New Prosthetic Restorative Features of the Ankylos Implant System
Problem: All oral implant systems rely on the abutment part of the implant to provide stability for the dental prosthetic. The Ankylos implant offers precisely machined, tapered-cone abutment (Morse taper) connection. This tapered abutment connection provides high resistance to bending and rotational torque during clinical function, which significantly reduces the possibilities of screw fracture or loosening. Purpose: This report describes the design and mechanical construction characteristics of the Ankylos implant system that make it possible for the system to provide final restorations that are natural looking, esthetically acceptable, durable, and cost effective. Methods: Review of the clinical literature. Results: The clinical results of single-tooth crowns borne on Ankylos implants in the lateral tooth region are excellent after a minimum of 5 years in function (mean = 6.3 years) compared with the high prosthetic complication rate with other systems. Abutment loosening occurred in only 1.3% of the 233 innovative implants restored with crowns that were designed with a physiologically shaped occlusal surface. Conclusion: This implant system is exceptionally well suited for use in the restoration of missing natural teeth.Abstract

(A) The innovative implant-abutment connection encourages the development of a thick layer of soft tissue around the small diameter of the implant abutment and the flat top of the implant fixture. The formation of the horizontal biological width is graphically illustrated. (B) The cone shape of the implant-abutment connection transfers horizontal forces over a wide area of the implant. The connecting abutment screw is loaded in a vertical direction only. The flat shoulder of the implant fixture supports the thick mucosal layer. (C) The 1-piece standard abutment of the Ankylos implant system. (D) The 2-piece balance abutment with a center tightening screw (zirconium oxide shown; titanium is also available). Abutment can be rotated to the desired position and fixed to that position by tightening the central screw (Note: screw rotates within a sleeve inside of the abutment and cannot be dislodged from the abutment). (E) The tapered-implant abutment connection prevents the trapping of soft tissue between the abutment and the implant, which can occur in many 2-piece flat hex implant-abutment connections (A = abutment, I = implant, H = hexagon, S = soft tissue). (F) Actual clinical case showing the interdental papillae that has formed

(A) Master laboratory cast with 2-piece balance abutment that has been modified to fit the dental arch and provide space for the development of an esthetic restoration. (B) Same clinical case as shown in (A). Note the emergence (biological width) profile evident in soft tissue and that the top of the implant is not visible because the soft tissue covers the top of the implant fixture. (C) Same clinical case from occlusal view, with abutment in place

(A) Balance posterior abutments on master laboratory cast positioned within resin index. (B) Assembled balance abutments in mouth after their relationship has been transferred from the master cast by using the resin index. The central screw has been tightened to retain the abutments in a clinically acceptable position in the mouth. (C) Completed castings in the mouth to verify accuracy-of-fit and relationship within the dental arch. (D) Completed porcelain-metal restorations. (E) Tissue response to single crown replacing natural molar tooth. (F) Another clinical case with implant restoration replacing molar after 5 years of clinical function. Note the excellent bone and soft-tissue response in both (E) and (F)

(A) Same clinical case (shown in Figure 2) from facial view. (B) Same clinical case after insertion of the final crown. (C) Same clinical case showing the interdental papillae that has formed and still remains after more than 5 years of clinical function

(A) The prefabricated SynCone abutment, which is composed of 2 cones. The bottom cone is for the tapered implant abutment connection, and the top cone is for accepting the superstructure of the prosthesis. The central screw positions the orientation of the 2 cones into a secure position. (B) Surgical placement of implants did not provide for a parallel relationship of the abutments of 2 or more implants. The angled SynCone abutment is shown on the right. (C) The alignment tools with extensions are placed on the abutments. (D) The extensions provide a visual method of assessing a common orientation. (E) The abutments are rotated until a common orientation is observed that will allow the fabrication of the final prosthesis (ie, the extensions are aligned and parallel), and the central screws are then tightened. (F) This relationship is transferred to the mouth by using resin keys as described above

(A) The alignment tools attached to orient the prefabricated SynCone abutments with a parallelometer in the laboratory. (B) The resin key is used to record the desired abutment relationships before transferring this relationship into the mouth. (C) The resin key and abutments are transferred into the mouth (this shows a fixed partial-denture resin key). (D) Clinical view of SynCone abutments after being transferred into the mouth. (E) The precision prefabricated matrices (telescopic matrices) are positioned over the abutments (they are not attached to the abutments; frictional retention retains them in their place). (F) The custom-cast splinting frame for the overdenture is cemented over the matrices. (G) Final impression with splinting frame. (H) Final clinical view of completed telescope overdenture
Contributor Notes
Paul Weigl, DMD, is an assistant professor in the Department of Prosthetic Dentistry at J. W. Goethe-University Frankfurt am Main, Theodor-Stern-Kai 7, Building #29, 60590 Frankfurt am Main, Germany.