Dh 102 final study guide

PSA landmarks

Maxillary tuberosities, mucobuccal fold above the 2nd molar, zygomatic process of the maxilla

MSA landmarks

Max mucobuccal fold above the maxillary 2nd premolar

ASA landmarks

Canine eminence, canine fossa, Max mucobuccal fold, max canine

Location of incisive foramen

Located palatal to the maxillary central incisors

what are the benefits of larger-gauge needles

Rigidity of larger gauge needle cause less deflection during significant tissue penetration causing greater accuracy

Needle breakage is minimized

Aspiration is easier to achieve and more reliable

No difference in patient comfort

Less pressure needed to administer the anesthetic agent, resulting in decreased pain and tissue injury

state the weakest part of the needle

The Hub

How much anesthetic does the standard local anesthetic cartridge contain

1\.8ml

A cartridge is meant to hold 2ml,

The rubber stopper is .2ml leaving only 1.8mm in the cartridge

which number to use in calculations if the patients weight X the anesthetics mg/lb is larger than the MRD

Always use the more conservative, lower number in the calculations

How is 20% benzocaine topical’s rate of absorption

Benzocaine exists entirely in its base form causing absorption into circulation to be slow

What is the location of the mental foramen

Located on the mandible usually in between the two premolars

Where is the location of lingual Foramen

Located on the anterior of the mandible under the genial tubercles

Location of mandibular foramen

Located on the inside of the ramus on the mandible

which injections require a long needle

Gow-gates injection

Inferior alveolar block

Infraorbital injection

Long buccal injection -we use a long needle only after IA injection, but otherwise a short needle is recommended if doing this by itself

What is the rule of thumb regarding various colors of needle gauges and sheaths

Different manufacturers use various color-coding to indicate needle length and gauge

There are no uniform guidelines for the color of needle sheaths(caps)

A single-use plastic or partially disposable syringe that utilizes a retractable plastic sheath that locks over the needle upon removal from tissue is called a safety syringe and does not have a particular color

What are the three commonly used needle lengths for intraoral injections

Long, short, and extra short needles

What are harmless nitrogen used to elimate oxygen from the cartridge

Smaller bubbles (1-2mm in diameter)

what is a warning that the cartridge has been frozen

Larger bubbles greater than 2mm in diameter

What are the manufacturers recommended for proper care of reusable syringes

Thorough cleaning and sterilization after use on each patient

Bent harpoons should be replaced

Following repeated autoclaving, reusable syringes should be dismantled and lubricated

what is the formula for calculating of cartridges a patient can have per patient weight

Multiple the mg/lb of an anesthetic by the patients weight and then divide by the mg in one cartridge

3\.2mg/lb x 200lb=640mg but MRD is only 500mg, so use the lower MRD

2%lidocaine 20x1.8=36mg

500mrd Divded by 36mg=13.5mg

What is the maximum dosage for medically compromised patient for 1:50,000 ratio

Can have 1.1 cartridges or 1

What is the maximum dosage for a medically compromised patient for 1:100,000

Can have 2.2 cartridges or 2

What is the maximum cartridges for medically compromised patient of 1;200,000

Can have 4.4 to 4 cartidges

How do you handle the MRD’s of medically compromised patient

Always decrease the MRD of the local anesthetic for patients who are medically compromised, elderly and children

The lowest effective dose should be given to any of the above patient as well as any patient

How are local anesthetic drugs expressed

In percentages

3% Mepivacaine plain

How are vasoconstrictor drugs expressed

They are expressed in ratios

1;100,000

how is the MRD determined in an anesthetic containing a vasoconstrictor

The MRD depends on which of the two drugs , anesthetic or Vaso, reaches its MRD first and is the limiting factor

In turn is determined by the medical status of the patient

if a patients MRD is 500mg and 245mg of 2% Lidocaine with epi 1:100,000 has already been used, how much more Meg’s of 2% Lidocaine with epi 1:100,000 can the patient recieve

500mg-245mg=255mg more of 2% LIdo with epi 1:100,000 which in charts would be 255mg-36mg=7more

what does the MRD depend on?

