Sedation Dentistry

There are many people who associate the dental setting with fear and anxiety for completely legitimate reasons. Dentistry is one of the few medical fields where treatment is often rendered without some form of sedation. As is the case, there are times when a traumatic event creates negative memories which invokes anxiety. This creates a vicious cycle of fear that prevents patients from regular visits, leading to more invasive emergency treatment, which then validates those previous fears. One way to ensure regular and proper treatment is to utilize sedation.

What is Sedation Dentistry?

Sedation dentistry is the removal of anxiety prior and during the appointment itself. Sedation makes the patient extremely relaxed and calm, often to the point where they fall asleep. There is a common misconception that patients are being “put to sleep”. However, being put to sleep actually refers to patients being in a state of complete unconsciousness, which is general anesthesia (GA). While there is dentistry that utilizes GA, many people only need moderate sedation. However in order to discuss the nuances of sedation, we must first define the levels of sedation. In the United States, some states will have different definitions and may combine aspects of levels together. It is generally agreed that there are 4 levels of sedation: minimal, moderate, deep and general anesthesia.

Minimal Sedation

This form of sedation minimally depresses the level of consciousness while still producing anxiolysisReduction of anxiety after given a drug.. Patients are able to respond normally to tactile stimulation, verbal commands and are able to hold a conversation normally. Additionally patients are able to independently and continuously maintain their airway and their ventilatory and cardiovascular functions are unaffected. In other words, a person with this level of sedation is able to breathe, speak, and typically comprehends what is happening but still feels relaxed. The patient usually remembers what happens during the visit, however their level of anxiety is very well managed. The most common pharmacological agent used is nitrous oxideAlso known as laughing gas, is the chemical compound N20 that has many uses. In medicine, it is an analgesic and anesthetic. It is paired with oxygen when delivered in a dental setting., also known as laughing gas. Nitrous oxide is a very safe medication and has the major advantage of not needing separate transportation. Patients who only receive nitrous oxide and aren’t pushed to moderate sedation due to concomitant self medication, can drive themselves to and from the dental office. Vitals are monitored, however the equipment required isn’t as extensive as with deeper levels of sedation.

Moderate Sedation

This is the level of sedation that is typically referred to when someone mentions being “knocked out” at a dental procedure. This is an intentional depression of consciousness where patients purposefully respond to verbal commands, prompted by verbal, light tactile stimulation, or a combination of both. Very importantly, no interventions are required to maintain the airway and independent, spontaneous ventilation is present. Typically cardiovascular function is maintained normally. Patients’ vitals are very closely monitored to ensure there is no danger to their health at this and deeper levels of sedation.

While patients are conscious during moderate sedation, the drugs used typically have a powerful amnestic effect resulting in the inability to convert short term to long term memory. In other words, patients are awake and extremely relaxed but have no memory of the appointment. The absence of memory triggers patients to believe they were asleep for the procedure. This level of sedation is perfect for healthy patients who have moderate to severe dental phobia. However there are a few more prerequisites over minimal sedation to be a candidate and this level of sedation requires transportation to and from the dental office.

Deep Sedation

Once a patient has crossed from moderate to deep sedation, the patient is now unconscious. This level of sedation depressed consciousness severely enough in which the patient cannot be easily aroused except through repeated and/or painful stimuli. Another critical difference is patients may not be able to independently maintain their airway and ventilatory function may be imparied as well. If this becomes the case, the patient will require assistance in maintaining their airway. Cardiovascular function, however, is usually maintained. In other words, the patient is unconscious, is completely unaware of what is happening, and may not be able to breathe on their own. 

If a patient is intentionally sedated to this level, the provider is prepared to potentially assist with maintaining the airway and ventilatory functions. To intentionally sedate a patient to this level requires advanced training as well as equipment and support. For dental procedures, this level of sedation does not need to be as in a hospital setting and can happen in a private office with a properly trained provider.

General Anesthesia

The final and deepest level of sedation is used frequently for more invasive treatment and/or with medically compromised patients. The patients are completely unconscious and are not arousable even by painful stimulation. Basic functions are often impaired and require assistance. Patients typically require assistance in airway maintenance and may need positive pressure ventilation due to potential lack of spontaneous ventilation. Cardiovascular function may be impaired as well. 

This is the truest state of a patient being asleep. This level of sedation is required for major surgeries where patients would react to painful stimuli. After all, surgeons would have a difficult time performing open heart surgery if the patient reacted during the procedure. General anesthesia does have a place in dentistry and can be done safely in a dental office.

A very important concept is that sedation is on a continuum, where a patient can seamlessly go between the different levels of sedation. As such, every provider is ready and prepared to treat one level deeper than their intended level of sedation. For instance, all moderate sedation providers are trained and capable of rescuing a patient who unintentionally went beyond moderate sedation. The difference between moderate and deep is the most critical as moderate sedation patients are conscious and require no intervention in maintaining a patent airway or ventilation. Deep and general anesthesia patients are considered unconscious and require limited to complete assistance with airway maintenance and ventilation.

