1) It dries out your mouth.
2) The vapors of crystal meth are corrosive to tooth enamel.
3) You are probably not drinking water often enough.
I think that's about it.
No matter what ROA you take, it can still cause dental issues.
Although an experienced user taking the legal pharmaceutical version (at therapeutic doses) who practices proper dental hygiene and oral hydration amongst many other methods to prevent toxicity and overall negative health impact to the best of his or her ability, probably has less of a risk of dental issues than others who are less meticulous, wouldn't you agree? Or do you think dental issues are inevitable regardless?
@OP, I would recommend against smoking the methamphetamine just because you don't have the added risk of complications from the inhaled vapor. The oral and rectal routes are both extremely effective, both in terms of extended duration and smoother comedown, and overall less side effects. That being said, there are many who prefer to vaporize because everybody's body chemistry is different, so YMMV. What works for many, doesn't by default work the same way in you on the individual level, we all respond differently.
Take vitamins and supplements, particularly
chelated magnesium, vitamin D, coconut oil capsules, and a complete multivitamin. This in addition to a healthy hearty meal and 8 cups of water per day will give you a fighting chance against the damage methamphetamine induces.
One piece of advice with methamphetamine, it's highly dose-dependent. This goes for side effects too, especially side effects. The more methamphetamine you take, the worse side effects are going to be including risks of sleep deprivation, malnutrition, dehydration, bad hygiene including the dry mouth being discussed earlier, psychosis, sexual issues, drastic change in inhibitions, Peripheral Nervous System side effects really come out and fuck you up if you take too much and it does not feel good which is why a lot of people take CNS depressants, which can lead to developing two addictions.
I would also suggest that you get a digital blood pressure monitor and check your bp periodically.