Liposome-encapsulated ropivacaine for intraoral topical anesthesia.

OBJECTIVES: This study evaluated the efficacy of liposome-encapsulated 2% ropivacaine in topical anesthesia and its influence on pulpal response.

STUDY DESIGN: Forty volunteers received the following topical formulations in the buccal fold of the maxillary lateral incisors region (bilaterally): liposome-encapsulated 2% ropivacaine gel (RL2); 20% benzocaine gel (B20); liposomal placebo gel (LP); and placebo gel (P). Formulations were kept in place for 30 minutes, during which time the teeth were electric pulp tested every 10 minutes. After this procedure, a dental needle was inserted until periosteum contact in the same site of topical application and pain was rated by a visual analog scale. Duration of soft tissue anesthesia was assessed by pinprick test.

RESULTS: RL2 and B20 showed lower pain response to needle insertion and longer soft tissue anesthesia then P and LP (P = .0003 and P < .0001, respectively); however, RL2 was not different from B20 (P > .05) regarding those parameters. None of the formulations was able to induce pulpal anesthesia.

CONCLUSION: RL2 was as effective as B20 in reducing pain during needle insertion and inducing soft tissue anesthesia; however, neither one was able to induce pulpal anesthesia after a 30-min application.