Tooth filing is the reshaping of the teeth through the removal of a part of the tooth. This is not the same as "vampire teeth," which are generally caps added to the teeth.
If you go to a dentist, risks are minimal and will be explained to you in full. If you do it yourself, you risk permanent damage to the teeth. It hurts slightly less than getting a tooth drilled—anesthetic is often not required.
Strangely enough, tooth filing can reduce your chances of cavities and similar dental complications. This is thought to be one of the reasons that tribal cultures performed the procedure.
It should be noted that reversal is extremely expensive.