Dentistry in the New World of CBD
The substance may show promise, but more research needs to be performed.
This is a Self-Instruction article worth 1 CE credit.
CBD (cannabidiol) is a component of the cannabis plant that can help relieve pain without the euphoric, psychoactive effects of tetrahydrocannabinol (THC), another component of cannabis.1 Cannabis plant varieties with THC levels not exceeding a 0.3% concentration on a dry-weight basis are classified as “hemp,” which can legally be used for a variety of purposes, including fabric, cosmetics, food products and CBD production; cannabis varieties with THC concentrations in excess of 0.3% are classified as “marijuana” and are regulated by the Drug Enforcement Administration (DEA) as Schedule 1 controlled substances.2
According to the U.S. Department of Agriculture (USDA), prior to the Agricultural Improvement Act of 2018 (2018 Farm Bill), all varieties of cannabis were subject to the Controlled Substance Act (CSA) — which is enforced by the DEA — and only growers registered under the CSA could produce hemp. However, the 2018 Farm Bill removed hemp from the list of Schedule 1 substances and mandated that the USDA establish a program to approve regulatory plans submitted by states and tribal entities for the production of hemp, as well as to oversee hemp production in states and tribal entities that do not have a USDA-approved plan.2,3 The 2018 Farm Bill created a legal pathway for hemp-derived products such as CBD as long as the hemp contains 0.3% THC or less, is grown in compliance with associated federal and state regulations, and is harvested by a licensed grower, according to John Hudak, deputy director of the Brookings Institution Center for Effective Public Management. “All other cannabinoids produced in any other setting remain a Schedule I substance under federal law and are thus illegal,” wrote Hudak in an article on the Brookings Institution’s blog, meaning CBD produced from cannabis classified as marijuana remains a controlled substance, though many states have legalized marijuana production.4 With the changes to federal law, it is now possible to legally obtain hemp-derived CBD throughout the United States, and marijuana-derived CBD is available in states that have legalized it in contradiction to federal law.
Also in 2018, the U.S. Food and Drug Administration (FDA) approved Epidiolex®, an oral solution for the treatment of seizures for patients with two rare and severe forms of epilepsy. The active ingredient is CBD, making it the first FDA-approved drug with a substance derived from cannabis.5
Is there potential for future applications of CBD in dentistry?
A Complicated Legal and Medical Picture
Despite being removed from the list of controlled substances, hemp-derived CBD is still subject to FDA regulation, and the FDA only endorses CBD products that have been approved through its drug approval process, which, so far, only includes Epidiolex.3 The legalization of hemp-derived CBD nationwide and of marijuana production in several states has paved the way for a growing industry, and BDS Analytics forecasts the industry will grow from $1.9 billion in 2018 to $20 billion in 2024. The company also reported that CBD sales in dispensaries have increased at a faster rate than overall dispensary sales since 2014.6
The already wide range of CBD products is expanding, from ingestibles like chewable capsules, gummies, coffee and tea to topicals like ointments, creams and balms.6 Even pet products are being introduced, although the FDA cautions that concerns about unproven medical claims and the unknown quality of non-FDA-approved products apply to CBD products for both humans and pets.3
Companies are also releasing products like chewing gum and toothpaste and are researching more potential dental applications. “CBD has shown great potential for therapeutic use in dentistry,” said Mary Borstelmann, a media relations specialist for AXIM Biotechnologies Inc., a company that researches and develops CBD-based pharmaceutical products. “As CBD continues to be accepted across the globe and more in-depth research is conducted on its specific capabilities in dentistry, I do see the role of CBD in dentistry expanding to utilize its potent antibacterial properties.”
Government officials and many medical practitioners are not as confident of the benefits and see the science as lagging behind the market. In early 2019, an FDA spokesperson said, “This deceptive marketing of unproven treatments raises significant public health concerns, as it may keep some patients from accessing appropriate, recognized therapies to treat serious and even fatal diseases.”7
The rush to label CBD as a magic pill for a variety of ailments may lead to serious unintended consequences, according to some experts. “At this time, there is not a role for CBD in dentistry,” said Mark Donaldson, PharmD, FASHP, FACHE, associate principal, pharmacy advisory solutions, at Vizient. “Drug interactions are probably the main concern, but many of these products are not standardized with regard to a patient’s dose, duration of exposure, indications for use and even purity.”
