Here is a recent thread on the dental vaccine:
http://www.yorkietalk.com/forums/yor...ccination.html
It is non-core and not usually recommended.
It sounds like the vet wants you to use OraVet. It is a wax-type sealant applied weekly. We use it here. It is very safe and I would go for it. The only thing is, there are eight applications per box, so it lasts for eight weeks but what some vets don't tell you is that since Yorkies' mouths are so small, you can split one application between two weeks.
I thought you were talking about the Proheart 6 heartworm vaccine which I wouldn't recommend. The monthly preventatives are fine, however, I personally prefer Heartgard or Interceptor over Revolution.