Overview of LA Techniques Flashcards
1
Q
why do we need LA
A
Number of procedures
- Dental implants
- Extractions
- Scaling
- Rubber dam placement
- Endodontics
Prevent pain during procedures
2
Q
pain
A
An unpleasant sensory and emotional experience associated with actual or potential tissue damage
3
Q
how can needle anxiety be managed
A
with technique practice
4
Q
2 main types of LA
A
amides (more common) and esters
5
Q
why are vasoconstrictors added to LA
A
Cause BV to constrict
Advantageous with LA keep LA in area for longer period of time
Control bleeding
- Help with haemostasis – scaling, subgingival restorations for crown (less interruption to placement procedure)
Prolongs for best length of time –
6
Q
what is more effective vasoconstritor?
A
Adrenaline over Felypressin
7
Q
when would felypressin be used as the vasoconstrictor in LA
A
Not as effective as adrenaline as vasoconstriction, cannot be used in pregnant
8
Q
why are preservatives added to LA
A
prolong shelf life
9
Q
risk of preservatives added to LA
A
Propylparaben – allergy risk
10
Q
why is aspiration key to LA technique
A
Adrenaline in BV need to aspirate to ensure not placed needle in BV
If in BV with adrenaline containing LA will increase HR, dangerous complication
11
Q
2 main types of LA injection
A
infiltration
nerve block
12
Q
infiltration LA injection
A
Local anaesthetic solution deposited around terminal branches of nerves
- Only get nerves situated in that area
Used to anaesthetise soft tissues
Used to produce pulpal anaesthesia where alveolar bone is thin
- Maxilla
- Lower anterior teeth
13
Q
how is pulpal anaethesia acheived
A
LA need to get through bone to achieve pulpal anaesthetise
Posterior mandible has thicker bone so infiltration not effective
14
Q
sites where LA infiltration used
A
maxilla
anterior mandible for soft tissue biopsies
15
Q
nerve block LA
A
Anaesthetic deposited beside nerve trunk
Abolishes sensation distal to site
- All terminal end fibres from nerve trunk anaesthetised
- Larger area
Used to produce soft tissue anaesthesia
Used where bone too thick to allow infiltration
- Mandible
Or working on multiple teeth and/or haemostatic worry
16
Q
anaesthesia in the maxilla for dental pulp
A
buccal infiltration
17
Q
anaesthesia in the maxilla for buccal gingivae
A
buccal infiltration
e.g rubber dam, scaling, extraction
18
Q
anaesthesia in the maxilla for palatal gingivae
A
palatal injection
19
Q
anaesthesia in the mandible for dental pulp of lower molars (and second premolars)
A
inferior alveolar nerve block (IAN/IDB)
20
Q
anaesthesia in the mandible for dental pulp of lower premolars and canine
A
mental (incisive) nerve block
- population dependent, Chinese further back in mandible effect aim and teeth effected, palpate for mental nerve
21
Q
anaesthesia in the mandible for dental pulp of lower canine and incisors
A
buccal/labial infiltration
22
Q
anaesthesia in the mandible for buccal ginigvae of lower molar and second premolar
A
(long) buccal infiltration
- additional injection to IDB
23
Q
anaesthesia in the mandible for buccal gingivae of lower first premolar and canine
A
infiltration or long buccal or mental nerve block
24
Q
anaesthesia in the mandible for buccal gingivae of lower incisors and canines
A
buccal/labial infiltration
25
anaesthesia in the mandible for lingual gingivae
secondary part of inferior alveolar end block if given
- Anterior alveolar nerve targeted initially targeted in IDB, get lingual nerve by withdrawing 2-3mm - supplies tongue on that side
- 2 nerves with one injection
Lingual infiltration
26
how to decide what tissues to anaethetise
depends on the procedure
27
what to anaesthetise when doing restoration
dental pulp
28
what to anaesthetise when doing extraction
pulp and gingivae
29
what to anaesthetise when doing scaling
pulp? or pulp and gingivae?
