In a dental implant assembly, there is usually a fixing of some kind for fixing, inter alia, an abutment or a spacer element to a dental implant. Typically, the fixing is a screw known as an implant screw. This implant screw is not the same as the implant per se which is itself externally threaded.
It is often desirable to have the abutment positioned at an inclined angle relative to (i.e., not coaxial with) the implant screw or implant per se. This may be of value in a number of different circumstances, however, it is especially advantageous when used in connection with dental bridges and the like. It is often desirable to design a dental bridge or superstructure with an angled implant screw channel so that, inter alia, the mouth of the channel can be on the interior or the occlusal surface of the dental bridge.
However, the provision of an inclined abutment (angulated relative to the implant screw and thereby the implant) is problematical since it makes it difficult or impossible to easily access the head of the implant screw with the usual (substantially straight) tool through the angulated abutment bore. There have been a number of attempts to try to overcome this problem.
For example, U.S. Pat. No. 6,663,388 to Straumann describes a two part dental implant comprising a straight or angular abutment which can be established by means of a base screw and a supporting ring. The abutment is provided with an inlet in the form of an axial passage. From the side of the root part, a base screw is pushed with its screw head first into the axial passage. The threaded shank of the base screw, when inserted, protrudes from the root part of the abutment. The protruding portion is intended for engagement in the axial internally threaded hole in the implant. Thus, after insertion of the base screw into the abutment, a support ring is pushed over the threaded shank of the base screw into the mouth of the inlet and is fixed in its intended position. Fixing takes place by radial welding to the lower edge of the abutment.
U.S. Pat. No. 6,848,908 to Nobel Biocare describes a dental implant arrangement, comprising a spacer element provided with a first passage having a centre line and an opening to receive a screw adapted to be fastened in an implant and being capable of receiving a screwdriver, and a second passage having an opening and a centre line along a longitudinal axis arranged at an angle with respect to a direction of screwing, the first passage being arranged at an angle relative to a direction of screwing of the first screw. The second passage is adapted to receive a second screw and a corresponding screwdriver, the second screw being there to fasten the superstructure to the spacer; wherein the centre lines angled with respect to the direction of screwing.
We provide a novel spacer element and corresponding dental implant assembly which overcomes or mitigates the disadvantages of and/or differs from the prior art assemblies.