Higher concentration local anaesthetics causing prolonged anaesthesia. Do they? A literature review and case reports

Abstract

Higher concentration dental local anaesthetics (3% and 4%) have become more available in Australia in recent years. Benefits claimed include a faster onset of anaesthesia and improved success with injections compared to 2% solutions. Recent reports suggest that the higher concentration carries a greater risk of prolonged anaesthesia to the mandibular and particularly the lingual nerves. The literature was reviewed and those studies which demonstrated adverse effects of different concentrations of local anaesthetics were analysed. Recent cases are presented. There is an extensive international literature which confirms increased concentration of local anaesthetic does show an increased risk, by about ·6, of prolonged anaesthesia. Five case reports illustrate the impact of this complication on patients' quality of life. Careful consideration needs to be given before using higher concentration local anaesthetic agents for mandibular and lingual blocks as lower concentration local anaesthetics are safer. If acceptable to individual patients, avoidance of block injections or any local anaesthetic for minor restorative tasks could be encouraged given the severity of the complication. It is safe to use the higher concentration agents for infiltrations away from major nerves.

Assessment of alternative emergency treatments for symptomatic irreversible pulpitis: a randomized clinical trial

“…Some studies have demonstrated no evidence of injury to the nervous structure (Baroni et al 2013, Rogers et al 2014, whereas others have shown increased risk of neurotoxicity (presenting as paraesthesia) related to the use of 4% articaine for regional blocks (e.g. inferior alveolar) (Haas & Lennon 1995, Hillerup & Jensen 2006, Garisto et al 2010, Kingon et al 2011. One potential limitation of the study might be that all inferior alveolar nerve blocks were administered using 4% articaine with 1 : 100 000 epinephrine hydrochloride.…”

Contemporary exodontia

“…Most commonly local anaesthesia is the technique employed but this is not without complication. [2][3][4] The objectives of exodontia are clear cut; to remove the whole tooth whilst preserving the alveolus for future prosthetics or implants. Again it is all too easy for the inexperienced dentist and their patient to emphasise the removal of the whole tooth at the expense of the alveolus.…”

Superficial skin necrosis and neurological complications following administration of local anaesthetic: a case report

“…6 A review of the literature revealed only two similar cases occurring following administration of an inferior dental block. Torrente-Castells et al 7 reported a case involving a 10-year-old girl who received an inferior alveolar nerve block using one cartridge of 4% articaine with 1:200 000 adrenaline.…”