I have a friend who does mdma regularly (like once every 3 months). Suffers from bruxism too. When he goes to the dentist, he can tell he's a mdma user.
You're free to waste your health as you wish (also mdma lowers t-cell rate in the blood, they never get back to normal afterwards, a japanese man taking multiple Es a day even died of immunodeficiency). Personally I prefer a good brewage of ipomea heavenly blue or some hawaian baby woodrose.
Edit: Source: https://www.youtube.com/watch?v=RnptUdyDUKI&t=30m (timelink @ 30mins). It is said mdma is neurotoxic can induce permanent damages and trigger chronic depression. Scientist: "I think mdma like no other drug has a much higher neurotoxic potential". Then the dubbing voice takes over. Activates subtitles. "MDMA is a special case [among other ego distorting drugs]. It is delicate to give recommendation of use for this drug and if somebody asked me my opinion I would say it's best to stay away from it".
I’m surprised he lived long enough to die of that.
MDMA is associated with bruxism but generally not prolonged past the day you take it/day after. Most users wouldn’t take it weekly (I knew some who would) or even monthly, let alone multiple doses a day.
YouTube videos are a poor source of information, I’m afraid.
Once every 6 months max.
It can cause brain damage. Serotonin syndrome, depression and a whole host of things.
Yes, you'll grind your teeth while on it. (Not a year afterwards)
A hammer can also hurt you if you smash it into your face. A car will kill you if you drive dangerously.
It's a chemical. It can be used with a safety profile that makes the positive benefits worth it (like any drug or activity)
Responsible use of anything is important.
The thing is with MDMA is doing it daily won't produce the same effect each day. You run out of the brain chemistry it causes you to release all at once. There's an upper limit to frequency in exchange for pleasure and it is quite low.