The federal government is funding research into medical uses of cannabis, and physicians and dentists may soon have a better understanding of CBD’s uses and interactions.8
Growing Acceptance of Marijuana
The number of states that have legalized marijuana has continued to increase since the mid-1990s when California became the first state to legalize medical marijuana.9 More than half of the states and the District of Columbia now allow medical marijuana, and 11 states and the District of Columbia have fully legalized marijuana.10 Usage rates have also gone up — according to the 2019 World Drug Report published by the United Nations (UN), the number of people who had used marijuana at least once in the past year increased 60% between 2007 and 2017, and the number of daily or near daily users more than doubled in the same period. In Colorado, which was one of the first states to legalize recreational marijuana, the potency of both the cannabis flower and its concentrates increased about 20% from 2014 to 2017, and there has been a fivefold increase in the portion of cannabis concentrates tested that contained more than 75% THC in recent years.11
The UN also found that heavy users accounted for the vast majority of consumers of cannabis products in the market, despite representing only a small population of all cannabis users. Further, the UN stated that “the scientific literature suggests that people using cannabis who progress to daily use have a higher probability of developing cannabis use disorders, while regular and heavy use of cannabis with a high THC content has been identified as a risk factor for acute and chronic adverse health outcomes.” Additionally, the UN found that in locales where high THC–content cannabis has been available, more individuals sought treatment for cannabis use disorders.11
From increasing tax revenues to safer mechanisms to deliver the popular drug to the reduction of marijuana arrests, legalization has offered significant benefits to states. There has also been an observed increase in negative health outcomes. For instance, the Colorado Department of Public Safety (CDPS) found that marijuana-related hospitalization rates in Colorado increased from 575 per 100,000 prior to the legalization of medical marijuana to 803 per 100,000 during the period when medical marijuana was legalized but not yet commercialized (2001–2009), and the rate increased significantly to 1,440 per 100,000 after medical marijuana was commercialized (2010–2013). CDPS also found an increase in marijuana usage among 18- to 25-year-olds, with the rate rising from 21% in 2005–2006, prior to the commercialization of medical marijuana, to 32% in 2015–2016 after the legalization and commercialization of recreational marijuana. The CDPS states that rising usage rates and hospitalizations due to the drug could also be the result of “decreased stigma and legal consequences associated with use rather than actual changes in use patterns.”12
Research into Cannabis
In the United States today, the number of individuals registered by the DEA to conduct medical and scientific research on marijuana and its extracts and derivatives, including THC, has “increased by more than 40 percent from 384 in January 2017 to 542 in January 2019,” according to the DEA. “Similarly, in the last two years, DEA has more than doubled the production quota for marijuana each year based on increased usage projections for federally approved research projects.”13
The growing wave of research could open new doors to medicinal uses and understanding the components of cannabis. In September 2019, the National Institutes of Health announced the award of nine research grants totaling $3 million to researchers investigating cannabis’ capacity to relieve pain and the mechanisms behind the more than 110 cannabinoids and 120 terpenes in cannabis. The studies will look into how cannabis can be used as an anti-inflammatory and an analgesic, which could have profound relevance to dentistry.8
“The treatment of chronic pain has relied heavily on opioids, despite their potential for addiction and overdose and the fact that they often don’t work well when used on a long-term basis,” said Helene Langevin, MD, director of the National Center for Complementary and Integrative Health (NCCIH) in a September press release. “There’s an urgent need for more effective and safer options.”8
While research into potential medical uses of CBD is growing, its applications are in their infancy. In early 2020, a team of researchers will begin testing whether CBD can be used to alleviate symptoms of psychosis in patients with Parkinson’s. If successful, CBD could in some instances replace current antipsychotics that, through their method of action, compound the movement problems these patients have by worsening their motor skills.14
In a 2017 study, researchers investigated how CBD could treat the pain associated with osteoarthritis (OA). The authors wrote that there are limited options to deal with this chronic pain, and evidence shows patients may experience multiple types of pain, such as nociceptive, nociceptive inflammatory and neuropathic. The study concluded that “CBD administration inhibited pain and peripheral sensitization in established OA” and that “CBD may be a safe therapeutic to treat OA pain locally as well as block the acute inflammatory flares that drive disease progression and joint neuropathy.”1
“Research has demonstrated that CBD is safe to use and possesses antioxidant, anti-inflammatory and analgesic properties, but more studies are definitely needed before recommending this as a possible treatment,” said Donaldson.15
The Impact on Dentistry
As both hemp- and marijuana-derived cannabis products like CBD become more widely accepted, dentists face a predicament. The increasing likelihood of seeing patients who use these products could mean dental practices will have more cannabis-related dental health problems, health problems associated with counterfeit CBD products as well as potential negative interactions with medicines used during procedures. “If possible, dentists should always exercise caution and make it a point to not treat active users,” Donaldson said. For example, a practice could adopt the policy that patients who use cannabis and cannabis-related products will not be treated if they use these products on the day of treatment.
In a 2016 article in General Dentistry, Moshe M. Rechthand, DDS, and Nasir Bashirelahi, PhD, PharmD, wrote that marijuana smokers see a higher rate of dental problems, including tooth decay and missing teeth, along with increased plaque and greater severity of gingivitis than non-drug users. They also cautioned that marijuana smokers experience xerostomia even more frequently than tobacco smokers, and this creates conditions that increase the likelihood of periodontal disease and caries.16 Marijuana can also act as an immunosuppressant and increase the prevalence of fungal infection and density in colonies, according to the ADA, and “smoking marijuana is associated with gingival enlargement, erythroplakia, and chronic inflammation of the oral mucosa with hyperkeratosis and leukoplakia.”17
Some of these negative effects may only appear when smoking cannabis, according to Donaldson, but more research must be conducted to understand how and why cannabis causes oral health problems before products like CBD oil can be considered safe.