30
stages in LA technique
preparation of equipment
preparation of pt
injection technique
31
preparation of equipment for LA
Syringe handle and bung
Syringe barrel
- Short 25 mm for infiltration
- Long 35 mm for Inferior Alveolar Nerve Block
Cartridge
- CHECK EXPIRY DATE & BATCH – record in clinical notes, safety and traceability reasons
32
what is a short syringe barrel used for
25mm used for infiltration
33
what is a long syringe barrel used for
35mm for inferior alveolar nerve block
34
what do you need to record from LA equipment
Cartridge EXPIRY DATE & BATCH – record in clinical notes, safety and traceability reasons
35
how is LA equipment packaged
2 separate packages
- syringe handle and bung in one
- syringe barrel in another
36
ligocaine
2.2ml barrels
contains adrenaline 1:80,000
37
articaine
contains adrenaline
- 1:100,000 or 1:200,000
Increase ability to diffuse through bone
- Do not need to give IDB in lower molars potentially, may help minimise nerve damage
Not processed in liver – good or liver disease
38
citanest
Alternative - no adrenaline
No vasoconstrictor plain form as well
39
how to assemble syringe handle and bung
Slide chunkier part (finger rest) onto longer loop part (thumb)
Place bung on end
- with the thicker end towards the handle
40
how to insert the syringe barrel to the handle
Pierce non rubber seal with needle
- Gold end
- Hear plastic puncture
Blue plastic shield with clear plastic shield on top
- Safety plus needle; Single use disposable
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Take Back outer shield
- Blue end away from you
- Pull outer shield down
- Clip onto handle
- Pull away from you
- Dispose of blue tip
Outer shield clicked into handle
- Make safe by pulling outer shield down to cover the needle
```
One click – means can reuse, shield will slide back and forth
Double click – cannot reuse, locked
41
one click of outer shield over needle
means can reuse, shield will slide back and forth
42
double click of outer shield over needle
cannot reuse, locked
43
preparation of pt
Check medical history
- No contraindications
- Haemophiliac – cannot give IDB in GDP
Position in chair
- Usually dictated by the type of treatment
Dry mucosa
- Moist will dilute topical LA
Apply topical for 1-2 minutes
- Pea size on cotton wool
Atmosphere
- Tranquil - Stress will upregulate pain
- Happy place – distract from pain
Breathing
Try to be confident
- Patients can feed off your anxiety
44
injection of LA technique
Remove topical anaesthetic from mouth
Stretch mucosa
- Fingers or mirror
Puncture mucosa quickly
- (Use distraction)
Position needle tip at target point
Aspirate
- Safety plus is self-aspirating
- Pull back on plunger – active aspiration, good practice
- Metal barrels are not self-aspirating
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Inject slowly
- No less than 30 seconds
- “drip it in”
Slowly, gentle drops – like drizzle cake
Hurts for high pressure – tissue is tight
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45
needle shape
role of the bevel is to provide a cutting surface that offers little resistance to mucosa as the needle penetrates and withdraws from the tissue
- Important want to have the most advanced part of bevel away from tissue
- ---Most pointy part away
- If enters first more likely to puncture periosteum – painful
46
how should the needle enter the mucosa
Important want to have the most advanced part of bevel away from tissue
- ---Most pointy part away
- If enters first more likely to puncture periosteum – painful
47
needle position for infiltration
Bevel away from bone
If the bevel is towards the bone, the edge of needle is likely to penetrate the periosteum
Periosteal injections are more likely to evoke a painful response
48
needle position for inferior alveolar nerve block
Makes no statistical difference or clinical difference
Important want to have the most advanced part of bevel away from tissue
----Most pointy part away
49
what is aspiration
Pull block with thumb
In BV see blood in cartridge
Stop, come out, change cartridge
50
what to do if see blood in cartridge
In BV see blood in cartridge
Stop, come out, change cartridge
51
3 common myths of giving LA
Needle length influences discomfort
Needle diameter influences discomfort
(Temperature influences discomfort)
- Patients cannot detect if between 15 and 37o
52
how to identify injection site for buccal infiltration
in reflection of mucosa below apex of tooth with the mirror
53
what is infiltration anaesthesia used for (2)
Pulpal anaesthesia limited to one or two teeth
Soft tissue anaesthesia
54
2 limitations of infiltration anaesthesia
Infection
- If infection present may not be able to achieve full pulpal anaesthesia
- Some papers say push infections into space – encourage spread potentially
Dense bone
- e.g. More posterior parts of mandible
55
3 positives of infiltration LA
High success rate
Technically easy
Atraumatic
56
technique for buccal infiltration
Stretch cheek
Puncture mucosa with correct bevel of needle
- Pointiest away
Advance needle until over the apex of the tooth
If contact bone, withdraw slightly
Aspirate
- If negative inject slowly (No blood)
- If positive, reposition and repeat
Amount of LA
