system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] How could Voldemort kill a dementer?

I  saw an older post here where someone said Voldemort could kill dementers... But a  cursory look at the wiki implies they can't actually be destroyed?

EDIT:   I stumbled on the original post on this subreddit, researching and wondering why they  fought for him, how he 'controlled' them, during the Deathly Hallows movie.
gpt
He couldn't. Dementors aren't immortal, they're basically magical manifestations of misery and suffering. They weren't alive to begin with. The only known way to fight them is defensively, with the Patronus. 

Pure speculation, but it's possible that concentrated happiness/joy/love could unmake them. Certainly any real permanent solution would be outside of Voldemort's power.