Grounding prong broke off Scentsy Plug-In warmer... can i still use it?

I have a scentsy warmer that I use for melting wax in my bathroom. I had it plugged in my living room a while back and my daughter pulled it at a weird angle and snapped the grounding prong off in the socket. I'm not concerned about the socket, just if I can use the warmer still or not. It still has about 2/3 of the prong, but has a small piece of metal showing in the middle of it. Is it safe to use until I can afford a new one? They run about $15 +shipping, so I don't want to spend the money if I don't need to. Thanks for any help!