its really easy to understand. dentists are self -employed, there is not enough contracted work to cover the populations needs. NHS england issues contracts but for decades now has not suitably increased the contracts they issue because to contract more work costs more money. So dentists have to something else with their time, either private practice or teaching or working abroad for some part of the year etc.
Dentists used to overdo giving fillings to people (kids) when it was paid per filling, in the seventies and eighties. There were lots of complaints about this and that’s probably why it was changed.
