Cannabis (marijuana) is widely used and abused throughout the world. It is the third most popular abused substance, following tobacco and alcohol.1 The Center for Disease Control and Prevention (CDC) estimated that approximately 48.2 million Americans, 18% of the US population, used marijuana at least once in 2019.2 It has further been estimated that approximately 3 in 10 people in the US using marijuana have developed a Cannabis (marijuana) Use Disorder (CUD).3
These statistics are alarming and can impact dental implant treatment provided by clinicians. Acute and chronic marijuana use can affect the success and safety of the conscious or deeply sedated patients. Chronic use will impact the long-term quality of bone supporting dental implants. The bottom line is marijuana use can make life difficult for the dental implant clinician and patients.
Marijuana is retrieved from the hemp plant, Cannabis sativa that contains cannabinoids. The cannabinoid Δ-9-tetrahydrocannabinol (THC) is the principle psychoactive agent. There are numerous preparations of marijuana which vary widely in their THC content. The psychoactive components are dependent upon the variety and/or portion of the plant used and the environment in which the plant is grown. Another type of cannabinoid is Cannabidiol (CBD) oil which does not create the “high” effect or intoxication.4
This Editorial will be presented in two parts. Part 1 presents peri-operative concerns clinicians should consider when treating the cannabis user. Part 2 will focus on the long-term effects marijuana use can have on dental implant success.
Ten known facts regarding marijuana that can affect peri-operative success include4–13:
Tolerance to the effects of cannabis develop quickly, but tolerance also disappears quickly.
Evidence supports a connection between the use of cannabis and the development of Substance Abuse Disorders (SUDs) that include the abuse of alcohol, tobacco, and other illicit drugs. Evidence also suggests that males who smoke cigarettes are at greater risk for the progression of cannabis use to ‘‘problem'' cannabis use.
Short-term effects observed with acute intoxication include enhanced sensory perceptions with euphoria followed by drowsiness/relaxation, slowed reaction time, problems with balance and coordination, increased appetite, problems with learning and memory, hallucinations, anxiety, panic attacks, psychosis, abnormal blood pressure and heart rate (dose dependent), and an increased risk of cardiac arrhythmias and myocardial infarction.
Long-term effects seen with chronic intoxication include mental health problems, chronic cough, frequent respiratory infections, orthostatic hypotension, and predisposition to ischemic heart disease.
Abrupt discontinuation of marijuana results in withdrawal symptoms that include anxiety, restlessness, irritability, depressed mood, mild agitation, insomnia, decreased appetite or weight loss, nausea, and cramping.
Withdrawal symptoms tend to only appear for daily users who suddenly stop using it. Onset of withdrawal symptoms generally occurs within one to two days after cessation of use.
Withdrawal symptoms classically peak within one week and dissipate within two to four weeks.
Marijuana DOES NOT affect respiratory rate, blood glucose concentrations, or pupillary diameter.
There are dose-related drug interactions between cannabis metabolites and the epinephrine contained within dental local anesthetic agents.
Marijuana smoke interferes with soft tissue healing.
These 10 characteristics, plus others, can impact clinical dental implant practices. If a chronic user of marijuana is to undergo an implant procedure the advice provided to the patient on peri-operative use is important.
Preoperative assessment and planning recommendations include:
Screening of patients preoperatively to ascertain cannabis utilization prior to surgery.
Assessing daily cannabis intake and the duration of cannabis use.
Identifying the method of cannabis consumption.
For patients consuming cannabis more than once per day, it is appropriate to screen for cannabis use disorder (CUD).
When planning anesthesia for patients consuming cannabis, thought should be given to the use of local anesthesia as the sole anesthetic to be used and omitting sedation techniques.
On the day of surgery, it is essential to record the time cannabis was last consumed.14
Traditionally, it has been thought that all cannabis products, regardless of dose, should be discontinued 10-days prior to a surgical procedure. While this succinct guidance is easy to adopt into clinical practice, this advice maybe an oversimplification of a nuanced clinical issue and is potentially harmful to patients. Davidson et al. suggest that “based on the current literature and clinical experience, it is clear that a blanket statement suggesting preoperative cessation of cannabis is currently not justified and is potentially dangerous.”15
Considerations for cannabis consumption weaning are:
When there are more than 7 days prior to surgery, cannabis tapering, or cessation may be an option if the patient is consuming more than:
1.5 grams/day of smoked cannabis (on average 1 joint is 0.32 grams)
300 mg/day CBD oil,
20 mg/day THC oil
When a patient consumes cannabis products more than two to three times/day with an unknown CBD or THC content, consideration should also be given to weaning. An example being: for a patient consuming 2 g/day of inhaled cannabis, weaning to 1.5 g/day is a sensible target to be achieved 7 days prior to the surgery. When a patient is motivated to reduce consumption, then preoperative weaning to lower doses or cessation should be considered.
However, when there are less than 7 days prior to surgery and the daily dose of cannabis exceeds the doses listed in bullets 1 & 2 above, consideration of weaning or reevaluation of weaning recommendations are necessary. In these circumstances, the implant dentist should engage in consultation(s) with pain medicine, addiction medicine, or psychiatry specialist before undertaking the surgery.
Marijuana use is becoming more common place with its legalization. The Implant Dentist must be aware of the possible peri-operative effects on treating the patient who is a frequent or recent user of marijuana. A subsequent Editorial will address the short- and long-term effects of acute and chronic marijuana use on dental implant success.
