Think again. A study from JAMA Psychiatry discovered that marijuana use over a period of time resulted in a higher chance of periodontal disease. This occurs when the gums become infected or inflamed.
However, the study did also find that marijuana users also brush their teeth less often than non-users so that can contribute to periodontal disease. Legality aside, do keep in mind what regular smoking can do to your dental health and the importance of good dental practices to help negate any bad habits.