Marijuana can trigger tachycardia and even acute myocardial infarction — during an appointment, local anesthetics with epinephrine could lead to serious consequences for patients actively using marijuana, while patients under the influence could have acute anxiety, dysphoria and paranoiac thoughts from a regular visit to the dentist, according to Rechthand and Bashirelahi. The authors wrote that “it is incumbent on dental health professionals to be fully prepared and well versed in marijuana’s effects on the body, both positive and negative.”16
Known and unknown drug interactions must be of prime concern, according to Donaldson. “For patients who smoke marijuana, we now need to consider that the psychoactive cannabinoid THC is in play, so we do not want to add medications that could compound these effects, like benzodiazepines or opioids,” he said. “If additional anti-anxiety medication is needed, nitrous oxide would be the safest medication to use. But the possibility of other drug interactions is a concern and is unpredictable given the different types, doses and durations of exposure to marijuana.”
Current Studies on the Applications of CBD in Dentistry
A recent literature review evaluated both the etiopathogenesis of oral mucositis and the methods of action of CBD to evaluate whether CBD should be investigated as a source of prevention and treatment of oral mucositis, specifically when caused by the oxidative stress induced by radiation and chemotherapy. The review concluded that the antioxidant, anti-inflammatory and analgesic properties of CBD could be compatible treatments for oral mucositis and that studies testing CBD as treatment for oral mucositis and other “difficult-to-manage” oral diseases should be encouraged.15
While THC has anxiogenic effects and can trigger anxiety, CBD has anxiolytic effects, and a recent study determined that there is potential for CBD to counter symptoms from a variety of anxiety disorders in short-term applications. “We found that existing preclinical evidence strongly supports CBD as a treatment for generalized anxiety disorder, panic disorder, social anxiety disorder, obsessive-compulsive disorder and post-traumatic stress disorder when administered acutely,” wrote Esther M. Blessing, MD, PhD, and a team of researchers in the journal Neurotherapeutics.18 This potential for treating acute anxiety could prove useful for treating dental anxiety, though this application has yet to be studied.
Treating dental pain is another area where CBD could be applicable, but more research is needed both on its efficacy and the interactions it has with other drugs, according to Peter Grinspoon, MD, an instructor at the Harvard Medical School. “Without sufficient high-quality evidence in human studies, we can’t pinpoint effective doses, and because CBD is currently mostly available as an unregulated supplement, it’s difficult to know exactly what you are getting,” wrote Grinspoon in a 2018 post for the Harvard Health Blog.19
Vaping and Fake CBD
Vape pens and e-cigarettes are battery-powered devices that heat liquid to produce an inhalable aerosol, which can contain nicotine, THC, CBD, flavorings and a variety of other products. Studies that assess the impact on oral health of vaping CBD and THC specifically are unavailable, but a 2019 study examined the impact of vaping nicotine. In it, researchers examined the final results of more than 18,000 participants who used e-cigarettes with nicotine. Those who used nicotine vaping products experienced a higher likelihood of periodontal disease and bone loss around teeth, and participants who also had a history of marijuana use had slightly higher odds.20
The prevalence of CBD vaping products is an overall health concern because it often exists in a dangerous and unregulated market. People who believe they are inhaling CBD may actually be taking counterfeit versions of cannabis or other powerful street drugs. Of the 30 vaping products the Associated Press surveyed in September 2019, 10 contained no CBD despite their claims.21 In an additional study, law enforcement across the United States submitted 350 samples, and 128 of them contained synthetic CBD, even though the products were advertised as containing real CBD.21 As the DEA has turned its focus to the opioid crisis, synthetic CBD has worked its way into the market at a fraction of the cost of real CBD.21
Further, the U.S. Army released a warning about CBD vape products in 2018, as patients exhibited symptoms ranging from “headache, nausea, vomiting, palpitations, dilated pupils and dizziness to confusion, disorientation, agitation and seizures, all of which are consistent with synthetic cannabinoids.”22 Officials in North Carolina witnessed more than 30 residents check into the ER with “altered mental states, hallucinations, seizures, loss of consciousness and rapid heartbeats” after vaping CBD.23 While these cases may be tied to strains of fake CBD, there is also potential for long-term adverse health impacts unique to e-cigarette devices themselves. A 2018 study found that, due to transfer from the heated coils used to generate the aerosol to the liquid and resulting aerosol, “e-cigarettes are a relevant source of exposure to a wide variety of toxic metals including [chromium], [nickel] and [lead] as well as to essential metals that are potentially toxic through inhalation such as [manganese] and [zinc].” The researchers went on to state that additional research is needed to quantify potential metal toxicity from chronic inhalation of e-cigarette aerosols and implications for human health.24
Safety and Side Effects of CBD
In his Harvard Health Blog post, Grinspoon noted that CBD is sold as a supplement, not as a medication, and that the FDA does not regulate the safety or purity of supplements, “so you cannot know for sure that the product you buy has active ingredients at the dose listed on the label. In addition, the product may contain other (unknown) elements.” He stated that possible known side effects include nausea, fatigue and irritability, along with raising the levels of certain other medications in your bloodstream, such as the blood thinner warfarin, through a mechanism similar to that of grapefruit juice. “We also don’t know the most effective therapeutic dose of CBD for any particular medical condition,” Grinspoon wrote.19
While an increasingly large body of research is underway to study these effects and find areas in which CBD can be used, dentists do not yet have the results to help them in the clinic. Aside from anecdotal evidence, it is currently unknown what the most effective CBD dose would be to help ease dental anxiety or pain, as well as what potential side effects and drug interactions could occur. As restrictions are eased and cannabis products become more prevalent, dental patients are potentially using more of these products more frequently. They may also be ingesting counterfeit product.
