Oliver only eats dry kibble and gets dental treats and the vet is always happy with his teeth (he will not touch wet food other than a little bit of tuna)... I've recently started brushing his with a baby toothbrush just for my own satisfaction (I brush my dog's and just associate tooth brushing with the bath routine)... he's not too fond of it yet, but I do get in there pretty good.... it's not an absolute must, but if you want to start doing it when theyre young so they get used to it.... there are all kinds of dental treatments for cats out there and everyone has a preference