AIM: To review variables and management techniques that may affect anaesthesia failure during root canal treatment and methods of overcoming anaesthesia failure.
METHODOLOGY: The PubMed and Cochran databases were searched for evidence-based investigations regarding pain during needle insertion, pain on injection, efficacy of the anaesthetic solutions and anaesthesia techniques, and premedication.
RESULTS: Variables such as pain on injection, premedication with various types of drugs, volume of anaesthetic solutions, supplemental anaesthetic techniques, and additives to the anaesthetic solutions may influence pain perception during root canal treatment. Differences between teeth with healthy pulps versus those with irreversible pulpitis should be considered when the effects of variables are interpreted. However, there are several concerns regarding the methodology of investigations that have evaluated anaesthesia success rates.
CONCLUSION: Several variables may influence anaesthesia success rates. There are conditions that may help to predict a patient's pain during endodontic procedures. These conditions could be overcome either by employing methods such as premedication with a non-steroidal anti-inflammatory drug prior to the treatment visit or by using supplementary techniques before or during the treatment. However, investigators need to be more careful when reporting details of their studies to reduce concerns regarding their study bias.