1986 Screw-Vent Implant:
Dr. Niznick introduced the Screw-Vent® dental implant in grade 1 commercially pure titanium. The Screw-Vent incorporated the same thread design and diameter (3.75 mm) as the Brånemark implant, but featured a 1.5 mm-deep internal hexagon with a threaded shaft below it. This patented connection provides the stability needed between the implant and the abutment to prevent screw loosening and thus minimizes long-term prosthetic complications. It also allows screw-retained, two-piece abutments to interlock with the internal hexagon to prevent rotation, which made single tooth replacement a viable option in implant restorations. At the top of the internal hexagon, a lead-in bevel helps stabilize the abutment against lateral forces and reduces the chance of tissue being trapped in the joint, which could result in incomplete seating.