Dental Treatment under Sedation
Sedation is defined as a medically controlled state of depressed consciousness. The term conscious sedation implies that the patient is awake and able to respond to verbal and physical stimulation. The protective reflexes are maintained and the patient retains a patent airway independently and continuously. The term deep sedation denotes a deeper state of depressed consciousness from which the patient is not easily aroused, but is still maintaining protective reflexes even if they are reduced. General anaesthesia is an even deeper state in which the patient is fully unconscious. Sedation and general anaesthesia may be obtained by the same drugs, as the level of depressed consciousness is dependent upon the dose of the drug.
There are a number of publications that present guidelines for oral health professionals about the use of sedatives and general anaesthesia (Glassman 2009). Most of these suggest that only conscious sedation should be administered by a dental practitioner working alone (Department of Health 2003; Norwegian Medicines Agency 2003; The Royal College of Anaesthetists 2007) since treatment procedures in the oral cavity take place in close proximity to the airways. Deep sedation and general anaesthesia are accompanied with risks of having fluids and foreign bodies slip into the airways, since the protective reflexes are partially or totally lost. These procedures should therefore be administered by an anaesthetist assisting the dentist during treatment.
Pain and Pain Control
Pain is closely related to dental anxiety and phobia since a majority of patients report painful stimuli during dental procedures (procedural pain) as one of the most important reasons for their anxiety (Locker, Shapiro and Liddell 1996). Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage (International Association for the Study of Pain 2011). It is always subjective and each individual learns the meaning of the word through their experiences related to injury in early life.
Tissue damage is the most obvious painful stimuli during a dental procedure and this is most easily prevented by the use of local analgesia. However, there are a number of additional factors known to affect the individual perception of pain, such as classical conditioning, peripheral and central sensitization, biological variations, previous pain experience, context and a variety of psychological factors (Melzack 1999). A typical example in dentistry is the very anxious patient who perceives a gentle touch of the explorer on the top of a tooth and the sound of the drill as painful.
Prevention of painful dental treatment must therefore be based on a combination of psychological and pharmaceutical interventions. Before the choice of the possible use of local analgesia, analgesics, sedatives and other drugs, it must be decided in which psychological context these tools should be applied. Cognitive behaviour therapy (CBT) of phobic patients therefore must include these aspects.
Indications for Sedation and General Anaesthesia
Even if some dentists see sedation and general anaesthesia as alternatives to psychological treatment of patients with dental anxiety and phobia, the purpose of this chapter is to describe them as supplements. The main reason for this is that the objective of this book is the long-term goal of treating patients with dental phobia and the primary intention is therefore to treat the anxiety disorder, which in turn will make the patient able to cope with necessary dental treatment. Sedation and general anaesthesia alone may be excellent tools in cases where the dental treatment need is the primary goal (Jackson and Johnson 2002), e.g. in emergency cases, but their effectiveness in reducing the dental anxiety is small or totally absent (Berggren 1986; Hakeberg et al. 1993).
Conscious sedation implies that the patient is awake and capable of communicating with the dentist and usually the patient is able to recall what has been going on during the session. Since the anxiety and tension are reduced, communication with the therapist may be facilitated. This is the key factor in order to understand the potential of using conscious sedation as an adjunct to psychological interventions.
There are two main indications for use of conscious sedation in this setting:
- Before dental treatment: prevention of anticipatory anxiety.
- During dental treatment: as supplement to psychological techniques during exposure to anxiety-provoking dental procedures.
Prevention of anticipatory anxiety
Avoidance behaviour is typical for patients with dental anxiety and phobia and they frequently cancel dental appointments (Skaret et al. 1999). Even if their intention for showing up is sincere, their anticipatory anxiety and catastrophic thoughts increase as the time of appointment approaches, frequently after a sleepless night. A sedative with anxiolytic and hypnotic properties may be a tool for such patients in helping them to a good night’s sleep and reducing their anticipatory anxiety, thereby facilitating their intention of keeping the appointment and making them available for psychological treatment.
Conscious sedation during treatment
As previously stated sedation may be effective in helping anxious patients cope with dental treatment (Jackson and Johnson 2002). However, it is also the experience that conscious sedation in dentistry does not work for patients with high dental anxiety or phobia and many of them are not even willing to try it. One reason seems to be the fact that these patients usually have a strong feeling of lack of control in the dental chair and the prospect of being sedated increases this feeling. And, since conscious sedation implies that they are awake, their catastrophic thoughts are maintained. These facts limit the indications for conscious sedation as an adjunct to the psychological techniques in which the primary goal is treating the anxiety disorder.
Generally it is suggested that sedation is used for two main purposes in connection with CBT of phobic patients:
- After having established a good relationship between patient and therapist and the patient is confident with being sedated, conscious sedation during exposure to the most frightening stimuli may result in easier and quicker acceptance of the stimuli. This assumes a dose of the drug that enables the patient to communicate well and perceive the outcome of the treatment. The drug must not have an amnesic effect so that the patient is able to remember his newly acquired coping skill. This approach is mostly indicated when CBT is performed in vivo by a dentist as therapist and where the anxiety treatment and dental treatment are performed simultaneously.
- When the CBT has resulted in good acceptance of the most general dental treatment modes, but there are still certain procedures that the patient perceives as extremely demanding, sedation may be a choice to facilitate coping with these particular procedures. A prerequisite is that the patient is confident with being sedated and finds it helpful.
Deep sedation during treatment
Deep sedation is an anaesthetic state very close to general anaesthesia, since the patients are more or less asleep and the protective reflexes are reduced. The indications for deep sedation in combination with CBT may therefore be similar as for general anaesthesia (see below).
The main indication may be emergency cases when dental treatment must be performed in patients lacking the ability to cooperate during this treatment. Since the protective reflexes are reduced, particularly the patient’s ability to cough if foreign bodies enter the larynx, the challenge for the operating dentist is to secure the airways during treatment. Use of a rubber dam is a good preventive measure during general operative dental treatment. In cases of surgical treatment the operator should be extremely careful in preventing blood, tooth fragments, surgical gauze and other elements slip into the throat of the patients.
Deep sedation may be acquired by use of the same medications as for conscious sedation, but with higher doses. Depending on the type of drug and route of administration, the level of sedation is more or less easy to control. Intravenous sedation and inhalation sedation are most easily controlled since the drug may be titrated slowly with almost immediate dose response. The individual responses to drugs given by the oral, nasal and rectal routes are much more unforeseeable and there may be situations when the dentist is faced with cases where the level of sedation is deeper than expected. If this happens and dental treatment proceeds, a major focus must be kept on preventing aspiration of foreign bodies from the oral cavity.
Indications for general anaesthesia (GA)
Patients with dental phobia often request dental treatment under general anaesthesia, which they consider to be a feasible way of having their dental problems solved. Even if this is effective in completing dental operative procedures, it is well known that there is no or limited effect on the dental anxiety disorder (Berggren 1986; Hakeberg et al. 1993). It is also our experience that if such patients are offered treatment under general anaesthesia before any psychological treatment of their phobia, they may not come back for such treatment after the GA. Their relief at having their dental problems fixed reduces their motivation for anxiety treatment and their avoidance behaviour is maintained. There is therefore a high risk that the main problem, namely the anxiety disorder, will result in further dental neglect and more oral diseases in the future.
Based on these considerations and experience at the Center for Odontophobia, University of Bergen, there are two alternative ways to successfully combine CBT and GA in treatment of phobic patients who request dental treatment under GA: