I've been using superglue to hold my crown in place as I cannot bare for people to see me with my front tooth. Is it dangerous?

Suzie, Why not see a dentist? Superglue can kill a living tooth. It's actually the worst glue to use because it is also water-soluble (saliva) over a short period of time. If the crown keeps falling out it may need to be redone. You are taking the risk of swallowing it, or worse, aspirating it into your lungs.

While it may hold your crown in for the time being, you are most likely doing more harm than good.  A tooth has microscopic tubes in it.  The cement/bond used to hold your crown in utilizes these tubes.  In fact, they are specifically manufactured to flow into the tubes.  By placing superglue on your tooth, your are completely blocking these tubes.  I'd recommend visiting your dentist to have this replaced as soon as possible.  Most likely the damage is done.  Every time you replace the crown, you are just adding another layer on top of what is already there and has already blocked the tubes.  Your dentist will most likely have to remove the top layer of the tooth/superglue to expose fresh portions of the tubes.  You can then be "fitted" for another crown and a temp crown can be placed.