Assessment of the effectiveness of peripheral administration of fentanyl with lidocaine in inflamed dentoalveolar tissues

Peripheral action of opioids for pain control, for which local inflammation has been shown to be crucial, is being increasingly used in clinical practice. The aim of this study was to evaluate the hypothesis that addition of fentanyl to lidocaine, when injected into inflamed dentoalveolar tissues, can improve the quality of analgesia during surgery. Seventy-one patients reporting with pain and tenderness in the maxillary tooth were assigned into the experimental (LAF) or control (LA) group in a prospective, randomized double-blind trial. The LAF group (n = 36) was injected submucosally with a mixture of 40 microg of fentanyl (0.8 ml) and 2% lidocaine hydrochloride with 1:200000 adrenaline (2 ml). In the LA group (n = 35) 0.9% of saline (0.8 ml) was added instead of fentanyl. The pain scores were recorded before injecting, 5 min after injection, and immediately after surgery using a visual analogue scale. The mean pain scores were not significantly different at all time intervals. Twelve patients in the LAF group (2.75+/-0.72 ml) and ten patients in the LA (2.90+/-0.70 ml) group required additional local anaesthetic to achieve pain control. In conclusion, there was no improvement in quality of intraoperative analgesia on addition of fentanyl to lidocaine in inflamed dentoalveolar tissues.