If patients are using CBD products, “dentists should exercise caution and use conservative doses of medications they currently utilize, as drug interactions with CBD can be hard to predict,” Donaldson said.
Dan Kolen is a freelance writer and media producer based in Chicago. To comment on this article, email impact@agd.org.
References
1. Philpott, Holly T., et al. “Attenuation of Early Phase Inflammation by Cannabidiol Prevents Pain and Nerve Damage in Rat Osteoarthritis.” The Journal of Pain, vol. 158, no. 12, Dec. 2017, pp 2442-2451.
2. Agricultural Marketing Service; USDA. “Establishment of a Domestic Hemp Production Program. Federal Register: The Daily Journal of the United States Government, 31 Oct. 2019, www.federalregister. gov/documents/2019/10/31/2019-23749/establishment-of-a-domestic-hemp-production-program. Accessed 16 Dec. 2019.
3. U.S. Food & Drug Administration. “What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD.” FDA Consumer Updates, 25 Nov. 2019, www.fda.gov/consumers/consumer-updates/what-you-need-know-and-what-were-working-find-out-about-products-containing-cannabis-or-cannabis. Accessed 16 Dec. 2019.
4. Hudak, John. “The Farm Bill, Hemp Legalization and the Status of CBD: An Explainer.” The Brookings Institute, 14 Dec. 2018, www.brookings.edu/ blog/fixgov/2018/12/14/the-farm-bill-hemp-and-cbd-explainer/. Accessed 16 Dec. 2019.
5. U.S. Food & Drug Administration. “FDA Approves First Drug Comprised of an Active Ingredient Derived from Marijuana to Treat Rare, Severe Forms of Epilepsy.” FDA Newsroom, 25 June 2018, www.fda.gov/news-events/press-announcements/fda-approves-first-drug-comprised-active-ingredient-derived-marijuana-treat-rare-severe-forms. Accessed 16 Dec. 2019.
6. BDS Analytics. “U.S. CBD Market Anticipated to Reach $20 Billion in Sales by 2024.” BDS Analytics, 9 May 2019, www.bdsanalytics.com/u-s-cbd-market-anticipated-to-reach-20-billion-in-sales-by-2024/. Accessed 16 Dec. 2019.
7. Rabin, Roni Caryn. “CBD Is Everywhere, but Scientists Still Don’t Know Much About It.” The New York Times, 25 Feb. 2019, www.nytimes.com/2019/02/25/well/live/cbd-cannabidiol-marijuana-medical-treatment-therapy.html. Accessed 25 Feb. 2019.
8. National Center for Complementary and Integrative Health. “NIH to Investigate Minor Cannabinoids and Terpenes for Potential Pain-Relieving Properties.” U.S. Department of Health and Human Services, National Institutes of Health, 19 Sept. 2019. www.nccih.nih.gov/news/press/09192019. Accessed 16 Dec. 2019.
9. Balzar, John. “Voters Approve Measure to Use Pot as Medicine.” Los Angeles Times, 6 Nov. 1996, www.latimes. com/archives/la-xpm-1996-11-06-mn-62740-story.html. Accessed 16 Dec. 2019.
10. DISA Global Solutions. “Map of Marijuana Legality by State.” DISA, updated December 2019, www.disa.com/map-of-marijuana-legality-by-state. Accessed 16 Dec. 2019.
11. United Nations Office on Drugs and Crime. “2019 World Drug Report: Executive Summary.” United Nations, June 2019, wdr.unodc.org/wdr2019/prelaunch/WDR19_Booklet_1_EXECUTIVE_SUMMARY.pdf. Accessed 16 Dec. 2019.
