been completed, I had an abscess on one of these teeth, but it passed after a weekend of paracetamol(?). One of these root canal'd teeth then further broke, and the dentist recommended having a crown placed on the tooth, I did enquire about simply having the tooth removed because it had become so much hassle, but the dentist was really against it. Due to my situation of being at university, and having to travel several hours down the country for each dental appointment, and the need for 4+ appointments to have 2 crowns I opted to visit a dentist local to my university. They ended up recommending removing both the root canal'd teeth (one specifically because the tooth had broken below the gum-line, so it should not be crowned/filled) and they also applied dental sealant to an unrelated tooth. This dentist also stated, if you have an abscess on a root canal'd tooth, that it has become infected, and that infection is unlikely to ever go away, it will simply come back when your immune system is weak (at the initial abscess I had been doing a 48 hr all-nighter for a large assignment deadline), so it's best to have these teeth removed. tldr; Dentists in my own anecdotal experience can have vastly different opinions of best practise. I'm also UK based, so dental treatment is relatively inexpensive, due to the NHS funding a large part of it.