My dentist brother advised me against root canal work as he said it was not uncommon for it to go tits up - Have it extracted he said - he had retired by that time !
My brother was a dentist until retired and he made a decent income from an almost totally NHS practice however he had some friends in high places who probably didn't pay.
He recalled to me that on one occasion after having completed a procedure with the area 'circuit judge' he then entertained...