Local anaesthesia
Local anaesthesia
The greatest challenge to most dentists when treating children is to ensure the child has a pain-free positive experience whilst carrying out efficient good quality dentistry. Guidance on choice of local anaesthetic agent is beyond the scope of this guidance, but is the subject of a Cochrane systematic review.98
Local anaesthesia (LA) is perhaps the procedure most likely to provoke anxiety but it is also key to providing pain-free dentistry. Evidence for interventions to increase acceptance of LA in children and young people is very limited.99 Use of the following techniques might help children accept local anaesthetic and ensure a stress-free experience for the child, parent/carer and dental team.
LA is recommended for any cavity preparation that involves cutting sound dentine in both primary and permanent teeth, any endodontic management and extraction. Dentine in primary teeth is as sensitive as that of permanent teeth. LA can be used successfully in children as young as 4 years of age. While infiltrations are effective for most treatments on primary teeth, including extractions, for mandibular primary molars an IDB injection with lignocaine may be necessary.
Most children will be apprehensive about receiving LA. However, the use of “sleight of hand” techniques when giving LA may lead to “mistrust” phobias, which may be difficult to resolve at a later time. Of the behaviour management techniques described previously, distraction is the most appropriate for use while giving LA.
Distraction aims to shift the patient’s attention from a potentially unpleasant procedure such as LA to some other action. Short term distracters such as diverting attention by pulling the lip as LA is given can work well. In addition to ensuring the tissues are taut as the needle penetrates for a buccal infiltration, thereby decreasing pain, the clinician can use verbal distraction specifically directing the child’s attention to the lip, for example “You will feel me pulling your lip up to get a better look.” Verbal distraction is also useful while applying topical anaesthetic.
Consider asking the child if they want to see what you would like to use to make their tooth (and not them!) go to sleep. If they do, then show them the syringe, emphasising how fine the needle is (like a cat’s whisker), and that only a tiny part of it will go into their gum.
Image shows application of topical anaesthetic.
To reduce the discomfort of LA use:
- topical anaesthesia
- distraction
- suction to remove excess anaesthetic and to aid retraction of the tongue
- a very slow injection technique, taking at least 60 seconds for an infiltration
- intra-papillary injections prior to palatal injections (see below)
Intra-papillary injections are useful for achieving palatal or lingual anaesthesia without any discomfort. However, it does take several minutes to complete.
Apply topical anaesthesia.
Give a buccal infiltration injection adjacent to the tooth you want to anaesthetise.
Draw an imaginary line across the base of one of the interdental papilla, and drop a perpendicular down onto the line. Where the lines intersect, insert the needle horizontally, so as to pass between the teeth on either side.
Advance the needle 1-2 mm and gently inject a drop or two of LA solution. Ensure the needle remains in the correct plane and does not become obstructed on the interseptal bone or emerge from the gingivae.
Advance another 1-2 mm, and inject another drop of LA solution.
Continue to do this, while observing the palatal aspect of the mucosa in your mirror.
After blanching is seen, withdraw the needle and insert it into the blanched area on the palatal side. The child will not feel this, and the needle may then be advanced further apically, if necessary, until complete anaesthesia is achieved.
Images show a buccal infiltration injection (left) and blanching on the palatal aspect of the mucosa in a mirror (right)
The Wand® is a computerised local anaesthetic delivery system consisting of a microprocessor/drive unit that accommodates a local anaesthetic cartridge. This is linked by lightweight disposable tubing to a pen-like handle with a Luer lock needle attached. It allows a constant slow flowrate of anaesthetic solution irrespective of tissue resistance. The delivery of anaesthetic is activated by a foot control and allows two rates of flow. The slow rate is used for needle insertion to the target area. The faster rate is used once the correct location is achieved. It may be used for conventional blocks, buccal infiltrations and intra-ligamental techniques.
Image shows the Wand® instrument.
There is limited evidence that the WAND may be less painful than conventional techniques particularly when used by inexperienced clinicians. Also, as it does not look like a conventional syringe it may be useful for children who have had negative experiences with LA.100-103 However, it is slower than conventional techniques and more expensive.