Unless you live under a rock, you know that marijuana is now legal in Colorado for medical or recreational purposes.  The effects of pot have been documented scientifically and empirically.  Drowsiness, increased hunger, mental and physical impairment and a sense of amotivation/apathy are the common negative connotations.  On the medical side, there have been many reported benefits either from smoking it, eating, or using the oil from the cannabinoids.

But from an oral health standpoint, where does it rank,compared to cigarette, cigar smoking, or smokeless tobacco?  Smoking marijuana has a much higher combustion temperature compared to tobacco, and because the goal is to hold it in the lungs for as long as possible, it is capable of inflicting much more heat damage to the oral and fine pulmonary alveolar tissues.   A water bong, hookah, or vaporizer helps cool it and also filters out the impurities for a better high.

Bottom line:  So while the quantity of marijuana being ingested into the lungs is less than tobacco, the mode of delivery can prove to be more dangerous to the oral cavity.