It's a myth I believe, that hard crunchy kibble is good for dogs' because it keeps their teeth clean. It will rub against teeth a bit but it also will stick here and there, just as it sticks on our teeth when we eat something crunchy. And it doesn't really remove plaque properly anyway.
When you think that there are so many brands of dry dog food out there which are not really great for their general health (look at the ingredients!) then a home cooked healthy diet has to be better.
If you're not sure Boo is getting all the nutrition he needs from home prepared meals, then you can add a good nutritional supplement.
You would have to do some research to find the right one and balance his diet with it so as not to give him too little or too much -or you could ask his vet for advice.
If the vet wants to sell you an expensive one, you can get it once, check out the quantities and ingredients, then go find another online or elsewhere which is cheaper for next time.
The best way to keep Boo's teeth healthy is to brush them regularly with a veterinary toothpaste. That usually comes with a special brush with two ends. One end is a small brush head, and the other is larger.
Then you have to get him used to doing this every evening before bed.
Another option is he could chew on dental chews. But I am a bit concerned about those chews. They don't suit all dogs, and can be a choking hazard. It depends how he behaves with them. But don't leave him unattended while chewing on one.
I was a vet tech for 12 yrs. I would recommend brushING his teeth. In actuality. ...hard food isn't that big of a help for the teeth anyway.