A single-blinded randomized controlled trial among patients requiring an upper third molar extraction was performed to evaluate the anxiety degree after receiving information or not about the functioning of The Wand system. Secondarily, perceived pain and the need of re-anesthesia were assessed. Patients were randomly assigned to the experimental group (detailed explanation about The Wand) or control group (no specific information). Local anesthesia with The Wand consisted in a supraperiosteal infiltrative technique injection 1.6 mL at the buccal and 0.2 mL at the palatal side. Distinct questionnaires for assessing dental anxiety and 100-mm visual analog scales to assess pain were delivered. Demographic data, radiological parameters, operative time and type of intervention were also registered. A descriptive bivariate analysis by non-parametric tests to detect differences in anxiety, pain and re-anesthesia was performed by SPSS 22.0 (SPPS Inc. Chicago, USA). A total of 85 patients were assessed for eligibility but 17 participants were lost due to the cancellation of the visit for the surgical intervention. Finally, sixty-eight patients were included (34 participants in each group), 47 women (69.1%) and 21 men (30.9%), with an average age of 28.8 (± 9.3) years. Patients that received a detailed explanation of The Wand did not have a significant reduction of the anxiety degree and perceived pain during the anesthetic act compared to patients that received no information. The need of re-anesthesia was not related to the anxiety level but was significantly related to increasing operative time.