1. Anesthesia and Sedation20
Anesthesia and Sedation

2. Anesthetics and Sedation
Reduce pain
Relieve anxiety
Different levels of sedation can be achieved based upon procedural need and patient response
Many patients are very anxious about dental care and treatment. Sedation is one method of managing the anxiety of the patient. Anesthesia can also be used to control the pain the patient experiences. Depending on the need, various levels of sedation can be achieved from conscious sedation to deep sedation.

3. Conscious Sedation Causes an altered state of consciousness
Patient can still communicate
May experience headache, nausea, brief periods of amnesia
Conscious sedation places the patient in an altered level of consciousness. The patient is still able to communicate and respond to questions. This form of sedation serves to lower levels of pain and discomfort. The patient may experience a headache, nausea, and brief periods of amnesia following conscious sedation.

4. IV Sedation Administered directly into the bloodstream
Patient may be conscious but in a deeply relaxed state
Patient has no memory of events taking place while sedated
Anesthetics are administered directly into the bloodstream and remain in place throughout the procedure.
The patient may remain conscious but is in a deeply relaxed state.
The patient often has no recollection of the events that took place while under anesthetic.
This form of sedation keeps patient’s relaxed, comfortable, and pain free.

5. Oral Sedation Prescription taken before appointment
May make the patient calm and drowsy or calm and relaxed
Oral sedation is achieved by taking a medication the night before a dental procedure.
This may be prescribed for the patient who is extremely anxious about the procedure to be done.
Benzodiazepine is often used and can be a sedative hypnotic, which makes the patient calm and drowsy or an anti-anxiety drug, which makes the patient calm and relaxed.

6. Inhalation Sedation Odorless and colorless gases Inhaled through mask
Patient doesn’t remember much of procedure
Inhalation sedation may be used when it is difficult to achieve IV sedation.
The anesthetics are administered in a gas form by inhalation through a mask.
This will cause the patient to become sleepy and serves to relieve pain.
The patient often doesn’t remember much of the procedure. It is not long-lasting so the patient must be carefully monitored.

7. Intramuscular Sedation
Injection into muscle of upper arm or thigh
Not commonly used
Takes 20 to 30 minutes to take effect
Intramuscular sedation is injection of an anesthetic directly into the muscle of the upper arm or thigh.
It is not commonly used but may be seen in pediatric practices.
It takes 20 to 30 minutes for the anesthetic to take affect with this route of administration.

8. General Anesthesia Creates an unconscious state
Must be carefully controlled
Sensation and feeling is lost
General anesthesia provides a deep level of sedation that creates an unconscious state.
The patient’s vital signs must be closely monitored and the patient will be on a ventilator for the duration of the sedation.
General anesthesia alters and depresses the patient’s central nervous system. The patient will loose all sensation and feeling.

9. Topical Anesthesia Numbs a particular area
Used prior to local anesthetic
Desensitizes the oral mucosa
A topical anesthetic is often used prior to the local anesthetic.
The nerve endings in the mucosa are desensitized causing numbness.
This alleviates the sensation of the pinch of the needle used to inject the local anesthetic.

10. Local Anesthesia Produces a deadened or pain free area
Sensory impulses are temporarily blocked
Affects the nerve fibers carrying messages to brain
Local anesthetics are used to reduce the sensation of pain, touch, and heat to a particular area.
This type of anesthetic works on the nerve fibers to block sensory impulses.

11. Topical Anesthetics Used for the following: Subgingival scaling
Root planing
Seating crowns
Placing matrix bands
Periodontal probing
Preparation for local sedation
Repress gag reflex
We want the patient to be cooperative, conscious, and relaxed.
Topical are available in gels, ointments, liquids, or sprays.
This anesthetic helps prepare the area to accept a needle without pain. Usually benzocaine or lidocaine.
Can cause an allergic reaction up to 24 hours after the application. This reaction may cause swelling, redness, ulcerations, difficulty swallowing and difficulty breathing.
A toxic reaction can also occur and initially the patient will become more talkative, apprehensive, and excited with an increase in pulse and blood pressure.

12. Placing Topical Anesthetic
Determining factors for how much a patient should receive may include:
Age
Weight
Physical condition
Liver function
Topical 5% to 10% anesthetic solution
Local consists of 2% anesthetic solution.
Patient reactions may include:
Talkative
Apprehensive
Excited
Increased pulse and blood pressure
Patient becomes sleepy afterward

13. Local Anesthetics Used to manage pain
Can be short, intermediate, or long in duration
Vasoconstrictor
Local anesthetics are primarily used to alleviate and control pain during a procedure.
They come in liquid form and are injected into the tissues.
A short-duration local will last about 30 minutes. An intermediate-duration local will last about 60 minutes.
A long-duration local will last longer than 90 minutes.
Local anesthetics may contain vasoconstrictors, which constrict blood vessels to reduce blood flow to the area of the injection site.
Vasoconstrictors reduce the levels of anesthetics entering the blood stream thus reducing the chances of a toxic reaction and decreases blood flow at the site.
Epinephrine is the most commonly used.

