Sorry to sound like a broken record - but raw meaty bones clean teeth like nothing else possibly can.
Tilly is nearly 7 and her teeth are almost perfect - I say almost cos as some of you know she had this problem when she was a pup where the lower canines were crooked - they had to be straightened and extended slightly - so they are a bit stained - but certainly nothing that would need dental work at the vets.
All my other dogs are very young still, under two - so I can't say what their teeth will be like when they are older.
I had a look at a friend's 12yr old Saluki cross's teeth the other day - he is fed raw too - perfect teeth as well.