Efficacy of the Computer-Controlled Injection System STA, the Ligmaject, and the dental syringe for intraligamentary anesthesia in restorative patients

The intraligamentary or periodontal ligament (PDL) injection technique uses a standard dental syringe 1,2 and many clinicians have described several difficulties related to it. These include positioning the needle within the desired location, controlling the placement of the needle throughout the administration phase of anesthesia, increased pain perception reported by dental patients due to high syringe pressure and consequent tissue damage. Other concerns centre around the correct amount of anesthesia to be delivered, the duration of the effect of the anesthesia, and the type of anesthetic that can be injected. The STA-System (Single Tooth Anesthesia System, Milestone Scientific, Inc., Livingston, NJ) was developed in 2006 as an evolution of the Wand System and incorporated DPS (Dynamic Pressure Sensing) technology, specifically engineered for dental applications. The STA provides a continuous monitoring of real-time pressure during all phases of an injection. It can limit the maximum pressure used as well as detect a loss of pressure from leakage during an injection. Furthermore, greater anesthesia dosage can be delivered by the STA than with a conventional syringe while performing a PDL injection. The recommended dosage of anesthetic solution ranges from 0.5 mL (single tooth) to 0.9 mL (multi-rooted teeth) when using 4%concentration of articaine hydrochloride. The aim of this study was to evaluate the efficacy of the STA Intraligamentary Injection, including the duration of anesthesia and discomfort experienced during and after the injection, when compared to an Intraligmentary Efficacy of the Computer-Controlled Injection System STA, the Ligmaject, and the dental syringe for intraligamentary anesthesia in restorative patients