Wet food is not bad for teeth. You should be cleaning the dog’s teeth fairly often anyway, whether that be with brushing or using other teeth cleaning products. I’ve read that giving dogs raw meaty bones is a great way to keep teeth clean as well.
And if you’re being told that dry food is good for teeth, as it cleans them while chewing then ignore it. It’s a myth. Dry food crumbles when bitten down on, especially by the dog’s conical shaped teeth, so it’s not “scraping” the teeth at all. And a bad dog food is going to have ingredients that are more “sticky” and keep the mouth dirty anyway, whether it’s dry or wet.
