Children's Pain Perception and Behavioral Feedback during Local Anesthetic Injection with Four Injection Site Preparation Methods.

An effective pain control significantly contributes to an optimal dental treatment in pediatric dentistry. This study was conducted to compare children's pain perception and behavioral feedback during local anesthetic injection accompanied with counter-irritation, refrigerant, ice precooling or topical benzocaine. This study was conducted on 99 children who needed dental treatment in bilateral maxillary primary molars by local anesthesia. Subjects were randomly assigned to three groups, in which the injection site was prepared using counter-irritation in group I, ice precooling in group II, and refrigerant spray precooling in group III. In all three groups, 20% benzocaine gel was used in the injection site of opposite quadrant as a control. The perceived pain and behavioral feedback of children during injection were evaluated using the visual analogue scale (VAS) and sound, eye, and motor (SEM) indexes. Sign and Kruskal-Wallis tests were used to analyze data at a significance level of P < 0.05. The perceived pain was significantly lower when using benzocaine compared to the other three methods (P < 0.05). Behavioral feedback of children when using benzocaine was not significantly different from the counter-irritation method (P=1.00). However, behavioral feedback with counter-irritation was significantly better than precooling (P < 0.05). Counter-irritation was significantly more effective than precooling methods in reduction of pain perception and improvement of behavioral feedback (P < 0.05). The perceived pain was significantly lower when the benzocaine method was used. Behavioral feedback was significantly better with benzocaine and counter-irritation methods compared to precooling procedures.