Our old golden who passed away last year had clean teeth his entire life due to bone (and other items he found!) chewing as well.
With our lab mix who has very poorly aligned teeth, we started with a professional cleaning and had some teeth pulled. She had one tooth growing out of the center of the roof of her mouth. B/c she has such a bad underbite and teeth that don't line up well, her chewing is effected and even with bones her teeth do need cleaning. We try to brush periodically, but we also bought a dental scraper and just ocassionally get in there and scrape off tartar that is starting to build around the gum line. She's not inclined toward biting us and we're careful not to poke her in the gums.