The patients health

It does not depend on the age or gender\*\*

Who is responsible for making sure the dental hygienist maintain continuing ed, credentials and professional compentency

Dental hygienists are responsible for their own licensure/credentials, and continue education

Know what the qualified health care provider (QHCP) is allowed to divulge to the exposed health care worker’s employer. 

The QHCP does not correspond directly with the exposed health care worker

They send a written opinion to the employer indicating that the exposed employee:

has been informed of the evaluation results. 

\- needs further follow-up treatment

\- whether the HBV vaccine was indicated

\- if the employee received the vaccine. 

• All other findings are confidential  

What details of the incident report should be included for a percutaneous injury

The depth of the wound

The gauge of the needle

Whether the fluid was injected

Is the incidence of occupational exposures is reduced if the clinician is exprienced

No, there would be the same amount of occupational exposure whether the clinician is experience or not

How many injections are given during a PDL injection on multi-rooted teeth

Depends on how many roots the tooth has since it is given at each root of the particular tooth

If a patient has a history of allergic reactions to an LA containing a vasoconstrictor, then it would be

An absolute contraindication to administer

Is a vasoconstrictor an absolute contraindication of uncontrolled hyperthyroidism

Yes

How long does it take for an allergic reaction to an anesthetic to show up after dental appointment

It can sometimes take up to 2 days after an anesthetic is given for an allergic reaction to show up

What is the action of sodium chloride

It is a buffer that creates an anesthetic isotonic, balances the osmotic pressure between the anesthetic and the body tissue

The lower the pKa of an anesthetic,

The shorter or faster the onset of action

the higher the pKa of an anesthetic means

The longer or slower the onset of action

The most common clinical sign of syncope

Pollar

Know the proper treatment for mild toxic overdose.

Monitor vitals signs 

• Protect the patient 

• Give oxygen  

• Never place a tongue depressor or anything else between the teeth

List characteristics of various topical agents.

Topical anesthetics are possible allergens. 

• Tetracaine can contribute to an allergic response. 

• Lidocaine may contain preservatives such as the parabens that could induce an allergic response. 

• Benzocaine is a commonly used ester topical that can contribute to an allergic reaction

List cardiovascular signs of toxicity of a local anesthetic.    

Cardiotoxicity in pregnancy

Cardiac dysrhythmias

Myocardial depression

List causes of pain during injection

Depositing too fast

Dull or barbed needle

Inserting too quickly

Contacting the actual nerve

List cardiovascular signs of toxicity of a local anesthetic.    

Keeping the needle cap (sheath) on the needle before and immediately after injection.

• If needle contacts anything other than the tissue, discard needle for a new one.

• Swab injection site with an alcohol-based mouthwash   

• Store anesthetic cartridges at room temperature

• Do not use damaged cartridges

List proper patient chart documentation for any local complications that may occur.  

When and why the complication occurred 

• Type of complication 

• Patient’s response to complication 

• Appropriate home care instructions if indicated

Know which dental procedures are helped when nitrous oxide is used.

SRP & scaling 

• Injections

• Patients who have a gag reflex 

• Taking of impressions

• Taking of radiographs  

• All procedures when patient has __mild to moderate dental phobia__

List characteristics of Nitrous.

Contained in a blue tank

• Colorless 

• Odorless 

• Nonflammable 

• Combustible 

• Nonallergenic 

• Least potent of all gases 

• Depresses the central nervous system to provide conscious sedation

Know why the PSA may be needed in some children.

The thick zygomatic process may overlie the buccal roots of the second primary and first permanent molars preventing a successful infiltration.

Know the agent used for the reversal of soft tissue anesthesia when a vasoconstrictor has been used

Phentolamine mesylate ORAVARSE

List characteristics of 3% Mepivacaine.

Provides short, approx. 30 minute pulpal anesthesia. 

• __Makes it easier to reach or exceed MRD than 2% Lidocaine 1:100,000 epi__ 

• Provides similar duration of soft tissue anesthesia as 2% Lidocaine 1:100,000 epi 

• Contains 50% more local anesthetic in a cartridge than 2% Lidocaine 1:100,000 epi 

• Also used when a vasoconstrictor is not appropriate  

Which mandibular supplemental injections enter the alveolar bone

Periodontal ligament

Intraosseous; uses a pecking motion into the bone

Intraseptal

Know if numbness or tingling of the lower lip is a good indication that anesthesia has occurred.

