Our flock of Butterflies love their big bones. There are other sites, people, which suggest not to give these bones to dogs, bones from beef, and other large animals, or in other words: knuckle bones, soup bones, etc, as they may break the dog's teeth. But I find these bones as a recreational bone very useful. They seem to be softer when fresh, I cut all excess meet, or ligaments, cartilage off, and after a few days to a week I discard them, as they harden up.
All our dogs have by now white teeth, and do not need any dental cleaning at all. And they certainly don't have to put up with human toothbrush procedures. they are cleaning their teeth dogie style!!