Tetracaine Anesthetic Paste Showing Promise as Local Anesthetic

Tetracaine for ophthalmic use

This is an interesting study, but pulpal anesthesia?

A topical anesthetic with tetracaine numbed subjects' pulps better than benzocaine in a study reported here at the American Association for Dental Research 2012 Annual Meeting.

A new topical anesthetic is needed because what's already available doesn't work very well, said Bradley Carn, a fourth-year dental student at Southern Illinois University in Carbondale.

Benzocaine has not been shown to be more effective than placebo, and the US Food and Drug Administration has expressed concern about compounded anesthetics.

A team of dentists and pharmacists in southern Illinois has developed a formulation of 6% tetracaine, an ester-type anesthetic also known as amethocaine, pontocaine, and dicaine.

They combine the tetracaine with propylene glycol as a penetration enhancer and a plasticized base as a mucoadhesive. The resulting compound they call tetracaine anesthetic paste (TAP).

"Currently it's being used in select dental offices," said Carn. "Those clinicians are reporting anecdotal evidence that it's giving 45 to 90 minutes of soft tissue anesthesia. They are using it to cut off crowns and for scaling and root planing and gingivectomy."

In one preliminary study, researchers conducted a head-to-head comparison of TAP and benzocaine applied prior to a maxillary buccal infiltration and asked subjects to rate their pain. The difference was not statistically significant.

Conventional topical anesthetics have not been very good over the years. However, with a gentle, steady hand and good technique, the dentist can apply some injectable local anesthetic, wait a few minutes for tissue anesthesia and then deliver more. Articaine or Septocaine is especially good for this technique.

However, if Tetracaine or TAP proves to be efficacious, then I will certainly take a look at it.

I don't know about its use as a pulpal anesthetic though and other local anesthetics are quite easy to administer. I really don't see any indication here.