Yes, it is a good indication of anesthesia, but NOT a reliable indication of the depth of anesthesia.

• It is an indicator, though, that the inferior alveolar nerve has been initially anesthetized.

Where is the location of the injection site when there is a double inferior alveolar canal

the injection is deposited more inferiorly

which quadrants would be anesthetized first if administering injections for the left quadrants in private practice when one hour is allotted for the appointment

Left IA, long buccal, PSA, MSA and ASA

Which allows time for the mandibular arch to become completely anesthetized, slow deposition

Which maxillary sextants are often first involved in perio disease

Maxillary molars

List strategies for when a clinician encounters exostosis.

Keep the needle parallel to the bone

Move the needle injection site more superior

Move the needle injection site more superior

Increase retraction

DO NOT USE PALATAL INJECTIONS since they dont provide anesthesia

List acceptable fulcrums when administering local anesthesia.

First, a fulcrum must always be used

• If unable to fulcrum with your fingers, __arm-to-body support is acceptable__

• Extraoral fulcrums are acceptable  

• Use of stable fulcrums on other fingers and thumbs are acceptable

• __Never use the patient’s arm to rest the syringe-holding arm.  Any sudden movement of the patient’s arm may cause injury to the patient or dental hygienist.__  

  List reasons why slow depositing of the anesthetic is so important.

It improves patient comfort  

• It prevents tearing of the tissue.  When too much too fast is given, the solution doesn’t have enough time to absorb into the tissue, so it balloons up thereby tearing the tissue.

• It is a safety factor  

List reasons the pterygoid venous plexus is an area of concern when administering the PSA.  

It is a highly vascular area. There is a potential for side effects associated with intravascular injections

It is not that it is so far away, the concern is that it is very easy to accidentally run into many blood vessels created undesired effects

How many degrees a syringe should be rotated when aspirating a second time and why

Rotate 45 degrees and aspirate a second time to ensure the needle is not within a blood vessel and possibly abutting the blood vessel wall

Describe the common mistake beginners make when first learning to give local anesthesia __if they do not have a solid fulcrum.__  

Over exaggerating the pulling back motion of the thumb ring (negative pressure) which in turn pulls the needle away from the proper depth of penetration.  

Define negative aspiration.  

A clear air bubble entering the cartridge; or no return, after negative pressure is applied by pulling back on the thumb ring causing retraction of the rubber stopper. No blood is in the cartridge after negative aspiration.

Which nerve supplies the second and third maxillary molars

PSA nerve

What is the first division of the sensory root of the trigeminal nerve

ophthalmic

Which nerve provides sensory information for the teeth and associated tissue

V cranial nerve

Trigeminal nerve

Fifth cranial nerve

Which opening is located between apices of the mandibular first and second premolars

Mental foramen

Know if there are many absolute contraindications in the administrations of vasoconstrictors.

No, there are few health conditions which are absolute contraindications.  Most are relative contraindications. 

• Patients with uncontrolled systemic disease are not usually seen for SRP.

 Describe ‘Malignant Hyperthermia’

An inherited syndrome triggered by exposure to certain rugs used for general anesthesia and the __neuromuscular blocking agent succinylcholine__.   

List ways to reduce a dental patient’s level of anxiety about dental treatment.

Telephone the patient after treatment to relay a message of caring and concern.

• Consider appointment length and time of day  

• Give adequate pain control during treatment and after the procedure 

• Consider giving the patient Nitrous Oxide 

• Speak calmly and honestly to the patient  

\
65\.  List reasons for the collection of preanesthetic data of the health history.  

Need for a medical consultation 

• Modification of the dental care plan 

• Appropriateness of giving a local anesthetic or a vasoconstrictor.  

Know the different forms of Oraqix and the maximum dose per appointment.

 At room temperature: it is a liquid in the cartridge 

• At body temperature in the pocket:  it is in gel form  

• The maximum dose per appointment is 5 cartridges

Possible adverse effects of topical anesthetics

Tissue sloughing

Tissue discoloration

Possible stinging at the application site

How much topical should be placed on a cotton tip applicator for patient to recieve desired effect

only a small amount

An excess amount mixes with saliva and may numbe the tongue, soft palate or pharynx which patient doesn’t like

Explain why a 4% anesthetic plain or with a 4% anesthetic w/epi  1:200,000 vasoconstrictor would be the safest for cardiovascular patients.

