Injectable local anaesthetic agents for dental anaesthesia

Data sources The following traditional databases were searched until January 2018; Cochrane Central Register of Controlled Trials (CENTRAL); the Cochrane Library; Issue 1, MEDLINE Ovid, Embase Ovid, CINHAL Plus and the Institute of Scientific Information (ISI) Web of Science. In addition, five more databases (IndMED, KoreaMED, Panteleimon, ANZCTR and Ingenta Connect) and bibliographies. References lists were also searched until January 2018 as well as handsearching of multiple relevant journals and potential sources of unpublished studies.Study selection All included studies were randomised controlled trials comparing different agents, different dosage or different concentration of local anaesthetics in clinical procedures or simulated scenarios using parallel or cross-over design with no language or year of publication restrictions. Data extraction and synthesis Two reviewers independently selected, reviewed and extracted data using a standardised form. Risk of bias was also assessed by two authors. Quality of the evidence was evaluated by the GRADE approach. Treatment effect was presented as odds ratios (OR) and risk ratios (RR) with 95% confidence intervals (CI) for binary data, while mean differences (MD) with 95% CI was used for continuous data. Statistical heterogeneity was calculated by the 'Q' statistic and I2. 'Summary findings' tables were created for eight comparisons. Subgroup analysis was performed based on the tissue anaesthetised.Results From the 123 studies (19,223 participants) on dental anaesthesia using commercially available formulations that met the inclusion criteria, 68 studies with 6615 participants were included for quantitative analysis. The comparison of 4% articaine, 1:100.000 adrenaline with 2% lidocaine, 1:100.000 adrenaline was reported as the main comparison and included the results of four studies with 203 participants with irreversible pulpitis during endodontic access and instrumentation. For the primary outcome of success, as measured by the absence of pain, the calculated RR of 1.60 (95% CI 1.10 to 2.32) favoured articaine with low heterogeneity. No evidence of difference was observed on pain during injection (MD 4.74 mm, 95% CI -1.98 to 11.46 mm) or following injection (MD 6.41 mm CI 95% 1.01 to 11.80 mm) based on three cross-over studies comparing the same formulations used for the evaluation of success.Conclusions The authors concluded there is no sufficient high quality evidence to determine which formulation is more effective. Four percent, 1:100,000 adrenaline was superior to lidocaine 2%, 1:100,000 epinephrine when measuring success on posterior teeth with irreversible pulpitis. Two percent lidocaine, 1:100,000 epinephrine was superior to 3% prilocaine 0.03 IU felypressin during surgical procedures and 4% prilocaine plain during surgical and periodontal treatment.