Creates a numbing feeling that eliminates the feeling of sensation in a specific area without loss of consciousness
Local Anesthesia
routinely referred to as analgesics
Pain relievers
what is most useful for pain control
Opium
Early methods of pain reduction included
Religious techniques of scaring of demons and praying for the touch of God to stop the suffering
PLants and herbs, include roots, berries, and seeds became the prominent method for treating pain
A new compound containing Salicylic acid was introduced as what?
Aspirin in 1899, it was highly effective as an analgesic and antipyretic
The first local anesthetic
Cocaine
What remains the most popular anesthetic used in dentistry in the US
Lidocaine
What are the two vasoconstriction drugs
epinephrine
levonordefrin
how many states permit the administration of nitrous oxide by dental hygienists
33
what is it called when you are anxious and nervous during treatment
Dental-phobia
Studies suggest that pts who are fearful of dental tx may have?
elevated blood pressure
elevated heart rate
Salivary cortisol levels
what are some clinical signs of moderate anxiety in the dental chair
unnaturally stiff posture nervous play with tissue white knuckle syndrome Perspiration on forehead and hands over willingness to cooperate with clinician quick answers
What type of appointments should you have for pts what have anxiety
shorter appointments, even through more app. may be needed, may help some pts reduce stress levels, as can scheduling pt during specific time periods of the day
What local anesthetics was available in US in 2000
Articaine 1969
What pts have an higher tolerance of pain
older pt than younger
Are nerve tissues that lie in the periphery or (outer regions) of the nervous system, consisting of 31 pairs of spinal nerves arising from the spinal cord and 12 pairs of cranial nerves arising from the brain
Peripheral nervous system (PNS)
What are the two divisions of the CNS and PNS
Afferent and efferent divisions
which division consists of all incoming information traveling alone sensory or afferent pathways
Afferent
Which division consists of all outgoing information along motor or efferent pathways
efferent
These are the basic functional unit of the nervous system that manipulate information and respond to either excitation or inhibition
Nerve cell (neurons)
is an excitable cell that is the basic functional unit of the nervous system, specialized in sending impulses and making all nervous system functions possible
The neuron
Each axon is surrounded by a layer of connective tissue called
Endoneurium
The nerve fibers are bundled together into groups called
Fascicles
Each fascicles is wrapped in a layer of connective tisse called the
Perineurium
The entire nerve is wrapped in a layer of connective tissue called
Epineurium
what nerve conducts signals from sensory neurons to the spinal cord or brain (carry toward)
Afferent nerves
what nerve conduct signals away from the brain or spinal cord along motor neurons to their target muscles and glands (carry away)
Efferent nerves
What causes more allergic reaction amide or ester
Ester
Along myelinated nerve fibers, gaps in the sheath between adjacent Schwann cells are called
Nodes of Ranvier
What are the gaps formed between the myelin sheaths generated by different cells called
Nodes of Ranvier
also known as a nerve impulse is a spike of positive and negative ionic discharge that travels along the membrane of a cell
Action potential
This occurs once the peck of the action potential is reached and the membrane potential begins to move back toward the resting potential
Repolarization
Local Anesthetic drug act mainly by inhibiting sodium influx through sodium- specific ion channels in the neuronal cell membrane; in particular that so- called
voltage-gated sodium channels
Local Anesthetic agents are divided chemically into two groups:
ester
amides
Due to the high degree of hypersensitivity to injectable esters, all injectable local anesthetic manufactured for dentistry today are in
the amide group
Local anesthetic molecule consist of 3 components
- Lipophilic aromatic ring
- Intermediate hydrocarbon ester or amide chain
- Hydrophilic terminal amine
There are 2 major routes of delivery of local anesthetic drugs
Topical
Submucosal injection
drugs applied to the surface of mucosal tissue that produce local insensibility to pain
Topical anesthetics
injections of local anesthetics are more effective than topical routes of administration
Submucosal
Refers to the physiological effects of drugs on the body an the mechanisms of drug action and its relationship between drug concentration and effects
Pharmacodynamics
Higher pKa = fewer base molecules =
Slower onset of action
Lower pKa = more base molecules =
Faster onset of action
IS the study of the action of drugs within the body
Pharmacokinetics
The period from local anesthetic deposition near the never trunk to profound conduction block,
The onset of action
What is the primary factor determining the onset of action
pKa
Is defined as the time interval between the initial deposition of the anesthetic solution at the nerve site and complete conduction blockage
induction time
Increased tolerance to a drug that is administered repeatedly
Tachyphlaxis
What are vasodilators and produce a pharmacologic effect on blood vessels, varying slightly from type to type
All local anesthetics
THis is the period of time it takes for 50% of the drug to be metabolized/removed from the body
Half-life of a local anesthetic
What organ is responsible for the entire metabolic process of most amides?
Liver
The rate of biotransformation is slower in what type of pt
Significant liver dysfunction (cirrhosis) or pt with lower hepatic blood flow, causing an increased rick of systemic toxicity
What organ is the primary excretory organ for the metabolites of all local anesthetic agents
Kidneys
what are important additives to the local anesthetic solution because of their ability to constrict blood vessels
Vasoconstrictors
Two vasoconstrictors that are added to local anesthetic drugs available in the US are
epinephrine
levonordefrin
Epinephrine is administered intravenously, it has a half life of
1 to 3 min
The maximum recommended dose per visit of epinephrine for healthy pts are
0.2mg
The maximum recommended dose per visit of epinephrine for a cardiovascular compromised pt or a pt with tx modifications
0.04mg
Side effects of overdose of vasoconstrictors only last
5-10mins
Maximum recommended dose per visit of levonordefrin for healthy pt is
1.0mg
Maximum recommended dose per visit of levonirdefrin for a cardiovascularly compromised pt or a pt needed tx modifications is
0.2mg