Assessing the Efficacy of Buffered vs. Nonbuffered Lidocaine in Dental Extractions: A Double-Blinded Randomized Controlled Trial

Background Injections using buffered lidocaine may decrease discomfort, have a quicker onset, and be a more efficacious local anesthetic. Previous studies have been inconclusive in the oral context. Purpose To address if bicarbonate buffered 2% lidocaine can decrease pain from the use of local anesthesia, has a quicker onset time, and is more efficacious. Study Design The design was a single center double blinded randomized control trial, set in an outpatient oral and maxillofacial clinic housed in the University of Cincinnati Medical Center. Inclusion criteria for the study were patients requiring a single tooth extraction due either to caries or periodontal disease. Predictor variable The predictor variable was the local anesthetic used, either non-buffered 2 lidocaine (control) or bicarbonate buffered 2% lidocaine with 1:100,000 epinephrine (study) was randomly assigned. Main outcome variables Primary outcome variables were injection pain score, and post-operative pain, time to anesthetic onset, and the number of rounds of injections required to achieve adequate anesthesia. Covariates The covariates were jaw involved, age, sex, and race, American Society of Anesthesiologists score (ASA), body mass index (BMI), current tobacco use, history of psychiatric illness, chronic pain, and preoperative pain score. Analyses Test statistics were calculated using Wilcoxon rank-sum test, Kruskal-Wallis test, Spearman rank correlation test, chi-squared test for bivariate analyses, and Fisher’s exact test. P values ≤.05 were considered statistically significant. Results The final sample was 114 subjects. The mean age of the sample was 42.97 years, standard deviation (SD) ±13.43 years. The sample was 39.47% male. The racial demographics were Caucasian (62.28%) and African American (33.33%). Buffered lidocaine did not have a statistically significant relationship with any of the outcomes. The jaw involved had a statistically significant association to the injection pain score (p-value =0.006), and the number of rounds of anesthetic required (p-value = 0.047). Age showed a statistically significant association to injection pain score (p-value = 0.032), and the number of rounds of anesthetic required (p-value = 0.027). Lastly pre-operative pain had a statistically significant relationship with injection pain score (p-value = <0.001). Conclusions and Relevance In this study, bicarbonate buffered lidocaine did not exhibit any discernible advantages over non-buffered lidocaine for any study outcomes.