Just a word of warning re dry food. I fed my two cats on it for many years, after starting them off on wet food - I was out most of the day as they got older, so I left dry food down all day.
I honestly think they become addicted to it. I haven't checked ingredients recently (sugars?) but mine were on things like Iams and they seemed to be constantly going to their bowls to "top up" - not really the natural behaviour of a cat, which would normally eat a couple of times a day as it caught prey.
They got fat, despite having access to the outdoors during the day. And then the older one got diabetes. I did some reading and discovered that there's a possible link between dry food and the development of diabetes so I immediately changed them to high quality wet foods (Applaws etc). Sadly, my poor boy didn't respond to the regime of twice-daily insulin injections - he never felt satiated and would miaow for food constantly - after a year of watching his quality of life decline, I let him go.
I would never rear a cat on an exclusively dry diet now. Cats have trouble processing carbohydrates and most dry foods are high in carbs.
As for the tooth-cleaning properties - I asked my vet and he asked me if I'd ever watched cats eat dry food...he's right! They don't chew it; they may snap through bigger nuggets but their teeth aren't being cleaned. He also reckoned that the ingredients sprayed on to the surface (to make it palatable after so much processing) probably contained sugars of some sort, so were likely to do more harm than good.
I know we have to compromise. Few of us can manage to feed an entirely natural diet after all - but I would hate to see another poor cat end his days as my Rowan did. He had always been a lean, fit active cat while on wet food - it was only when I changed to dry that he became fat.
However you decide to feed them, make sure they have access to lots of fresh water at all times and try to keep their weight down, especially if they're going to be indoor cats. Enjoy your kittens!