Hi there I'm so sorry to hear about Albert, when he had his dental did he have any form of general anaesthetic ?
A lot of vets have a standard general anaesthetic cocktail that they use on their daily operations this sometimes contains a drug called Domitor .
As I understand it one of its primary uses is to help stopping animals regurgitating whilst under anaesthetic, but has this is not the case with Guinea pigs
number 1 it is not needed.
But number 2 and more important Domitor has the ability to store itself in the animal's body and reactivate causing drowsiness and loss of muscle coordination
this is especially the case in Guinea pigs and the reason it should never be used. Although it doesn't always happen if it does happen , to A Guinea pig that isn't the middle of eating, the effect is the piggy chokes to death
Several years ago I lost a young boar to this drug , also I have had several instances of pig's not waking up properly for up to 36 hours, (some people report longer)
You may also remember the case a couple of years ago with "lavenderjade", a vet did a dental on her pig, and Domitor was used.and the pig died soon after
It may be an idea to find out of your vet it, tour has been used on Albert