the effect of adding fentanyl to epinephrine-containing lidocaine on the anesthesia of maxillary teeth with irreversible pulpitis: a randomized clinical trial

i ntroduction: deep and long-lasting anesthesia is essential throughout endodontic treatment. this study was conducted to compare the effect of adding fentanyl to epinephrine-containing lidocaine on depth and duration of local anesthesia in painful maxillary molars with irreversible pulpitis (irp). methods and materials: this randomized double-blind, clinical trial with parallel design was conducted on 61 healthy volunteers; the control group received a mixture of normal saline and 2% lidocaine with 1:80000 epinephrine and the experimental group received a mixture of fentanyl and 2% lidocaine with 1:80000 epinephrine. the depth and duration of pulpal anesthesia were evaluated by means of electric pulp testing in 5-min intervals during a period of 60 min. pain intensity was recorded five times: before injection, after injection, during access cavity preparation, initial file placement and pulpectomy using visual analog scale (vas). all data were analyzed and compared using the chi-square and mann-whitney tests. results: except for one patient in the control group, all others had deep and long-lasting anesthesia. the difference between pain intensity of the control and experimental groups was not statistically significant ( p >0.05). conclusion: addition of fentanyl to conventional local anesthetic solution did not increase the effectiveness of infiltration in patients diagnosed with irp.