Pharmacologically, amphetamines are no worse on your mouth than regular nicotine or caffeine usage. And while cigs & coffee aren't necessarily good for your oral health, they also don't generally cause major gum disease and tooth loss.
"Meth mouth" is mostly caused by neglect, not the biological effects of amphetamines. Long-term heroin & crack users suffer the same kind of severe tooth decay as meth addicts. If you smoke meth every day, but still somehow manage to brush & floss your teeth every day, your oral health won't be any worse than the average American.
That's incorrect, at least in the case of cigarettes. According to the CDC, you have twice the risk of gum disease if you smoke versus nonsmokers. They also state that the more you smoke and the longer you smoke, the greater your risk. That doesn't directly imply a causal link, but it sure winks really obviously in the direction of one.
For some perspective, "Twice the risk of gum disease" is pretty tame. Try losing 90% of your adult teeth... That's the level of dental prohlem that lomg-term addicts have to deal with, after 5-10 years of street life. Smoking cigarettes doesn't even come close.
"Meth mouth" is mostly caused by neglect, not the biological effects of amphetamines. Long-term heroin & crack users suffer the same kind of severe tooth decay as meth addicts. If you smoke meth every day, but still somehow manage to brush & floss your teeth every day, your oral health won't be any worse than the average American.