When Would I Need Sedation for Dentistry?

The people who benefit the most from sedation dentistry are those who are extremely afraid or anxious about any dental treatment. Typically, these people have one or a combination of traumatic past experiences, general anxiety, or fear of a medical setting also known as white coat syndrome²https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6233698/. If thinking about routine dental work gives someone extreme anxiety, sedation dentistry may be necessary especially if it causes them to completely avoid regular dental visits. Sedation dentistry is very effective at reducing anxiety and stress associated with dental treatment and can even make you forget you had any treatment.

Whatever the reason(s), these patients tend to stay away from medical providers, including dentists. If this sounds like you, know that there are options to get you comfortable for your dental work.

What are the Most Common Types of Dental Sedation?

There are many combinations of drugs that are used to achieve the desired level of sedation. Commonly used drug classes are: benzodiazepines, opioids, and various types of anesthetics³https://link.springer.com/article/10.2165/00003088-200645090-00001. A good rule of thumb for all treatments in general is to titrate up from the least invasive treatment up to the type that achieves the desired result. In the same way a full joint replacement is not the best treatment option for occasional knee discomfort, general anesthesia is not a good option for someone with mild dental anxiety. 

Depending on the desired effect and level of sedation, different combinations of drugs are used. While there are some drugs that can only be used for a higher level of sedation, there are multiple drugs that can be used in all levels of sedation. We will primarily focus on minimal and moderate sedation.

Nitrous Oxide Sedation 

Nitrous oxide, also known as laughing gas, nitrous, or N20, is a colorless, sweet-tasting gas that has many uses⁶https://pubchem.ncbi.nlm.nih.gov/compound/Nitrous-oxide. In dentistry, is a commonly used inhaled anesthetic due to its effectiveness and huge marginThe interface between a restoration and the tooth. This is the most common area for a cavity to reoccur on a tooth. of safety⁴https://europepmc.org/article/med/7546474⁵https://meridian.allenpress.com/anesthesia-progress/article-abstract/55/4/124/24635/Nitrous-Oxide-and-the-Inhalation-Anesthetics. It produces a euphoric, calming effect and is effective in reducing anxiety with minimal side effects⁷https://adc.bmj.com/content/84/6/492.short. When used as the only drug, the intended depth of sedation is minimal. Nitrous oxide may be used in combination with other drugs when the provider is intending deeper levels of sedation.

Pros

Nitrous oxide is a very safe and effective drug with a very short recovery time. In addition to reducing anxiety and reducing stress, it also has a very fast onset and recovery time. The recovery time is short enough that you can drive to and from your appointment, however check with your state or ask your dentist whether or not a separate driver is required.

It is important to disclose to your provider if you are taking any other medication or supplements. Nitrous oxide administered in conjunction with other medications may induce moderate sedation, thus making it a hazard to drive.

Cons

While there are numerous benefits to nitrous oxide, a major downside is the level of nitrous oxide is that the level of anxiolysis is not enough for many patients. It also does not have any amnestic properties, meaning that the patient is aware and will remember what is happening. For the extremely anxious, deeper levels of sedation may be required.

Oral Conscious Sedation

Oral sedation refers to sedation from taking some type of medication orally, often in the form of a pill. There are many different types of drugs that are administered, each with its own pros and cons. A class of drug that is commonly used are benzodiazepines. They are commonly prescribed for anxiety, insomnia, central nervous system pathology, epilepsy, alcohol withdrawal and muscle relaxation⁸https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684331/⁹https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2019955. Some common drug brand names include Xanax, Ativan, and Valium. While very effective in the short term, benzodiazepines have a high potential for abuse and are regulated by the Drug Enforcement Administration as a class IV drug. 

Pros

Depending on the drug, oral conscious sedation can have a wide variety of effects that last longer and are potentially stronger than nitrous oxide. For instance, benzodiazepines are widely used for the treatment of anxiety and sleep problems⁹https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2019955 and are commonly used as short term anxiety medication in dental offices. They are an effective anxiolytic and some even have amnestic properties as well. Since this type of sedation is taken orally, there is also no need for cannulation, which can be another source of fear and anxiety. However a drug’s route of administration plays a large role in safety and efficacy.