12. Colorado Division of Criminal Justice, Office of Research and Statistics. “Impacts of Marijuana Legalization in Colorado: A Report Pursuant to Senate Bill 13-283.” Colorado Department of Public Safety, October 2018, https://cdpsdocs.state.co.us/ors/docs/reports/2018-SB13-283_Rpt.pdf. Accessed 16 Dec. 2019.
13. U.S. Department of Justice, Drug Enforcement Administration. “DEA Announces Steps Necessary to Improve Access to Marijuana Research.” DEA, 26 Aug. 2019, www.dea.gov/press-releases/2019/08/26/dea-announces-steps-necessary-improve-access-marijuana-research. Accessed 16 Dec. 2019.
14. Walter, Kenny. “Investigators Testing CBD as Treatment for Parkinson Disease-Related Psychosis.” MD Magazine, 15 Oct. 2019, www.mdmag.com/medical-news/cbd-parkinson-diseaserelated-psychosis. Accessed 16 Dec. 2019.
15. Cuba, Letícia de Freitas, et al. “Cannabidiol: An Alternative Therapeutic Agent for Oral Mucositis?” Journal of Clinical Pharmacy and Therapeutics, vol. 42, no. 3, June 2017, pp 245-250.
16. Rechthand, Moshe M., and Nasir Bashirelahi. “What Every Dentist Needs to Know About Cannabis.” General Dentistry, vol. 64, no. 1, Jan.-Feb. 2016, pp 40-43.
17. Center for Scientific Information, ADA Science Institute. “Cannabis: Oral Health Effects.” American Dental Association, updated 12 July 2019, www.ada.org/en/member-center/oral-health-topics/cannabis. Accessed 16 Dec. 2019.
18. Blessing, Esther M., et al. “Cannabidiol as a Potential Treatment for Anxiety Disorders.” Neurotherapeutics, vol. 12, no. 4, Oct. 2015, pp. 825-836.
19. Grinspoon, Peter. “Cannabidiol (CBD) — What We Know and What We Don’t.” Harvard Health Blog, 24 Aug. 2018, updated 27 Aug. 2019, www.health.harvard.edu/blog/cannabidiol-cbd-what-we-know-and-what-we-dont-2018082414476. Accessed 16 Dec. 2019.
20. Atuegwu, Nkiruka C., et al. “Association Between Regular Electronic Nicotine Product Use and Self-Reported Periodontal Disease Status: Population Assessment of Tobacco and Health Survey.” International Journal of Environmental Research and Public Health, vol. 16, no. 7, April 2019, p. E1263.
21. Holbrook, Mohr; Associated Press. “The AP Tested 30 Kinds of CBD Vaping Oil: More Than a Third Contained Synthetic Marijuana, or No CBD at All.” Chicago Tribune, 17 Sept. 2019, www.chicagotribune.com/nation-world/ct-nw-vaping-cbd-bad-drugs-20190917-77fx47fb2jey7okmk223drbrlq-story.html. Accessed 16 Dec. 2019.
22. Army Public Health Center. “Health Effects of Vape Oils Containing Unknown Substances.” APHC, 25 April 2018, phc.amedd.army.mil/topics/healthyliving/tfl/Pages/VapeOils.aspx. Accessed 16 Dec. 2019.
23. Henderson, Bruce. “CBD Oil in Your e-Cig or Vape Pen Might Send You to the ER, NC Says.” The Charlotte Observer, 6 March 2018, www.charlotteobserver.com/news/local/article203727924.html. Accessed 16 Dec. 2019.
24. Olmedo, Pablo, et al. “Metal Concentrations in e-Cigarette Liquid and Aerosol Samples: The Contribution of Metallic Coils.” Environmental Health Perspectives, vol. 126, no. 2, Feb. 2018, p. e027010.
This is a Self-Instruction article worth 1 CE credit.
CBD (cannabidiol) is a component of the cannabis plant that can help relieve pain without the euphoric, psychoactive effects of tetrahydrocannabinol (THC), another component of cannabis.1 Cannabis plant varieties with THC levels not exceeding a 0.3% concentration on a dry-weight basis are classified as “hemp,” which can legally be used for a variety of purposes, including fabric, cosmetics, food products and CBD production; cannabis varieties with THC concentrations in excess of 0.3% are classified as “marijuana” and are regulated by the Drug Enforcement Administration (DEA) as Schedule 1 controlled substances.2
According to the U.S. Department of Agriculture (USDA), prior to the Agricultural Improvement Act of 2018 (2018 Farm Bill), all varieties of cannabis were subject to the Controlled Substance Act (CSA) — which is enforced by the DEA — and only growers registered under the CSA could produce hemp. However, the 2018 Farm Bill removed hemp from the list of Schedule 1 substances and mandated that the USDA establish a program to approve regulatory plans submitted by states and tribal entities for the production of hemp, as well as to oversee hemp production in states and tribal entities that do not have a USDA-approved plan.2,3 The 2018 Farm Bill created a legal pathway for hemp-derived products such as CBD as long as the hemp contains 0.3% THC or less, is grown in compliance with associated federal and state regulations, and is harvested by a licensed grower, according to John Hudak, deputy director of the Brookings Institution Center for Effective Public Management. “All other cannabinoids produced in any other setting remain a Schedule I substance under federal law and are thus illegal,” wrote Hudak in an article on the Brookings Institution’s blog, meaning CBD produced from cannabis classified as marijuana remains a controlled substance, though many states have legalized marijuana production.4 With the changes to federal law, it is now possible to legally obtain hemp-derived CBD throughout the United States, and marijuana-derived CBD is available in states that have legalized it in contradiction to federal law.
