Several posts have mentioned that an all wet diet is bad for cats teeth. With Bibi, I have to keep her on all wet (nature's menu raw) as that's what keeps her colitis in check. So my vet told me to brush the girls' teeth. My initial response was 'are you shitting me, I like my skin where it is' but Z and B are living proof that it can be done, at least with some cats, so I thought I'd share the process. It's not something you can accomplish all at once, you have to be patient and build up to it. Now, however, it takes me less than a minute per cat per day.
You need to get a special cat and dog toothpaste (we use CET) that is safe for swallowing, as obviously they don't spit. Then you either need a finger brush (goes over the tip of one finger) or a tiny little cat brush. We use the latter because my girls are pretty small cats and I doubt a finger brush would fit in Z's mouth. On the first day, just put a bit of the toothpaste on your finger at let them sniff it. That's all. Don't rush it. Do that for a few days until they're familiar with the paste. Then introduce them to the brush. For a few days just let them sniff and touch it. Then stroke their cheeks with it - they'll like this. Once they're used to having their cheeks stroked, start inching it closer to the mouth. Once they're comfortable with the brush on their teeth, add a tiny bit of the toothpaste. At first they'll probably only let you do the surface of the front teeth - that's phase 1. When they're comfortable with this, you can start pressing very gently so they open their mouths and get to the back ones.
The trick is slowly slowly, one phase at a time. It was a pain to do but both cats now tolerate it fine (I wouldn't say they enjoy it) and it takes me a couple of minutes at bedtime. I think that's worth preventing dental surgery in the future. Of course, there are some cats who this simply won't be possible with, but I thought I'd lay out the steps for anyone who wants to give it a go. Good luck!