Objectives: The purpose of the study was to compare children's reactions to inferior alveolar nerve injection with traditional syringe and periodontal ligament injection with a computerized device (Wand); and to assess the efficacy of the anesthesia and their reaction after treatment. Method and materials: Twenty-five children, aged 6 to 10 years, participated in the study. The contralateral primary mandibular second molars were treated in 2 separate visits with random use of either the Wand or traditional syringe injection. The pain perception levels for each step were assessed with Band Color Scale during the preparation. A Mann-Whitney U test was performed to compare the results. The patients were asked their preference of technique after the treatment. Results: When pain was measured immediately after injection, the traditional syringe was found to be more painful than injections with the Wand (P <.05). Pain scores with the Wand injections were found to be significantly (P <.05) higher than those with traditional inferior alveolar nerve injections at the end of the restoration. The overwhelming majority of patients favored the periodontal ligament injection with the Wand. Conclusion: The Wand technique provided significantly lower pain scores during the periodontal ligament injection. However, the pain scores during the treatment were significantly higher compared with the inferior alveolar nerve injections. Most of the patients stated that they preferred the periodontal ligament injection with the Wand to the traditional inferior alveolar nerve injection.