Sedation dentistry refers to the use of pharmacological agents to induce relaxation and often sleep in a patient prior to and during a dental appointment. It is also known as conscious sedation, where it is defined as "a technique in which the use of a drug / drugs produces a state of depression of the central nervous system enabling treatment to be carried out, but during which verbal contact with the patient is maintained throughout the period of sedation".Programme, O. (2023). GUIDELINES FOR CONSCIOUS SEDATION IN DENTISTRY FOR ADULT PATIENTS. https://hq.moh.gov.my/ohp/images/pdf/Guideline_for_Conscious_Sedation_in_Dentistry_for_Adult_Patients.final-compressed.pdf The pharmacological agents used differ depending on patient, level of sedation desired and medical professional administering the sedation medications. The medications can belong to a class of drugs called sedatives, which exert their action by depressing the central nervous system, specifically those areas concerned with conscious awareness. Medications used to obtain sedation often include a benzodiazepine (i.e. alprazolam, triazolam, diazepam), opioids (i.e. fentanyl), dissociative (i.e. ketamine) and anti-histamines (i.e. hydroxyzine, Benadryl).
Sedation dentistry is essential for children to be able to cope with traumatic procedures such as extraction, restorative procedures.
Every practitioner should be aware of the viable and appropriate sedative measures while incorporating anxiety-reducing procedures.
Indication for Nitrous Oxide/Oxygen Inhalation Sedation Primary IndicationMalamed, S. F. (2010). Sedation: A guide to patient management (5th ed.). Mosby Elsevier.Specific IndicationsRationale & MechanismsPsychological Management of Fear & Anxiety Procedures: For procedures generally considered non-threatening, which may be traumatic for some patients. Considered the most nearly ideal sedation technique for anxiety. Readily controllable, making it suitable for a wider range of procedures than typical moderate sedation.Medical CompromiseCardiovascular Disease:
Angina Pectoris Heart Failure Severe Cardiac Dysrhythmias Post-Myocardial Infarction High Blood Pressure Acute Myocardial Infarction (in emergency settings) Reduces myocardial O₂ demand by decreasing anxiety and workload. Increases O₂ delivery to the myocardium (30-70% O₂ vs. 20.9% in air). Provides analgesia, reducing pain-induced stress. Proven success in emergency medicine (e.g., Entonox, Dolonox).Respiratory Disease:
Asthma Note: Chronic Obstructive Pulmonary Disease (COPD) is a relative contraindication, but can be used with caution. N₂O is a non-irritating vapor and does not precipitate bronchospasm. Sedation reduces stress, a known trigger for asthmatic episodes. Caution in COPD due to potential for apnea from elevated O₂, though this is rare.Cerebrovascular Disease:
Post-Cerebrovascular Accident ("Stroke") Elevated O₂ level minimizes risk of hypoxia-induced seizure activity or further neuronal damage. Safer than deep sedation techniques where hypoxia is more likely.Hepatic Disease:
Cirrhosis Hepatitis N₂O does not undergo biotransformation in the liver. It can be used without the risk of prolonged effect or increased plasma levels seen with drugs metabolized by the liver.Neurological Disorders:
Epilepsy and Seizure Disorders N₂O is not epileptogenic(does not induce seizures). Prevents stress-induced seizures. Safe when hypoxia is prevented by the technique.Pregnancy Considered the recommended sedation technique during pregnancy when combined with adequate O₂ (>20%). Medical consultation is suggested prior to use.Physical Reflex ManagementGagging (Hypersensitive Gag Reflex)
For impressions, radiographs, and procedures in the maxillary palatal and posterior mandibular lingual regions. Highly effective in eliminating or minimizing severe gagging. Practical for very short procedures where other sedation techniques (like IV) are less practical. Patient position (upright) can be modified as needed for the procedure and safety.
Applications of Nitrous Oxide Sedation in Dental Specialties Dental SpecialtySpecific Procedures & Clinical ScenariosBenefits & Mechanisms of Nitrous OxideRestorative Initial Examination of a patient in pain Removal of Provisional Crowns/Bridges from vital teeth Drying & Cleansing prepared vital teeth for cementation Occlusal Adjustment of crowns, bridges, or natural teeth Insertion of Matrix Bands or Wedges Use of Ultrasonic Instruments Elevates pain threshold, making sensitive procedures tolerable. Provides soft tissue analgesia (esp. for matrix bands/wedges). Reduces anxiety from drill noise/vibration (occlusal adjustment). Eliminates discomfort from short procedures where local anesthesia is often omitted.Periodontics Periodontal Surgery(esp. for anxiety and lengthy procedures) Initial Periodontal Examination & Probing Scaling, Curettage, and Root Planing Management of Necrotizing Ulcerative Gingivitis (NUG) Use of Ultrasonic Instruments Provides soft tissue analgesia, crucial for sensitive, inflamed tissues. Makes debridement of NUG-affected tissues tolerable. Relaxes the patient for lengthy procedures. Offers a reversible alternative to local anesthesia for hygiene procedures.Oral Maxillofacial Surgery Lengthy Surgical Procedures Incision & Drainage (I&D) of Abscesses Management of Localized Osteitis (Dry Socket) Suture Removal(difficult cases or sensitive tissues) Provides analgesia when local anesthesia is ineffective (e.g., due to tissue pH changes in abscesses). Makes irrigation/packing of dry socket more comfortable. Helps manage discomfort during difficult suture removalEndodontics Gaining Access to the Pulp Chamber in a "hot" tooth with inadequate anesthesia Placement of Rubber Dam Clamps on gingival tissue Instrumenting Root Canals Filling of Root Canals Raises pain reaction threshold, modifying the patient's