I do not believe in free feeding. Give him his food, give him 10 to 15 minutes to eat it, if he doesn't take it away until the next scheduled feeding time. And don't understand your comment about wet food and ruining teeth? Where did you hear that? It is totally not true. And honestly, would you like to eat dry kibble your entire life? I always mix in wet food, along with veggies, fruits, meat (all people food) so that they get different things for their meals.
As far as teeth, you should be brushing them daily. That is what keeps their teeth in good shape, not dry dog food