- Molar teeth ¾ buccal ¼ palatially
- ---2 buccal roots – can anesthetise separately or mid buccal region
Remove syringe from mouth
Slide sheath down to first click
Can replace cartridge if need further injections
- Pull black handle, glass cartridge should come with
Massage local anaesthetic into tissues
- Increases spread and desensitise other nerves in the area
Wait for 2 minutes for anaesthesia
Test
- Ask the pt
- Place probe down PDL if extraction (will damage it)
57
amount of LA for buccal infiltration of molar teeth
¾ buccal ¼ palatially
2 buccal roots – can anesthetise separately or mid buccal region
58
3 types of maxilla blocks
posterior superior alveolar nerve PSA
mesial superior alveolar nerve MSA
anterior superior alveolar nerve ASA
- different branches for different teeth
59
Posterior superior alveolar nerve block
Effective in achieving pulpal anaesthesia for the first, second and third molars
MB (mesial buccal) on first maxillary molar not reliable anaesthetised
Insert needle MB fold over maxillary 2nd molar,
Upward (45 degree to occlusal plane) , Inward (medial toward midline 45 degree angle to occlusal plane) and backward direction of needle (45 degree angle to the occlusal plane)
- needle inserted around 16mm
60
Mesial Superior Alveolar nerve block
MSAN present in only 28% of the population
MB of 1st maxillary molar, Premolars and maxillary canine
MB fold over the 2nd premolar
61
Anterior superior alveolar nerve block
Successful anaesthesia a of maxillary incisors and canine on the side of delivery
MB fold over 1st premolar target is the infraorbital foramen
62
how to dispose of LA sharps
Take everything apart - use gloves
Orange sharps bin for needle and LA cartridge if completely empty
Some LA still in need to go into the blue lidded bin
syringe handle goes to dirty room/box
- take apart and have tag with
rubber bund is in clinical waste (red stream)
63
2 LA injection performed as buccal infiltrations
mental block
buccal injection
Cross over in midline of Inferior nerve with mental nerve - may need to top up
64
mental block LA injection
Between the apices of lower premolars
Do not try to put needle in foramen
- Sore when press on
- If needle in can damage the nerve
Massage the LA
65
buccal infiltration of LA
Lower buccal gingivae
Administer slightly distal to the tooth to be treated
66
how to deliver inferior alveolar nerve block
Prepare the equipment and patient
- As for buccal infiltration, but use 35mm needle
Identify site for LA
Patient opens mouth
- Wide stretch
- Easier landmarks
- Taut tissue
67
what needle is used for IAN/IDB
longer 35mm
68
important landmarks for IDB/IAN
Coronoid notch of the mandibular ramus
Posterior border of mandible
Pterygomandibular raphe
- Skin and connective tissue makes the fauces towards
Lower premolar teeth of the opposite side
- Where barrel of needle going to go
The site of anaesthetic deposition is in the region of the mandibular foramen - aim
Right-handed to anaesthetise the right inferior alveolar nerve stand in front of pt
- Use left hand to feel coronoid notch with thumb (greatest depression on anterior ramus, in mouth)
- --- Horizontal plane is reference point to foramen
- fingers on posterior border of mandible (outside mouth)
69
right handed operator guidance for right IDB/IAN
- Use left hand to feel coronoid notch with thumb (greatest depression on anterior ramus, in mouth)
- --- Horizontal plane is reference point to foramen
- fingers on posterior border of mandible (outside mouth)
70
limitation of inferior position of IDB injection (3)
Increased onset time
Increased lingual nerve injury
No change in intravascular injection
71
coronoid notch
greatest depression on anterior aspect on ramus
| vertical plane – 6-10mmmm above teeth
72
where should the syringe barrel bne for IDB
barrel of syringe situated above premolars on opposite side
| point of puncture in raphe
73
how far should needle go in for IDB
Advance needle to contact bone
- ¾ needle in
Do not inject if no bone – too posterior
Too little of needle in – too anterior
- Replant by moving barrel to midline
Only inject if bone contacted
74
step by step inferior alveolar nerve block
Thumb placed at anterior notch
Needle entry junction of buccal pad of fat/ pterygomandibular raphe
Syringe lies over contra lateral 5-6
Advanced to bony contact (1cm of needle visible), do not inject onto retract slight
- If no bony contact reposition syringe distally
- If bony contact too soon, reposition syringe barrel mesially
When in correct position withdraw from bony contact
Aspirate
Inject slowly
- For lingual anaesthesia withdraw 2-4mm then injection of last 1/4 of solution
75
how to administer lingual anaesthesia after IDB
withdraw 2-4mm then injection of last 1/4 of solution
76
ways of confirming anaesthesia
Ask the patient how it feels
- Reassure temporary sensation
Rubbery
Numb – block in mandible, stop at midline
Tingly
Swollen/ fat
77
ways of confirming IDB/IAN
Tongue and lower lip extending to the mid-line on that side should feel different
Ability to sense pressure remain
- Confusing – pressure will remain but no pain
If carrying out an extraction or oral surgical procedure consider testing mucosa with a probe to ensure anaesthesia
