Guidelines for positioning external hexagon implants in screw-retained multiple prostheses using rotational abutment-type components.

Abstract

This study measured the maximum angulation between 2 implants allowed by the internal walls of the component in screw-retained multiple prostheses using rotational abutment-type components. Thirty specimens of 3 different brands (Conexão; Neodent; and SIN), consisting of titanium rotational abutments connected to external hexagon abutment analogs with standard platforms, were divided into 3 groups. The specimens were internally filled with polyester resin, screw retained, torque, and sectioned to assess the space existing between the internal wall of the rotational abutment component, edge, and vertex of the hexagon. The measurements were performed using 3-dimensional equipment. When the implant hexagons were oriented edge-to-edge, groups 1, 2, and 3 presented 40.75, 45.00, and 31.89 degrees, respectively. Vertex-to-vertex hexagon orientation showed 9.79, 18.18, and 3.27 degrees for groups 1, 2, and 3, respectively. The maximum mean angulation in the mesio/distal direction between the 2 implants with hexagon-oriented vertex-to-vertex is 10.41 degrees, and hexagon-oriented edge-to-edge is 39.54 degrees. This study suggests guidelines for positioning external hexagon implants for interference-free screw-retained multiple prostheses using rotational abutment-type components.