Most dental cases can be done under local anesthesia alone or sometimes in conjunction with an oral sedative and nitrous oxide sedation. However, certain complex cases, anxious and special needs patients, and children may require a more controlled and deeper level of anesthesia. The degree of anesthesia in such cases can vary between moderate-deep sedation and general anesthesia.
In order to put someone to sleep an intravenous needs to be started. Children receive an injection or drink to sedate tem then they receive a gas/vapor and once they are asleep the intravenous is started. Adults who can tolerate intravenous placement do not receive an injection, pill or mask. Waking up following this type of start to anesthesia is quick and you feel rather awake. If the adult patient requires a pill to reduce anxiety prior to the placement of the intravenous catheter, the recovery will be prolonged and you will feel tired and sleepy for a few hours after treatment.
| General Anesthesia
General anesthetics produce an unconscious state. In this state a person is:
- unaware of what is happening
- free from any memory of the period of time during which he or she is anesthetized
General anesthesia can be administered as an inhaled gas or an injected liquid. There are several drugs and gases that can be combined or used alone to produce general anesthesia. The potency of a given anesthetic is measured as minimum alveolar gases. (Alveolar is the area in the lung where gases enter and exit the partial pressure of a gas at which 50 percent of humans will not move to a painful stimulus (e.g. skin incision). Injected liquid anesthetics have a “MAC equivalent” which is the blood concentration of the liquid anesthetic that provides the same effect. Using MAC as a guideline, the amount of anesthetic given to a patient depends on that particular patient’s needs.
When anesthetics reach the bloodstream, the drugs that affect the brain pass through other blood vessels and organs so they are often affected too. Therefore, patients must be carefully monitored. The anesthesiologist continuously monitors the patient’s heart rate, heart rhythm, blood pressure, respiratory rate, and oxygen saturation. Some patients may have even more extensive monitoring depending on their health and which type of procedure or surgery they are having. Most adults are first anesthetized with liquid intravenous anesthetics followed by anesthetic gases after they are asleep. Children, however, may not like having an injection or intravenous catheter placed in them while they are awake. Therefore, they often breathe themselves to sleep with anesthetic gases given through a mask.
Dental Sedation is a technique that can be used to reduce excitement or anxiety to allow patients to receive the dental treatment they need.
Varying degrees of dental sedation can be utilized as outlined below:
- Minimal Sedation: patients respond normally to verbal commands. Although cognitive function and coordination may be impaired, breathing in unaffected
- Moderate Sedation: patients respond purposefully to verbal commands, either alone or by light stimulation. No interventions are required to maintain breathing. This is also referred to as “Conscious Sedation.”
- Deep Sedation: patients cannot be easily aroused but respond to painful stimulation. The ability to breath may be impaired. Patients may require stimulation. Patients may require assistance in maintaining a patent airway.
- General Anesthesia: patients cannot be aroused, even by painful stimulation. The ability to independently breath is often impaired. Patients often require assistance in maintaining a patent airway.
| Local Anesthesia
Local Anesthesia involves numbing a small area by injecting a local anesthetic under the skin just where an incision is to be made. When used alone, this type of anesthesia has the least number of risks. Local anesthetics are thought to block nerve impulses by decreasing the permeability of nerve membranes to sodium ions. There are many different local anesthetics that differ in absorption, toxicity, and duration of action.
One of the most commonly used local anesthetics is Lidocaine (Xylocaine). Lidocaine can be administered as an injection or placed topically on mucous membranes. A topical anesthetic that is gaining popularity for anesthetizing the skin prior to painful procedures, such as injections, is known as eutectic mixture of local anesthetics (EMLA) cream which contains lidocaine and prilocaine. This white cream is placed on the skin and then covered with an occlusive dressing for approximately one hour to obtain a good numbing effect. In addition, EMLA can be used to numb the skin prior to giving injections or pulling superficial splinters.
The use of anesthesia is safe and effective when properly administered by trained individuals. The American Dental Association strongly supports the rights of appropriately trained dentists to use these modalities for the management of dental patients and is committed to ensuring their safe and effective use.