METHODS: Three databases were searched to identify randomized clinical trials (RCTs) published up until September 2017. Retrieved RCTs were evaluated using the revised Cochrane Risk of Bias Tool. The primary efficacy outcome of interest was the success rate of IANB anesthesia. Meta-analytic estimates (risk ratio [RR] with 95% confidence intervals [CIs]) performed using a random effects model and publication bias determined using funnel plot analysis were assessed. Random errors were evaluated with trial sequential analyses, and the quality of evidence was appraised using a Grading of Recommendations, Assessment, Development and Evaluation approach.

RESULTS: Thirteen RCTs (N = 1034) were included. Eight studies had low risk of bias. Statistical analysis of good-quality RCTs showed a significant beneficial effect of any NSAID in increasing the anesthetic success of IANBs compared with placebo (RR = 1.92; 95% CI, 1.55-2.38). Subgroup analyses showed a similar beneficial effect for ibuprofen, diclofenac, and ketorolac (RR = 1.83 [95% CI, 1.43-2.35], RR = 2.56 [95% CI, 1.46-4.50], and RR = 2.07 [95% CI, 1.47-2.90], respectively). Dose-dependent ibuprofen >400 mg/d (RR = 1.85; 95% CI, 1.39-2.45) was shown to be effective; however, ibuprofen ≤400 mg/d showed no association (RR = 1.78; 95% CI, 0.90-3.55). TSA confirmed conclusive evidence for a beneficial effect of NSAIDs for IANB premedication. The Grading of Recommendations, Assessment, Development and Evaluation approach did not reveal any concerns regarding the quality of the results.