Purina Busy Bone Dental

I'm a big fan of the Purina Busy Bones, as they seem to keep Izzy and Emma occupied for quite a while, and seem to be keeping their teeth nice and pearly white. I tried the new Busy Bone Dental that I found at Target yesterday, and I have to say, I was kind of disappointed. Emma had hers gone in about 10 minutes, and Izzy finished soon after. Apparently these new Dental Bones are meant as daily treats, and thus don't last as long. It's partly my fault for not reading the packaging completely, but from my point of view, a Busy Bone should last a while...you know, keeping your dog BUSY! Aside from the short life span, I don't think these tasted very good, as Emma didn't even try to steal Izzy's away after finishing her own. And she'll eat just about anything. If anyone has tried these, let me know what you think - are they good at keeping your dog's teeth clean? Because that's my main concern!