Question
My Periodontist says quitting smoking cannabis is the only way to keep my teeth. Do I have to quit?
Answer
Smoking anything with tobacco trebles the chance of a poorer forecast for your teeth.
Sounds like your Periodontist is recommending the best methods of increasing your chance of helping you keep your teeth.
There is established science and we can now confidently say that it is dose-dependent.
So this means (aside from the other known health risks) your two joints a day are better than smoking 20 cigarettes a day. But it is definitely not as safe as zero.