idk what you mean by socialist countries but at least in france/germany medical procedures are 100% covered, only aesthetic procedures aren't covered, for example they'll patch you up with an ugly metal teeth and not the new top of the line realistic looking tooth replica.
You also get yearly or bi yearly checkups and yearly cleaning covered. For most people it's more than enough
In Germany cleanings are not covered, neither are Periodontitis treatments and also not even basic implants, only bridges.
In the Netherlands dental work is not covered at all for adults (besides pulling teeth by a surgeon)
You would have to get additional private dental insurance which only covers a certain percentage (mostly 50-75%) and is capped at around 750 Euros per annum while costing almost the same per annum.
Source: German living in NL and now having to pay out of my backside for Periodontitis treatment no matter if in Germany or NL
You also get yearly or bi yearly checkups and yearly cleaning covered. For most people it's more than enough