Black cavity smile. Meth mouth is characterized by large black cavities at the gum line of the front teeth. The cavities get large rapidly and often do not hurt until it is to late to fix them. The pattern of decayed teeth, the dry mouth, and the black cavities are often associated with the use of meth.
Your worst nightmare. One of the ingredients of crystal meth is gasoline or turpentine to 'cook' the drug and give it potency. That ingredient will literally eat away at your enamel and your life. Most users are too high to even care about the damage that they've inflicted upon themselves or they're teeth. Meth destroys lives. If you have used it- stop. If you're thinking of trying it- don't!