Dental Local Anaesthesia

Equipment (in suture room)

• Disposable single use 2.2ml glass cartridges
• Single use syringe  - Septodentâ ( instruction on wall)

Local anaesthetics

1% = 1g/100ml = 10mg/ml

Lignocaine (xylocaine)

• 2% lignocaine +/- 1: 80 000 adrenaline
• Max dose 200mg or 500mg (with adrenaline)
• Rule of thumb - do not exceed > 5 dental cartridges

Prilocaine (Citanest)

• Plain or with felypressin (vasopressin)
• Use if PMHx of hypertension, IHD, hyperthyroidism, IDDM
• Contrandications - pregnant women (felypressin acts like oxytocin)
• Max dose 400mg

Bupivcaine (Marcaine)

• Long acting (8- 10 hr)
• Excellent for post operative pain control
• Slow onset (30 min)
• + Adrenaline (faster onset, same duration).

Technique

See Roberts & Hedges "Clinical procedures in emergency medicine" (in department Library)

Local infiltration

Periapical

Maxilla

• Line needle in long axis to the tooth
• Aim tip of the needle towards apex of tooth
• Inject into buccal mucosa
• Aspirate for blood
• Deposit  ~ 1ml

Mandible

For all premolars and incisors only

• Line needle in long axis to the tooth
• Aim tip of the needle towards apex of tooth
• Inject into buccal mucosa
• Aspirate for blood
• Deposit  ~ 1ml (Submucosa should swell up)

Inferior Alveolar Block

Only for mandibular teeth and soft tissues

N.B.  max doses (Rough rule of thumb - 5 cartridges max)

Complications

Local

• Spread of infection through injection into infected tissues
• Traumatic damage via pressure necrosis through rapid and forceful injection with withdrawal of bent needle tip through medial pterygoid muscle causing trismus
• Facial paresis through accidental block of the facial (VII) nerve trunk by a mandibular block being attempted too far posteriorly

Dr George Chu BDSc MBBS
Ed: Dr. Derek Louey MBBS FACEM