14. Possible Complications of Local Anesthetics
Toxic reactions
Patient becomes ill
Many factors
Paresthesia
Numbness does not go away as expected
Patient with toxic reaction possibly because of an overdose, the type used, absorption rate, or individual characteristics. Symptoms may include:
Drop in blood pressure
Nausea and vomiting
Pallor
Convulsions
Muscular twitching
Apprehension
Temporary numbness
Paresthesia could last a few days or up to eight weeks. Causes for this may include:
Nerve sheath damage during injection
Hemorrhage: creating pressure on nerve
Contamination of anesthetic

15. Types of Injections Local infiltration Field block Nerve block
Injection near small terminal nerve branches
Field block
Injection near large terminal nerve branches
Nerve block
Injection near main trunk nerve
Local infiltration used for various dental treatments include root planning, soft tissue inclusion for biopsy, gingivectomy, and frenectomy.
Field block infiltration are given near the apex of the tooth and involve one or two teeth. Usually, the patient feels numb within two to three minutes.
Nerve block eliminates sensations over a larger area than infiltration or field block. Used to numb an entire region.
Usually takes effect within five minutes.
Local infiltration - surrounding tissue or one tooth
Field blocks - one or two teeth
Nerve blocks - entire quadrant

16. Maxillary Arch Injection Sites
Infiltration (field block)
Anterior superior alveolar nerve block (infraorbital nerve block)
Middle superior alveolar nerve block
Posterior superior alveolar nerve block
Greater palatine nerve block
Nasopalatine nerve block
Maxillary nerve block – all injections affect separate teeth and tissues.

17. Anesthetic Setup
Health history, cotton tip applicator tip, topical.

18. Aspirating Syringe
Various types of syringes may be used in dental procedures; most common is the aspirating syringe.
Aspirating syringe allows operator to verify that they have not penetrated a blood vessel.
Harpoon of syringe is retracted; if blood appears in syringe then needle is repositioned.
Parts of the Aspirating Syringe
Thumb ring
Finger grip/bar
Syringe barrel
Plunger
Harpoon
Threaded end of the syringe

19. Components of a Needle Needle length
Short (1 inch) used in infiltrations and field blocks. Periodontal ligament injections.
Long (1-5/8 inch) used for nerve blocks, maxillary and mandibular, reaches posterior areas, for areas that require penetration of thicker tissue.
Needle Gauge Sizes... the smaller the gauge the larger the diameter of the needle.
25 gauge
27 gauge
30 gauge
Needle Parts
Bevel
Shank
Hub
Syringe end

20. Needle Care and Handling
Maximum of four penetrations
Stick protection
Caps and shields
Proper disposal
OSHA guidelines
Sharps container
Procedure if stick occurs
OSHA Bloodborne Pathogens protocol
Procedure if needle stick occurs
Immediately squeeze the area of the needle stick or puncture to make it bleed.
Go to a sink and wash the wound area with an antimicrobial soap.
Notify the dentist and find out which patient the instrument was used on.
Review the patent’s chart and medical history.
Follow OSHA protocol for occupational exposure to Bloodborne Pathogens.

21. Anesthetic Cartridge Components
Parts of the Anesthetic Cartridge
Glass cartridge
Rubber stopper or plunger
Aluminum cap
Diaphragm

22. Retracting Harpoon
Left hand retraction of the piston rod of an aspirating anesthetic syringe.

23. Loading Cartridge into Syringe
Technique for placing a cartridge in an aspirating syringe.

24. Engaging Harpoon
Engage the harpoon with pressure on the finger ring (bar).

25. Placement of Needle into Syringe
Open the cap of the needle.

26. Passing the Syringe
After drying the inside tissue with a gauze, place topical anesthetic on injection site, and pass the syringe.

27. Disassembling the Syringe
Retract the piston to release the harpoon from the cartridge and remove the cartridge from the syringe.

28. Intraosseous Anesthesia
Cancellous bone injected directly
Special equipment required
Anesthetizes the following:
Bone
Soft tissue
Root
Teeth
Single or multiple teeth
Places local anesthetic directly into the cacellous bone.
Lip and tongue do not become numb.

29. Periodontal Ligament Injection
Used for pulpal anesthesia of one or two teeth in a quadrant
May be an adjunct to another injection where patient is partially anesthetized
Aids in diagnosing abscessed teeth
This technique involves inserting the needle into the gingival sulcus along the axis of the tooth to be anesthetized.

30. Periodontal Ligament Injection System
Developed in 1905; technique is becoming popular today again.
Often used with other types of injections.
Diagnosing abscessed teeth.
Outcome is pulpal anesthesia.
Technique
Inserted into the gingival sulcus of the tooth
Requires special pressure syringes

31. Intrapulpal Injection
Delivered directly into nerve chamber
Procedures
Root canal therapy
Severe abscess
This injection may be used when there is difficulty in securing numbness in the patient by traditional methods.

32. Electronic Anesthesia
Used with nitrous oxide provides a better effect
Used in the following procedures:
Placing restorations
Muscle relaxation
Determination of centric occlusion
Used alone, electric anesthesia has had low to moderate levels of success. When used in combination with nitrous oxide the effects are improved. This type of anesthesia can be used in patients who have an adverse reaction or are allergic to local anesthetics or who are fearful of injections.

33. Computer-Controlled Local Anesthesia Delivery System
Pain-free injections
Used for all traditional infiltration and block injections
The computer-controlled injection system uses a microprocessor to deliver controlled pressure and volume of anesthetics to a site. The microprocessor adjusts to the resistance of the tissues and offers a pain free injection.

34. Nitrous Oxide Safe, stable, non-flammable gas
Relaxes and comforts the patient
Some states allow dental assistants to perform this task under dentist supervision. Other states only allow assisting dentists.
Nasal hoods, scavenging circuit.
Asking the patient how they are feeling is key to adjusting the flow for that specific patient.
First discovered by Joseph Priestly in the early 1770s. It was thought the gas would cure diseases.
Horace Wells, a Connecticut dentist, was the first to use nitrous oxide as an anesthetic during dental surgery in the early 1800s.

35. Nitrous Oxide Contradictions Blocked nasal passage
Emotional instability
Drug users
First trimester of pregnancy
Risk of bone marrow suppression
In-vitro fertilization procedures
Neurological complaints