The purpose of this study was to evaluate pain perception rates in pediatric patients by comparing computerized injection device and traditional injection procedure. In a clinical trial, by using a crossover design, sixty-four patients were randomly assigned to receive, in consecutive sessions, dental anesthetic techniques with either traditional or computerized device. Visual Analogue Scale qualification and heart rate monitoring as physiologic indicator of pain response were used for the evaluation. Results showed that traditional syringe injections were more painful than computerized injection device (p<0.001). Results suggested that computerized injection device reduces pain perception compared to the traditional syringe during the dental anesthetic management.