A partial double-blind, placebo-controlled study of electronic dental anaesthesia in children

This study was carried out to determine the effectiveness of electronic dental anaesthesia (EDA) in restorative dental treatment for children. Thirty children were allocated at random to three groups to receive either EDA, a placebo-EDA or anaesthesia by oral injection. One dentist, having introduced and administered these procedures, completed an occlusal restoration in a maxillary permanent first molar in each child. The results showed that the children changed the EDA controls in accordance with pain assessed by their reports and by their facial signs counted in video records by an observer. Both the children and the observer were 'blind' to the difference between EDA and placebo-EDA. There were no statistical differences in: (1) the number of additional oral injections required in all groups to complete treatment, (2) the depth of cavity prepared, (3) the frequency of disruptive activities, (4) the dentist's management behaviour, (5) the dentist's rating of the children's disruptiveness, (6) pain estimated by the children's reports and by facial signs. Treatment time was shortest in the oral injection group, but had no significant correlation with any measure of pain, disruptive behaviour or depth of cavity. It was concluded that EDA was no less effective than anaesthesia administered by injection but, being no more effective than a placebo-EDA, probably worked by distracting the patients.