Cons

Due to the types of medications used and route of administration, oral conscious sedation may unintentionally go into deeper levels of sedation. A lack of access to the bloodstream and therefore the brain means reversal agents and emergency medicine will require more time to take effect.
Due to the longer lasting and potentially stronger effects these drugs have, they often require separate transportation to and from the office. Additionally, the length of sedation often requires that the patient be cared for even after safely returning home. Another aspect to keep in mind is the route of administration as previously mentioned. When the same medication is taken orally, the first pass effect comes into play¹⁰https://pubmed.ncbi.nlm.nih.gov/31869143, resulting in an unreliable rate of absorption¹¹https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780209/. When the drug is metabolized prior to reaching the site of action, it reduces the overall effectiveness. Simply put, some of the drug is rendered ineffective before it can even act on the body. Another negative aspect is a degree of unpredictability when waiting for the drug to take effect. For instance there is variability when the stomach empties, which can result in variable amounts of the drug released and absorbed through the gut. This can lead to a drug seemingly not working, causing the provider to administer another dose. If the first and second dose are released by the stomach at the same time, the level of sedation may go deeper than intended.  Also when ingested, there is a longer wait time for the drug to take effect, sometimes 30-60 minutes. Luckily many of these issues can be circumvented with intravenous (IV) sedation.

Moderate Sedation Through the Intravenous Route

Intravenous (IV) sedation uses a parenteral routeAdministration of a drug by bypassing the digestive system. Most often refers to the intravenous route of administration., meaning it bypasses the gastrointestinal tract by gaining access to the bloodstream through a vein. This form of sedation is what most people refer to when they want to be ‘knocked out’ for a dental procedure. The amnestic properties¹³https://link.springer.com/chapter/10.1007/978-3-642-73288-1_11 are why many people cannot remember the procedure and believe they were ‘knocked out’. 

While there are many different drugs used for IV sedation, there are a handful of classes of drugs that are most often used. To achieve the desired depth of sedation, benzodiazepines¹²https://www.sciencedirect.com/science/article/pii/S0007091217378169 and opioids are primarily used but other adjunct medications such as nitrous oxide are also used. Depending on the type of drugs used, the patient may be put into moderate, deep, or general anesthesia via the IV route. 

Pros

There are many significant advantages to IV sedation over oral conscious sedation. The onset of effects are significantly faster; while oral sedation may take 30-60 minutes, the effects from IV sedation can be seen in as little as 15 seconds, sometimes shorter. Additionally the depth of sedation can be titrated to effect, meaning the exact amount of drug can be used. This gives a much higher degree of control and in turn, a higher degree of safety. In the event of an adverse event, the appropriate drugs or reversal medications can be administered and take effect very quickly. This gives the provider the ability to act accordingly and makes the procedure much safer. 

Cons

On the sedation continuumVariable levels of consciousness that seamlessly blend together. The continuum goes from minimal <-> moderate <-> deep <-> general anesthesia. The most important aspect is a patient will be conscious in minimal or moderate but unconscious in deep or general anesthesia. When unconscious, the patient may need help with basic functions such as breathing., the next level after moderate is deep sedation, where patients become unconscious. This means there is an inherent risk of the IV moderate sedation going too deep and may compromise the patient’s ability to maintain normal function of their airway and pulmonary system. However there are ample precautions taken to ensure this does not happen and each sedation provider is well trained in emergency medicine in an adverse event. 

Other negatives include a separate driver to and from the appointment due to lingering sedative effects, similar to oral conscious sedation. It is unsafe for someone recovering to drive themself. There are also very specific preoperative requirements that must be strictly adhered to such as nil per os (NPOMeans ‘nil per os’ in latin. This refers to a time frame in which the patient has had nothing to eat or drink.) for 6-8 hours and only clear liquids up to 2 hours prior to the procedure. This is a safety precaution to prevent aspirationThe act of drawing a liquid into another vessel or organ. This can occur during administration of local anesthetic if the needle is in a blood vessel. This can also occur if someone vomits water during sedation and inhales the liquid into their lungs. of any food/liquids in the event the patient vomits. 

Another barrier is cost, as IV sedation is more costly than minimal sedation. However despite the negative aspects, IV sedation is one of the safest and most effective ways to address moderate to extreme dental fear and anxiety for the general population.

Deep Sedation and General Anesthesia

These are the deepest levels of sedation that require extensive training and are often handled by a different provider than who is doing the dental work. For instance with in-office pediatric sedation, general anesthesia is often performed by an anesthesiologist and the dental work by a pediatric dentist. These deep levels of sedation are generally not required by most physically healthy patients who typically only need moderate or minimal sedation, however pediatric patients are an exception. The classes of drugs used at these levels are a combination of benzodiazepines, opioids, and most commonly general anesthetics.

Who Can Get Dental Sedation?

Almost everyone is able to get some form of sedation, save for those who are extremely sick. Those who are too sick for dental sedation are often at risk of dying, in which case dental treatment is often not a high priority. These patients are class V or higher on the ASA classificationA way to categorize patients in terms of overall health. scale¹⁴https://www.asahq.org/standards-and-guidelines/asa-physical-status-classification-system which is a system that categorizes patients according to how healthy they are. 