Also in 2018, the U.S. Food and Drug Administration (FDA) approved Epidiolex®, an oral solution for the treatment of seizures for patients with two rare and severe forms of epilepsy. The active ingredient is CBD, making it the first FDA-approved drug with a substance derived from cannabis.5
Is there potential for future applications of CBD in dentistry?
A Complicated Legal and Medical Picture
Despite being removed from the list of controlled substances, hemp-derived CBD is still subject to FDA regulation, and the FDA only endorses CBD products that have been approved through its drug approval process, which, so far, only includes Epidiolex.3 The legalization of hemp-derived CBD nationwide and of marijuana production in several states has paved the way for a growing industry, and BDS Analytics forecasts the industry will grow from $1.9 billion in 2018 to $20 billion in 2024. The company also reported that CBD sales in dispensaries have increased at a faster rate than overall dispensary sales since 2014.6
The already wide range of CBD products is expanding, from ingestibles like chewable capsules, gummies, coffee and tea to topicals like ointments, creams and balms.6 Even pet products are being introduced, although the FDA cautions that concerns about unproven medical claims and the unknown quality of non-FDA-approved products apply to CBD products for both humans and pets.3
Companies are also releasing products like chewing gum and toothpaste and are researching more potential dental applications. “CBD has shown great potential for therapeutic use in dentistry,” said Mary Borstelmann, a media relations specialist for AXIM Biotechnologies Inc., a company that researches and develops CBD-based pharmaceutical products. “As CBD continues to be accepted across the globe and more in-depth research is conducted on its specific capabilities in dentistry, I do see the role of CBD in dentistry expanding to utilize its potent antibacterial properties.”
Government officials and many medical practitioners are not as confident of the benefits and see the science as lagging behind the market. In early 2019, an FDA spokesperson said, “This deceptive marketing of unproven treatments raises significant public health concerns, as it may keep some patients from accessing appropriate, recognized therapies to treat serious and even fatal diseases.”7
The rush to label CBD as a magic pill for a variety of ailments may lead to serious unintended consequences, according to some experts. “At this time, there is not a role for CBD in dentistry,” said Mark Donaldson, PharmD, FASHP, FACHE, associate principal, pharmacy advisory solutions, at Vizient. “Drug interactions are probably the main concern, but many of these products are not standardized with regard to a patient’s dose, duration of exposure, indications for use and even purity.”
The federal government is funding research into medical uses of cannabis, and physicians and dentists may soon have a better understanding of CBD’s uses and interactions.8
Growing Acceptance of Marijuana
The number of states that have legalized marijuana has continued to increase since the mid-1990s when California became the first state to legalize medical marijuana.9 More than half of the states and the District of Columbia now allow medical marijuana, and 11 states and the District of Columbia have fully legalized marijuana.10 Usage rates have also gone up — according to the 2019 World Drug Report published by the United Nations (UN), the number of people who had used marijuana at least once in the past year increased 60% between 2007 and 2017, and the number of daily or near daily users more than doubled in the same period. In Colorado, which was one of the first states to legalize recreational marijuana, the potency of both the cannabis flower and its concentrates increased about 20% from 2014 to 2017, and there has been a fivefold increase in the portion of cannabis concentrates tested that contained more than 75% THC in recent years.11
The UN also found that heavy users accounted for the vast majority of consumers of cannabis products in the market, despite representing only a small population of all cannabis users. Further, the UN stated that “the scientific literature suggests that people using cannabis who progress to daily use have a higher probability of developing cannabis use disorders, while regular and heavy use of cannabis with a high THC content has been identified as a risk factor for acute and chronic adverse health outcomes.” Additionally, the UN found that in locales where high THC–content cannabis has been available, more individuals sought treatment for cannabis use disorders.11
From increasing tax revenues to safer mechanisms to deliver the popular drug to the reduction of marijuana arrests, legalization has offered significant benefits to states. There has also been an observed increase in negative health outcomes. For instance, the Colorado Department of Public Safety (CDPS) found that marijuana-related hospitalization rates in Colorado increased from 575 per 100,000 prior to the legalization of medical marijuana to 803 per 100,000 during the period when medical marijuana was legalized but not yet commercialized (2001–2009), and the rate increased significantly to 1,440 per 100,000 after medical marijuana was commercialized (2010–2013). CDPS also found an increase in marijuana usage among 18- to 25-year-olds, with the rate rising from 21% in 2005–2006, prior to the commercialization of medical marijuana, to 32% in 2015–2016 after the legalization and commercialization of recreational marijuana. The CDPS states that rising usage rates and hospitalizations due to the drug could also be the result of “decreased stigma and legal consequences associated with use rather than actual changes in use patterns.”12
