Is there actually a beneficial link between cannabis (aka marijuana) and oral health? It’s no secret that smoke inhalation is a toxic substance that damages tissue in the oral cavity and lungs. People who smoke cannabis consistently are exposed to multiple oral manifestations such as xerostomia, gingivitis and oral mucosal disease. But some recent studies suggest that cannabis may help to reduce oral pain and pulp cavity inflammation, and increase bone density in periapical lesions.
The active components of cannabis are cannabinoids THC and CBD. THC is the psychoactive component while CBD has many medicinal benefits. These cannabinoids act exactly the same as the endogenous endocannabinoids that synthesized in the human body. The endogenous endocannabinoids are called Anandamide and 2-Arachydonoylglycerol (2-AG). The cannabinoids from cannabis and the endogenous cannabinoids stimulate the same system of receptors in the human body which are involved in many physiological processes such as pain modulation, inflammation, bone fracture healing, and appetite. The primary receptors of this endogenous system are CB-1 receptors and CB-2 receptors. These G-protein-coupled receptors are distributed among the nervous system (CB-1) and visceral organs (CB-2), including the dental pulp.
A study from the Dental Institute at King’s College in London sought to evaluate the role of CB-1 receptors in modulating dental pain. The study used 19 patients that were receiving a molar extraction. The subjects were broken into two groups, one group that reported dental pain and another that didn’t report dental pain. With the use of immunohistochemistry and computer imaging analysis, the researchers were able to evaluate CB-1 positive nerve fibers in tooth pulp. CB-1 positive nerve fibers were found scattered in tooth pulp. The study found that CB-1 receptor expression is maintained by nerve fibers in painful human dental pulp. As a result of the findings, CB-1 agonist drugs, including cannabis drugs in pill form that contain THC, may be an alternative choice in dealing with dental pain.
Another study that was conducted by the University of Washington assessed the role of CB-2 receptors in dental pulp exposure-induced periapical bone loss and mandibular bone density. Pulp exposure was created in two separate mice on the mandibular first molars. One mouse had CB-2 receptors intact while the other mouse had CB-2 receptors removed. The pulps remained exposed to the oral cavity, forming a periapical lesion, and the mandibles were harvested for 26 days after the pulp was exposed. The mouse with the intact CB-2 receptors had increased bone density in the mesial root of the pulp than the mouse without CB-2 receptors. The researchers observed that CB-2 mouse had a smaller periapical lesion size than the other mouse, indicating CB-2 receptor’s role in one metabolism. Therefore, the active components in cannabis may stimulate pulp CB-2 receptors and increase bone healing in the oral cavity.