The effect of vibration on pain during local anaesthesia injections.
BACKGROUND
The "gate control" theory suggests pain can be reduced by simultaneous activation of nerve fibres that conduct non-noxious stimuli. This study investigated the effects of vibration stimuli on pain experienced during local anaesthetic injections.


METHODS
In a preliminary study, subjects were asked to rate anticipated and actual pain from regional anaesthetic injections in the oral cavity. A second study compared, within subjects, pain from injections with and without a simultaneous vibration stimulus. Both infiltration and block anaesthetic injection techniques were assessed. In each subject, two similar injections were given and with one, a vibration stimulus was randomly allocated. Injection pain was assessed by visual analogue scale and McGill pain descriptors.


RESULTS
Both infiltration and block injections were painful (mean anticipated intensity: 31.25, actual: 17.82 mm on 100 mm scale). Pain intensity with and without vibration was 12.9 mm (range 0-67) and 22.2 mm (range 0-83) respectively (p = 0.00005, paired T-test), and this effect was seen with both infiltration (p = 0.032) and block anaesthetic (p = 0.0001) injection subgroups. Furthermore, compared to no vibration-stimulus injections, injections with vibration resulted in less pain descriptors chosen (p = 0.004), and the descriptors had a lower pain rating (p = 0.001).


CONCLUSIONS
The results suggest that vibration can be used to decrease pain during dental local anaesthetic administration.
Nanitsos
E
E
Faculty of Dentistry, The University of Sydney, New South Wales.
Vartuli
R
R
Forte
A
A
Dennison
P J
PJ
Peck
C C
CC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000766:Anesthesia, Dental / Q000379:methods*; D000772:Anesthesia, Local / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007267:Injections / Q000009:adverse effects; D008297:Male; D008340:Mandibular Nerve / Q000187:drug effects; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement; D010470:Perceptual Masking; D016896:Treatment Outcome; D014732:Vibration; D055815:Young Adult
D000779:Anesthetics, Local