The clinical implications of cannabis use in dentistry

Cannabis is the most commonly used illicit drug in the United Kingdom, with recent public health statistics indicating a steady rise in its recreational use.1 Recreational cannabis is known commonly as marijuana, weed, grass, or hash.

There are many strains of marijuana and multiple methods of ingestion. The most well-known method is with hand-rolled cigarettes called joints or hollowed out cigars called blunts. Blunts are considered to be more potent because of the additional effects of the tobacco, causing a more immediate reaction.2 Marijuana can also be smoked in pipes, water pipes (bongs), or cigars. Marijuana or hash prepared as food or drinks, called edibles, are also increasing in popularity. CBD (cannabidiol) is one of several compounds found in the cannabis plant. CBD is legal in the UK (as long as it contains less than 1 mg of THC or THCV or CBN) and patients may be using it for medicinal benefits (it does not produce a ‘high’) by placing the CBD oil sublingually.

Dental professionals are increasingly likely to encounter patients who disclose recreational cannabis use. This article examines the impact of recreational cannabis on oral and general health, outlines appropriate dental management strategies, and summarises the legal framework surrounding cannabis in the UK. The aim is to provide practical, evidence-based guidance that enhances patient care and interprofessional collaboration.

In the UK, cannabis is classified as a Class B drug under the Misuse of Drugs Act 1971.3 Despite this legal status, the 2021 UK census indicated there are 2.5 million users with 16.5% of the 16-24 age group reporting usage.1 The public health implications extend beyond substance misuse, as cannabis use has been associated with a range of oral and systemic health concerns. While medicinal cannabis has gained limited approval for specific conditions under strict regulation, recreational use remains illegal in the UK.4

Cannabis use has been linked to several adverse oral health outcomes. Studies suggest that cannabis can reduce salivary flow, leading to xerostomia (dry mouth), and reduced saliva buffering capacity, which in turn increases the risk of dental caries and periodontal disease.5,6,7 Furthermore, chronic cannabis use has been associated with an increased prevalence of gingival inflammation and plaque accumulation.7 Additionally, THC (tetrahydrocannabinol), the main psychotropic agent in cannabis, is an appetite stimulant, causing users to frequently consume cariogenic foods. Other oral conditions associated with cannabis include chronic inflammation of the oral cavity, leukoplakia and the immunosuppressive effects of cannabis may contribute to the higher prevalence of oral candidiasis.8 There is emerging evidence of links to several malignancies including oral cancer.9

Oral healthcare professionals should be alert to signs such as dry mucosa, heightened plaque levels and unexplained periodontal deterioration in patients who disclose regular cannabis use. A careful clinical examination, complemented by a detailed patient history, is essential to differentiate cannabis-related changes from other aetiologies. Moreover, any patient who attends a dental appointment suspected to be under the influence of cannabis has a diminished ability to consent. The oral healthcare professional responsible for treating such patients should consider refusing to treat a cannabis-intoxicated (‘high’) patient.8

Beyond oral health, cannabis use can impact general health in ways that are relevant to dental care. Cannabis has been linked to cardiovascular effects, such as tachycardia and, in some cases, arrhythmias, which may complicate dental procedures that involve stress or the use of local anaesthetic with vasoconstrictors.8,10 Additionally, the psychoactive effects of cannabis can influence patient cooperation and anxiety levels during dental treatment. It is crucial for clinicians to recognise potential drug interactions (such as with opioids and sedatives).11,12

Moreover, regular cannabis use may affect cognitive function and decision-making, potentially influencing a patient’s adherence to oral hygiene practices and appointment attendance.13 Oral healthcare professionals should consider these factors when developing personalised preventive care plans.

When a patient discloses cannabis use, oral healthcare professionals should adopt a non-judgemental, supportive approach. Clinicians should ask open-ended questions to understand the frequency, duration, and method of use. For instance:

‘Can you tell me about your cannabis use and how often you use it?’

‘Have you noticed any changes in your oral health, such as dry mouth, toothache or tooth and/or gum sensitivity?’

These questions provide information for risk/susceptibility assessment but also encourage honest dialogue. It is important to integrate these inquiries into the broader context of a comprehensive medical and social history. A diet diary may also be useful to understand irregular snacking habits.5

Oral healthcare professionals should advise patients on the potential oral health risks associated with cannabis use. Recommendations include:5,8,14

Enhanced oral hygiene: emphasise the importance of regular brushing, flossing and the use of fluoride toothpaste to counteract the increased risk of caries and periodontal disease

Hydration: encourage patients to maintain adequate and appropriate hydration (with plain water) to mitigate xerostomia

Regular dental visits: reduce recall intervals for dental consultations for active surveillance of any emerging issues related to cannabis use

Lifestyle modification: provide or signpost support for reducing or ceasing cannabis use, where appropriate

The discussion should be framed within a context of patient-centred care, ensuring that the advice is both informative and supportive.

In the UK, several support services are available to assist patients with substance misuse, including cannabis. The NHS offers specialised drug and alcohol services that provide counselling, support groups and, in some cases, pharmacological interventions. Oral healthcare professionals can refer patients to local Drug and Alcohol Recovery Services (DARS) for further assistance. Cannabis users’ general medical practitioners can refer patients to specialist services.15 Additionally, Talk To Frank16 can provide advice and signpost users to their nearest drug and alcohol support groups. Clinicians should be familiar with local referral pathways and support networks to ensure that patients receive comprehensive care that addresses both their dental and general health needs.

Under current UK legislation, recreational cannabis use is illegal, and possession can lead to criminal charges.3 However, the role of the oral healthcare professional is not to enforce legal sanctions but to provide safe, effective, and non-judgemental care.

Oral healthcare professionals should:

Document disclosures: maintain accurate and confidential records of any patient disclosures related to cannabis use

Advise on legal implications: inform patients, where appropriate, about the legal status of cannabis and the potential risks associated with its use

Professional boundaries: reassure patients that the primary focus is on their health and wellbeing

Interprofessional collaboration: work alongside medical colleagues and support services to provide a holistic approach to care.

Cannabis use presents multifaceted challenges in dental practice, influencing both oral and general health. Oral healthcare professionals must be equipped to recognise the signs of cannabis-related oral health issues and engage in empathetic and effective patient communication.

Through a comprehensive approach that integrates enhanced clinical vigilance, supportive patient education and appropriate referral to specialised services, oral healthcare professionals can contribute to the overall health and wellbeing of their patients.