The ASA classification has varying levels as well:

• ASA I – A normal, healthy patient with no acute or chronic diseases
• ASA II – A patient with mild systemic disease. These mild diseases do not substantially limit functionality. An example is a patient who has well controlled hypertensionHigh blood pressure. with medication.
• ASA III – A patient with severe systemic disease. These patients have substantial functional limitations and often have one or more moderate to severe diseases. An example is a patient with poorly controlled hypertension and diabetes mellitus type 2. 
• ASA IV – A patient having severe systemic disease(s) that pose a constant threat to their life. An example is a patient with cardiovascular disease, poorly controlled hypertension and a recent myocardial infarctionAlso known as a heart attack, this occurs when there is a blockage of blood flow to the heart itself. (heart attack).
• ASA V – A moribundClose to the point of death. patient that is not expected to survive without medical intervention or operation. 
• ASA VI – A patient that is declared brain dead. At this time, the patient’s organs are removed for donor purposes, should they be an organ donor.

Depending on the level of sedation, people with the different ASA classifications can be sedated safely. However for most cases, especially routine moderate sedation, ASA I and II are the best candidates. The health of the patient must be seriously considered to prevent adverse outcomes. The patients that benefit the most from dental sedation are ASA I and II who have moderate to severe dental anxiety. These patients tolerate the drugs and procedures well and also have the best, most comfortable dental experience while receiving the necessary treatment. A win-win situation for everyone. 

Even those who have ASA III or ASA IV can be sedated, however due to the complexities of managing the health factors, these unhealthier patients often require a specialist for sedation dentistry.

What Procedures are Best to be Sedated for?

While it varies from person to person, patients planned to have invasive procedures such as oral surgery will typically benefit the most. Other procedures include long and potentially anxiety inducing procedures such as endodonticsA dental specialty that deals with root canals. These root canals may be completed non-surgically or may require a surgery to complete. (root canals) or implantology. However the truth of the matter is any procedure that prevents the patient from receiving the necessary treatment is a good procedure for sedation.

What Does Dental Sedation Feel Like?

While the effects will vary depending on the combination of drugs administered, a general euphoric sense, relaxation, and calmness is felt, if any memory actually exists. For minimal sedation, patients will have a range of experiences. With nitrous oxide, the patient will feel a sense of calm, relaxed, and even giddy. The patient will be aware of what is happening and will be able to hold a normal conversation. The onset and offset of the sedation is very quick. For oral conscious sedation, the patient can experience very similar feelings as with nitrous oxide. If given a benzodiazepine such as triazolam, the patient may not remember anything due to the amnestic properties.

For moderate sedation, many clinicians choose to use drugs with anterograde amnestic properties. This prevents the conversion of short term to long term memory, leading patients to forget the entire procedure except the IV cannulationThe process of placing a cannula within a vein to provide access to the venous system to administer drugs.. However, patients may also forget the IV cannulation as well if given sedatives prior to coming to the office. For anyone with moderate to severe anxiety, this experience is typically best since the patient will have no recollection of the visit.

For deep sedation or general anesthesia, since the patient is unconscious, there is no recollection of the event and will only need to deal with the post op discomfort once recovered.

How Should I Prepare for Dental Sedation?

The preparation will vary depending on the level of sedation administered. If you have any questions, contact your local dental office. It is critically important that the patient understands and follows the pre-operative instructions. Failure to do so may result in the inability to complete the procedure. It is all done to ensure the safety of the patient.

Minimal sedation with nitrous oxide requires no preparation, as you can drive to and from the office. You can eat or drink prior to the procedure as necessary to keep you comfortable during the dental procedure.

Moderate sedation requires NPO (no eating) for 6-8 hours and clear liquids up to 2 hours prior to the procedure. Transportation to and from the appointment is also required as patients are not allowed to drive themselves. The transportation needs to have a vested interest in the well being of the patient. A taxi, Uber, or Lyft are not appropriate forms of transportation. This is also the same for deep sedation.

It is important that the patient be truthful about what was ingested prior to the appointment, including any alcohol or recreational drugs in addition to a truthful medical history. While more difficult, smoking cessation for as long as possible prior to treatment is also important. If you have any concerns, ask your dental office prior to your appointment so that you understand what can be done and what absolutely cannot be done to ensure the procedure is completed safely.

How Much Does Sedation Cost?

Depending on the level of sedation, type of provider, and length of the procedure, sedation can cost anywhere from $20 to $1,000. Nitrous oxide sedation is the least expensive with the overall cost increasing as the depth of sedation increases. The cost of moderate IV sedation will vary on the office and either costs at a flat rate or an initial rate then additional cost every 15 minutes. Deep or general anesthesia will be the most expensive as they need to be completed by a specialist, either a physician or dental anesthesiologist. The rate will also vary, however it commonly follows the same pricing scheme as with moderate IV sedation.