The purpose of this prospective, randomized, blinded study was to compare injection pain and postoperative pain of an apical primary X-Tip intraosseous technique to a coronal primary Stabident intraosseous technique in mandibular first molars. Using a repeated-measures design, 41 subjects randomly received 2 primary intraosseous injections at 2 separate appointments. Using a site distal to the mandibular first molar for both injections, the subjects received 1.8 mL of 2% lidocaine with 1: 100,000 epinephrine administered with the X-Tip system using an apical location in alveolar mucosa or 1.8 mL of 2% lidocaine with 1: 100,000 epinephrine administered with the Stabident system using a coronal location in attached gingiva. The pain of infiltration, perforation, needle insertion, solution deposition, mock or actual guide sleeve removal and postoperative pain were recorded on a Heft-Parker visual analogue scale (VAS) scale for the 2 intraosseous systems. The results demonstrated that the apical primary X-Tip intraosseous technique was not statistically different (P > .05) from the coronal primary Stabident technique regarding pain ratings of infiltration, perforation, needle insertion, solution deposition, mock or actual guide sleeve removal and postoperative pain (at the time subjective anesthesia wore off). However, on postoperative days 1 through 3, significantly (P < .05) more males experienced postoperative pain with the X-Tip system than with the Stabident system.