This investigation evaluated the use and efficacy of
prilocaine HCl (4% plain
Citanest) for minimizing
pain associated with the intraoral administration of
local anesthesia. Clinical anecdotes support the hypothesis that
prilocaine without a
vasoconstrictor reduces
pain during injection. To determine relative injection discomfort, use of 4% plain
prilocaine was compared with use of 2%
lidocaine with 1:100,000
epinephrine and 2%
mepivacaine with 1:20,000
levonordefrin. Prior to routine endodontic procedures, 150 adult patients received 0.3 to 1.8 mL of
local anesthetic via the same gauge needle without the use of a topical
local anesthetic. Injection methods included buccal infiltration, labial infiltration, palatal infiltration, and inferior alveolar nerve block. Following each injection, patients were asked to describe the level of discomfort by scoring on a visual analog scale of 1 to 10, where 1 = painless and 10 = severe
pain. Analyses via 2-way analysis of variance revealed no interaction between
anesthetic and site of injection. However, there were statistically significant differences among the injection sites. Post hoc analysis revealed that
prilocaine was associated with significantly less pain perception when compared to
mepivacaine and
lidocaine. These results suggest that differences in initial pain perception during transmucosal injection may be a function of the
local anesthetic use, and
prilocaine can produce less discomfort than the others tested.