The Single Tooth Anesthesia (STA) System from Milestone Scientific is the first computer-controlled local dental Anaesthetic system where just one injection at a single tooth is all that's needed to scientifically, safely and predictably ensure single-session injection precision. It's even highly effective for multi-quadrant cases. As the dentist advanced the needle the STA system continuously measures and monitors the pressure of anaesthetic solution as it exits the needle tip. When the specific resistance of intraligamentary tissue is identified by the STA system, an audible and visible announcement is given to confirm that the periodontal ligament has been positively reached. Anaesthetic is delivered at a controlled pressure and rate.