The present study was conducted to evaluate human pain perception at different phases of dental surgery using a computer controlled device, the Single Tooth Anesthesia System (STA System), versus the traditional syringe technique. One hundred healthy patients participated in this single-blind split-mouth design study. Individuals provided pain ratings at needle insertion, delivery of anesthetic solution and tooth extraction via a numeric visual rating scale or NVRS. The anterior middle superior alveolar, or AMSA, injection was compared with traditional syringe injections in maxillary quadrants. NVRS scores for AMSA were significantly lower for the STA System when compared to traditional syringe technique at needle insertion, delivery of anesthetic solution (p less than 0.0001) and also during tooth extractions (p=0.0002). A higher percentage of patients (23 percent) required a second injection after the traditional syringe technique. Subjects reported having less clinical pain with AMSA injection at every step of the dental surgery. The STA System combines an anesthetic pathway and controlled flow rate resulting in virtually imperceptible needle insertion and injection, and a rapid onset of profound anesthesia. NVRS scoring system facilitated patient comprehension in assessing pain value and intensity experienced. The two anesthetic delivery techniques were therapeutically equivalent for maxillary injections but AMSA/computer controlled protocol significantly minimizes subjective pain perception at needle insertion, anesthetic delivery and during tooth extraction.