With the legalization of marijuana in recent years across the nation for medicinal use, questions concerning its oral effects have raised concern in the dental community. As with any drug, prescription or not, side effects can be seen in the oral cavity and have lasting implications.

Immediate effects include dry mouth and throat. While these symptoms decrease as the drugs effect wear off in the beginning, long term users can expect dry mouth (xerostomia) to become a chronic problem. Xerostomia increases ones risk to periodontal disease which can lead to premature loss of teeth. It can also increase the risk of developing dental decay.

The main psychoactive ingredient to marijuana is THC which provides the high or euphoric feeling. THC has been shown to interfere with the transfer of calcium within the body which is vital in keeping teeth healthy and strong. Chronic users can expect their teeth to become more susceptible to decay not only due to xerostomia, but due to problems with calcium exchange as well.

As with cigarettes, long term users are at an increased risk for mouth cancer. In fact, marijuana has been shown to have a higher concentration of cancer causing ingredients. Furthermore, marijuana smokers have been shown to hold the smoke longer in the mouth and lungs than the typical tobacco smoker increasing exposure to these cancer causing agents.

Obstructed airways, increased phlegm production, negative effects to the immune system and an increase in oral yeast infection (candidiasis) are side effects as well.

While marijuana has been shown to improve quality of life for those suffering from cancer, HIV infection, glaucoma and many other diseases, its long term effects to the oral cavity should be evaluated prior to incorporation of the drug in ones treatment. Recreational users should be especially critical and make an informed decision in the use of marijuana.