The anesthetics offered in a 4% would be articaine or prilocaine.  Both anesthetics are metabolized in multiple places rather than just the liver, so they do not stay in the body as long as a 2% anesthetic.  A 1:200,000 vasoconstrictor would be the most dilute amount of vaso a cardiovascular patient should have.  This patient could have up to 4 cartridges.  

• All of the above would be safer than a 2% Lidocaine w/epi 1:100,000.

What is the side effect of epinephrine into local anesthetic solutions

There is an increase rate and force of heart contractions

List benefits of adding vasoconstrictors to a local anesthetic solution.

It prolongs the duration of anesthesia

• It reduces the possibility of systemic toxicity

• It provides hemostasis at the injection site  

Know the importance of the intermediate chain.

THE PART OF THE CHEMICAL STRUCTURE OF A LOCAL ANESTHETIC THAT DETERMINES THE PATTERN OF BIOTRANSFORMATION OF AN ANESTHETIC

DETERMINES WHETHER ITS AN ESTER OR AMIDE

Know the distribution of local anesthetics throughout the body.

After absorption into the bloodstream, local anesthetics are distributed throughout the entire body. 

• Highly vascular organs such as the brain, heart, liver, kidneys, and lungs have higher concentrations of anesthetic.

The hydrophilic amino group renders the local anesthetic molecule

Water soluble

The lipophilic aromatic ring renders the local anesthetic molecule

Lipid soluble

Concentration gradient

The relationship between relative amounts of ions inside and outside the nerve membrane

What is an axon composed of

Made of cytoplasm or axoplasm

What is an axon surrounded by

A multilayer lipid membrane

What local anesthetic drugs mainly inhibit along a nerve fiber

They inhibit the sodium influx through sodium-specific ion channels in the neuron cell membrane

Define membrane potential.

The difference between the electrical charge (or voltage) on the outside of the cell and that on the inside of the cell is called the membrane potential.  

MOTOR

The cell body participates in impulse conduction and is located at the terminal arborization. They conduct signals away from the brain or spinal cord and are called EFFERENT NERVES

SENSORY

The cell body does not participate in nerve conduction and therefore is located off the axon. They conduct signals toward the brain and spinal cord and are called afferent nerves

Know the closest anatomical landmark to the mandibular foramen.

Coronoid notch

which strength of anesthetic should never be given to the IA.

Any 4% anesthetic with or without a vasoconstrictor because it is so strong it can possibly cause paresthesia if accidentally deposited in the parotid gland.  

True Mandibular Block’.

Gow-Gates because it given high enough that it anesthetizes everything an IA does plus a few more. 

Name some issues to consider when administering the PSA injection:  

• __The skull size of the patient__ 

• The extent of paresthesia produced (How many molars does the patient have?) 

• The possibility of a hematoma formation in 10 – 14 days 

• __Do not give to a patient with hemophilia due to highly vascular area__

• Very High success rate – greater than 95% 

• Can give one injection to numb 3 teeth instead of 3 infiltrations at 1/3 cartridge each  

• __A short 20mm needle helps minimize a hematoma__

The side effects of methemoglobinemia

Brownish blood

Blue skin tone, nail beds and lips

Know the immediate procedure after giving an IA.

Wait 20 seconds then seat the patient upright for 3-5minutes

are there opioids vasoconstrictor contraindications

It is a relative contraindications for anesthetic, weigh the risks and benefits carefully

amphetamine contraindications for vasoconstrictors

**Do not** want to administer as vasoconstrictor to patient who has taken any amphetamines a couple of hours before an SRP.  The uppers are already making the heart race fast and adding epi to it will cause it to race even faster….possibly to a dangerous level.

How many mg of vasoconstrictor is in 1:50,000

.02x1.8=0.0036mg

How many mg of vasoconstrictor is in 1:100,000

.01 x 1.8mg= 0.018mg MOST USED

How many mg of vasoconstrictor is in 1:200,000

.005 x 1.8 =0.009mg

Know in which phase the primary effects of local anesthetics occur.

Depolarization