my four year old step son who already has four silver teeth and. has had to get two pulled has another damn cavity…

my four year old step son who already has four silver teeth and. has had to get two pulled has another damn cavity according to the dentist that went to his school today! he said that the dentist told him he needs to have it filled or pulled. I'm sorry but at age four almost five you shouldn't already have that many capped/filled/pulled teeth! he brushes his teeth regular at my house and says he doesn't at his moms. which is understood because why would she have him brush his teeth when she screamed and cried and got him upset and scared at his first dentist appointment! then let him be in pain four six months before finally taking him to get his teeth pulled and capped!