Liposomal encapsulation improves the duration of soft tissue anesthesia but does not induce pulpal anesthesia

Franz-Montan, Michelle; Silva, André L.R.; Fraceto, Leonardo F.; Volpato, Maria C.; Paula, Eneida de; Ranali, José; Groppo, Francisco C.

doi:10.1016/j.jclinane.2010.03.001

« Previous Next »Journal of Clinical Anesthesia
Volume 22, Issue 5 , Pages 313-317, August 2010

Liposomal encapsulation improves the duration of soft tissue anesthesia but does not induce pulpal anesthesia☆

Michelle Franz-Montan, MSc (Doctoral Student)
- Department of Physiological Sciences, Piracicaba Dentistry School, State University of Campinas – UNICAMP, 13414-903 Piracicaba, São Paulo, Brazil
André L.R. Silva, MSc (Doctoral Student)
- Department of Biochemistry, Institute of Biology, State University of Campinas – UNICAMP, 13083-862 Campinas, São Paulo, Brazil
Leonardo F. Fraceto, PhD (Associate Professor)
- Department of Environmental Engineering, Julio de Mesquita Filho State University, 18087-180 Sorocaba, São Paulo, Brazil
Maria C. Volpato, PhD (Professor)
- Department of Physiological Sciences, Piracicaba Dentistry School, State University of Campinas – UNICAMP, 13414-903 Piracicaba, São Paulo, Brazil
Eneida de Paula, PhD (Associate Professor)
- Department of Biochemistry, Institute of Biology, State University of Campinas – UNICAMP, 13083-862 Campinas, São Paulo, Brazil
José Ranali, PhD (Professor)
- Department of Physiological Sciences, Piracicaba Dentistry School, State University of Campinas – UNICAMP, 13414-903 Piracicaba, São Paulo, Brazil
Francisco C. Groppo, PhD (Professor)
- Department of Physiological Sciences, Piracicaba Dentistry School, State University of Campinas – UNICAMP, 13414-903 Piracicaba, São Paulo, Brazil
- Corresponding author. CEP: 13414-903 Piracicaba, São Paulo, Brazil. Tel.: +55 19 2106 5310; fax: +55 19 2106 5218.

Received 1 May 2008; received in revised form 11 August 2009; accepted 22 March 2010. published online 14 June 2010.

Abstract

Study Objective

To compare the topical and the pulpal anesthesia efficacy of liposomal and plain benzocaine formulations.

Design

Double-blinded, randomized crossover study.

Setting

University ambulatory dental center.

Patients

30 ASA physical status I volunteers.

Interventions

Volunteers received, in three different sessions, topical application of liposome-encapsulated 10% benzocaine (LB10), 10% benzocaine gel (B10), and 20% benzocaine gel (B20) in the right maxillary canine mucobuccal fold.

Measurements

Pain associated with the needle insertion was rated by visual analog scale (VAS) and the duration of topical anesthesia was recorded. Pulpal anesthesia was evaluated using an electric pulp tester.

Main Results

VAS values (median, 1st - 3rd quartiles) were 17 cm (11 - 25), 14 cm (3 - 22), and 21 cm (9 – 21) for B10, LB10, and B20, respectively. No differences were noted among the groups (Friedman test; P = 0.58). Soft tissue anesthesia was also not different. The LB10 [10 (8 - 12) min] showed longer soft tissue anesthesia (Friedman test; P < 0.01) than the other agents [B10 = 8 (5 - 10) min, and B20 = 7 (6 - 9) min]. None of the topical benzocaine formulations tested induced pulpal anesthesia.

Conclusions

The encapsulation of benzocaine into liposome increased the duration of soft tissue anesthesia. However, it did not induce pulpal anesthesia.

Keywords: Benzocaine, Dentistry, Drug encapsulation, Injection pain, Liposome, Local anesthetic, Topical anesthesia

To access this article, please choose from the options below

☆ Supported by DFL Ind Com Ltda, Rio de Janeiro, Brazil, who supplied the the 20% benzocaine used in this study; and by a grant to Michelle Franz-Montan, MS, from the Conselho Nacional de Pesquisa – CNPq, Brasilia City, Brazil.

PII: S0952-8180(10)00100-5

doi:10.1016/j.jclinane.2010.03.001

« Previous Next »Journal of Clinical Anesthesia
Volume 22, Issue 5 , Pages 313-317, August 2010

Access this article on SciVerse ScienceDirect