Other outdated yet still routine dental practices include polishing of teeth during checkups for any justification other than cosmetic reasons
My bugbear with dentists in the US (after living my first 30 years in the UK) is that they all continually hassle me to have my wisdom teeth removed. Said teeth have never caused me any problems and are all through the gums. I can only assume it's dogma or an opportunity to bill insurance for costly unnecessary surgery.