I am having a dental done on my yorkie in 2 weeks. I actually just spoke to one of the techs/assistants there regarding this and they were very helpful. 
I asked them what type of anesthesia they used and he told me they use 
Serofllurane.  Someone had told me this is the safest type to use...and this tech told me that it is the most expensive, and that many private hospitals don't use this cause of the cost, but that Banfield uses it because its the safest and that it allows a quick recovery time for the pet. Most dogs wake up quickly and even leave walking out the door.   I feel more comfortable knowing this and I wanted share it with others. Every banfield may differ though, but this is good info to know. 
