Meat bones

How often can I give Lucy marrow bones? I picked up a package at the pet store today to help clean off her teeth (the vet wants $500 for a teeth cleaning...eep! I'll do it, but not before trying other avenues!) She's going to town on that thing, scraping like crazy, so it seems to be working--but how often should I do this?

Once a week? When I notice it getting bad? As a special treat?

And do I take it away at a certain point?

You can give them once a week as a treat. My doga are raw fed and get all kinds of bones with every meal. I love the big soft rib bones from cow or deer carcasses.