Research into Cannabis
In the United States today, the number of individuals registered by the DEA to conduct medical and scientific research on marijuana and its extracts and derivatives, including THC, has “increased by more than 40 percent from 384 in January 2017 to 542 in January 2019,” according to the DEA. “Similarly, in the last two years, DEA has more than doubled the production quota for marijuana each year based on increased usage projections for federally approved research projects.”13
The growing wave of research could open new doors to medicinal uses and understanding the components of cannabis. In September 2019, the National Institutes of Health announced the award of nine research grants totaling $3 million to researchers investigating cannabis’ capacity to relieve pain and the mechanisms behind the more than 110 cannabinoids and 120 terpenes in cannabis. The studies will look into how cannabis can be used as an anti-inflammatory and an analgesic, which could have profound relevance to dentistry.8
“The treatment of chronic pain has relied heavily on opioids, despite their potential for addiction and overdose and the fact that they often don’t work well when used on a long-term basis,” said Helene Langevin, MD, director of the National Center for Complementary and Integrative Health (NCCIH) in a September press release. “There’s an urgent need for more effective and safer options.”8
While research into potential medical uses of CBD is growing, its applications are in their infancy. In early 2020, a team of researchers will begin testing whether CBD can be used to alleviate symptoms of psychosis in patients with Parkinson’s. If successful, CBD could in some instances replace current antipsychotics that, through their method of action, compound the movement problems these patients have by worsening their motor skills.14
In a 2017 study, researchers investigated how CBD could treat the pain associated with osteoarthritis (OA). The authors wrote that there are limited options to deal with this chronic pain, and evidence shows patients may experience multiple types of pain, such as nociceptive, nociceptive inflammatory and neuropathic. The study concluded that “CBD administration inhibited pain and peripheral sensitization in established OA” and that “CBD may be a safe therapeutic to treat OA pain locally as well as block the acute inflammatory flares that drive disease progression and joint neuropathy.”1
“Research has demonstrated that CBD is safe to use and possesses antioxidant, anti-inflammatory and analgesic properties, but more studies are definitely needed before recommending this as a possible treatment,” said Donaldson.15
The Impact on Dentistry
As both hemp- and marijuana-derived cannabis products like CBD become more widely accepted, dentists face a predicament. The increasing likelihood of seeing patients who use these products could mean dental practices will have more cannabis-related dental health problems, health problems associated with counterfeit CBD products as well as potential negative interactions with medicines used during procedures. “If possible, dentists should always exercise caution and make it a point to not treat active users,” Donaldson said. For example, a practice could adopt the policy that patients who use cannabis and cannabis-related products will not be treated if they use these products on the day of treatment.
In a 2016 article in General Dentistry, Moshe M. Rechthand, DDS, and Nasir Bashirelahi, PhD, PharmD, wrote that marijuana smokers see a higher rate of dental problems, including tooth decay and missing teeth, along with increased plaque and greater severity of gingivitis than non-drug users. They also cautioned that marijuana smokers experience xerostomia even more frequently than tobacco smokers, and this creates conditions that increase the likelihood of periodontal disease and caries.16 Marijuana can also act as an immunosuppressant and increase the prevalence of fungal infection and density in colonies, according to the ADA, and “smoking marijuana is associated with gingival enlargement, erythroplakia, and chronic inflammation of the oral mucosa with hyperkeratosis and leukoplakia.”17
Some of these negative effects may only appear when smoking cannabis, according to Donaldson, but more research must be conducted to understand how and why cannabis causes oral health problems before products like CBD oil can be considered safe.
Marijuana can trigger tachycardia and even acute myocardial infarction — during an appointment, local anesthetics with epinephrine could lead to serious consequences for patients actively using marijuana, while patients under the influence could have acute anxiety, dysphoria and paranoiac thoughts from a regular visit to the dentist, according to Rechthand and Bashirelahi. The authors wrote that “it is incumbent on dental health professionals to be fully prepared and well versed in marijuana’s effects on the body, both positive and negative.”16
Known and unknown drug interactions must be of prime concern, according to Donaldson. “For patients who smoke marijuana, we now need to consider that the psychoactive cannabinoid THC is in play, so we do not want to add medications that could compound these effects, like benzodiazepines or opioids,” he said. “If additional anti-anxiety medication is needed, nitrous oxide would be the safest medication to use. But the possibility of other drug interactions is a concern and is unpredictable given the different types, doses and durations of exposure to marijuana.”
