Can it break by just wearing it and not using it to turn into a werewolf? If it breaks, can you summon Hircine for another one?

I'm not sure - most artifacts are only "worn" when you use their active ability, but as far as I know, Hircine's Ring only has passive (when equipped) abilities.

If you use to cast Lycanthropy, then yes, it will wear it down. If you just use it passively (i.e. don't cast Lycanthropy with it) then it'll last indefinitely.

ok, thanks. I rarely turn into the werewolf anyway. It's weaker than my human form.