perception of pain even if not eliminating it. Aids in reaching the point where an intrapulpal injection can be given. Provides comfort for procedures where local anesthesia is not typically used.Fixed Prosthodontics Impression Taking Placement of Gingival Retraction Cord Removal of Provisional Crowns/Bridges Adjustment of Castings (try-in & occlusal adjustment) Diminishes the gag reflex during impression taking. Elevates pain threshold for cord placement and cement removal on vital teeth. Reduces sensitivity to vibration/noise during occlusal adjustment of castings.Removable Prosthodontics Preparation of Abutment Teeth Occlusal Adjustments Impression Taking Fitting of Immediate Dentures at subsequent visits Manages tooth sensitivity and anxiety during tooth preparation. Aids psychological relaxation, allowing for more accurate muscle positioning for centric relation. Reduces discomfort from adjusting and fitting dentures on unhealed tissues.Orthodontics Impression Taking Placement or Removal of Bands and Wires Minimizes gagging during impressions. Soft tissue analgesia reduces discomfort from band/wire placement.Pediatric Virtually Unlimited Range of procedures where cooperation is needed. Same indications as for adults (anxiety, gagging, lengthy procedures). Highly valuable for managing fear and anxiety in children. Limitation: Requires the child's willingness to accept the nasal hood and breathe through the nose, which can be a challenge with uncooperative patients.Oral Radiology Placement of Intraoral Films Patients with Limiting Anatomy (shallow palates, exostosis, trauma) Anxious or Medically Compromised patients Highly effective at eliminating/minimizing the gag reflex. Reduces discomfort in patients with sensitive or unusual anatomy. Note: Care must be taken with tubing to prevent shadowing on radiographs.
Pharmacology of Common Sedative Agents
DescriptionMOAThings for patient to take note / exampleOral sedation Most commonly used drugs: Midazolam, temazepam Concentration: Oral: 0.25 to 1.0 mg/kg to a maximum single dose of 20 mg. Supplied - oral tablets 0.3–0.6 mg/kg. Syrup - 2 mg/ml Midazolam enhances the effect of GABA at GABA-a receptor, which increases the inhibitory neurotransmission in the central nervous system, causing analgesia When given orally as a premixed syrup or after being diluted with a pleasant, pH-balanced drink (such as apple juice), midazolam is quickly absorbed. The drug may start to take its effect within 15–20 min, lasting for around 30–45 min. Inhalation sedation is preferred over oral sedation because inhalation sedation is titratable, in that the dose can be adjusted based on the condition of the patient from time-to-time, however, oral sedation is a fixed dose.Inhalation sedation Most commonly used drugs: Nitrous Oxide (NO) / Oxygen aka "laughing gas" (others: ketamine) Concentration: approximately 25 ppm (45 milligrams per cubic meter) 70% nitrous oxide, 30% oxygen in the gas delivery system inhibits N-methyl-D-aspartate (NMDA) receptors (just like ketamine, as shown in the diagram) Reduces excitatory glutamate transmission Causes central nervous system (CNS) depression and analgesia You will be able to hear and respond to any requests or directions the dentist may have. A mask would be fitted properly. You will be told by the dentist to breathe slowly using your nose, and within a few minutes, you will start to feel the effects of NO gas, such as light-headed, tingling in the arms and legs. Some may even describe their arms and legs feeling heavy. Ultimately, you will feel calm and comfortable. After the procedure, 100% oxygen will be delivered for 5 minutes before removing the mask to clear the NO gas from the body.IV sedation Most commonly used drugs: Midazolam Midazolam enhances the effect of GABA at GABA-a receptor, which increases the inhibitory neurotransmission in the central nervous system, resulting in sedation, anxiolysis, and anterograde amnesia.UK
Midazolam for dental field
USA
Midazolam in combination with fentanyl Propofol
Japan
Midazolam Propofol in hospital settings Nasal sedation Most commonly used drug: Midazolam Midazolam enhances the effect of GABA at GABA-a receptor, which increases the inhibitory neurotransmission in the central nervous system, resulting in sedation, anxiolysis, and anterograde amnesia.UK
Intranasal midazolam, especially for paediatric
USA
Midazolam, and dexmedetomidine with increased popularity
China
Midazolam and dexmedetomidine which commonly used in paediatrics
Adverse effects of sedation dentistry
Adverse effectsDetailsCommonDrowsiness Patients may feel prolonged drowsiness after sedation, in which they may find it difficult concentrating or sleepy Nausea, vomitingPatients may feel nauseous or vomit after sedation Dry mouth Patients may experience dryness in the mouth or thirst after sedationHeadache Patients may experience headache after sedation, often caused by the contractions of the muscles of facial and scalp area that happens due to sedation Dizziness Patients may feel dizzy or lightheaded after sedationLess common/rareTemporary memory loss Patients may experience temporary memory loss in which they do not remember or recall what happened during the procedure Allergic reactionsPatients may be allergic to certain sedative medication used, developing allergic reactions like rashes Bruising There may be minor bruising or swelling of the skin at the area of intravenous injection site Respiratory issuesThere may be changes in respiratory rate, increases the risk of respiratory depression (breathing becomes slower/shallower than normal)Cardiovascular issues There may be changes in heart rate or blood pressure
Safety protocols Adherence to safety protocols while performing sedative procedures in dentistry is crucial to ensure safe and effective sedation in dental care with minimal risks.