Current Studies on the Applications of CBD in Dentistry
A recent literature review evaluated both the etiopathogenesis of oral mucositis and the methods of action of CBD to evaluate whether CBD should be investigated as a source of prevention and treatment of oral mucositis, specifically when caused by the oxidative stress induced by radiation and chemotherapy. The review concluded that the antioxidant, anti-inflammatory and analgesic properties of CBD could be compatible treatments for oral mucositis and that studies testing CBD as treatment for oral mucositis and other “difficult-to-manage” oral diseases should be encouraged.15
While THC has anxiogenic effects and can trigger anxiety, CBD has anxiolytic effects, and a recent study determined that there is potential for CBD to counter symptoms from a variety of anxiety disorders in short-term applications. “We found that existing preclinical evidence strongly supports CBD as a treatment for generalized anxiety disorder, panic disorder, social anxiety disorder, obsessive-compulsive disorder and post-traumatic stress disorder when administered acutely,” wrote Esther M. Blessing, MD, PhD, and a team of researchers in the journal Neurotherapeutics.18 This potential for treating acute anxiety could prove useful for treating dental anxiety, though this application has yet to be studied.
Treating dental pain is another area where CBD could be applicable, but more research is needed both on its efficacy and the interactions it has with other drugs, according to Peter Grinspoon, MD, an instructor at the Harvard Medical School. “Without sufficient high-quality evidence in human studies, we can’t pinpoint effective doses, and because CBD is currently mostly available as an unregulated supplement, it’s difficult to know exactly what you are getting,” wrote Grinspoon in a 2018 post for the Harvard Health Blog.19
Vaping and Fake CBD
Vape pens and e-cigarettes are battery-powered devices that heat liquid to produce an inhalable aerosol, which can contain nicotine, THC, CBD, flavorings and a variety of other products. Studies that assess the impact on oral health of vaping CBD and THC specifically are unavailable, but a 2019 study examined the impact of vaping nicotine. In it, researchers examined the final results of more than 18,000 participants who used e-cigarettes with nicotine. Those who used nicotine vaping products experienced a higher likelihood of periodontal disease and bone loss around teeth, and participants who also had a history of marijuana use had slightly higher odds.20
The prevalence of CBD vaping products is an overall health concern because it often exists in a dangerous and unregulated market. People who believe they are inhaling CBD may actually be taking counterfeit versions of cannabis or other powerful street drugs. Of the 30 vaping products the Associated Press surveyed in September 2019, 10 contained no CBD despite their claims.21 In an additional study, law enforcement across the United States submitted 350 samples, and 128 of them contained synthetic CBD, even though the products were advertised as containing real CBD.21 As the DEA has turned its focus to the opioid crisis, synthetic CBD has worked its way into the market at a fraction of the cost of real CBD.21
Further, the U.S. Army released a warning about CBD vape products in 2018, as patients exhibited symptoms ranging from “headache, nausea, vomiting, palpitations, dilated pupils and dizziness to confusion, disorientation, agitation and seizures, all of which are consistent with synthetic cannabinoids.”22 Officials in North Carolina witnessed more than 30 residents check into the ER with “altered mental states, hallucinations, seizures, loss of consciousness and rapid heartbeats” after vaping CBD.23 While these cases may be tied to strains of fake CBD, there is also potential for long-term adverse health impacts unique to e-cigarette devices themselves. A 2018 study found that, due to transfer from the heated coils used to generate the aerosol to the liquid and resulting aerosol, “e-cigarettes are a relevant source of exposure to a wide variety of toxic metals including [chromium], [nickel] and [lead] as well as to essential metals that are potentially toxic through inhalation such as [manganese] and [zinc].” The researchers went on to state that additional research is needed to quantify potential metal toxicity from chronic inhalation of e-cigarette aerosols and implications for human health.24
Safety and Side Effects of CBD
In his Harvard Health Blog post, Grinspoon noted that CBD is sold as a supplement, not as a medication, and that the FDA does not regulate the safety or purity of supplements, “so you cannot know for sure that the product you buy has active ingredients at the dose listed on the label. In addition, the product may contain other (unknown) elements.” He stated that possible known side effects include nausea, fatigue and irritability, along with raising the levels of certain other medications in your bloodstream, such as the blood thinner warfarin, through a mechanism similar to that of grapefruit juice. “We also don’t know the most effective therapeutic dose of CBD for any particular medical condition,” Grinspoon wrote.19
While an increasingly large body of research is underway to study these effects and find areas in which CBD can be used, dentists do not yet have the results to help them in the clinic. Aside from anecdotal evidence, it is currently unknown what the most effective CBD dose would be to help ease dental anxiety or pain, as well as what potential side effects and drug interactions could occur. As restrictions are eased and cannabis products become more prevalent, dental patients are potentially using more of these products more frequently. They may also be ingesting counterfeit product.
If patients are using CBD products, “dentists should exercise caution and use conservative doses of medications they currently utilize, as drug interactions with CBD can be hard to predict,” Donaldson said.
Dan Kolen is a freelance writer and media producer based in Chicago. To comment on this article, email impact@agd.org.
References
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