How do you remove this broken Ankylos abutment?

Please view this radiograph which shows an Ankylos Regular/C abutment fractured at the level of the implant platform.  I completely unscrewed the abutment screw which is still intact. I have not been successful at removing it as the broken cone portion is stuck so hard inside the implant fixture. Any suggestions for how to remove this?

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11 thoughts on “How do you remove this broken Ankylos abutment?

  1. Cut off the pin, then use a fast handpiece to remove the neck of the abutment still in place by cutting a slot in it, take care not to touch the inside of the implant. I use a fine tungsten carbide bur. It should then then prize out. The screw pin may need trimming before you can use the reversing screw remover to take out the abutment screw at the bottom of the implant. Ive done it a few times but it can be tricky.

  2. Ankylos have a specific drill tap and removal kit for this. I have had to use it in the past. Do not try and remove it otherwise as you may damage the Morse fit of the replacement abutment.

  3. This is an inherent bio mechanical problem with Ankylos captive screw abutments which should be addressed by Ankylos/Dentsply. Request the full retrieval kit from Ankylos and follow instructions. Works but technique sensitive. You have crestal bone loss. Give patient best care and remove & replace the implant save yourself long time aggro. I have given my students/ colleagues cautionary notes on this weakness in Ankylos. But if you use solid abutments it is best system on the planet.
    Good luck

    1. I have retrieved several of the fractured solid abutments as well but obviously stronger than the two piece,as there is no through bore for the screw. However, this produces a very difficult retrieval as it cannot be distracted. It either has to be unscrewed, which in my experience has been problematic, or the conus seperated from the threads and retrieved in pieces. I have done both with significant thought on evolved tooling to simplify the process with only minor progress.

  4. I have recovered many of these fractured Ankylos abutments over the last six years so I can speak from deep clinical experience. First please contact the Dentsply rep in your area for guidance as they now have a recovery kit for this clinical situation based on a distractor. This is much safer for the implant than grinding out the fractured component and sloting is a slow way to grinding it out because you start to loose the through bore walls you need to tap. As this is a two piece version, vs. a solid abutment , you should presume it to be a CX indexed version unless you know otherwise. However, the procedure remains the same. The recovery sequence is as follows: first you must clear the through bore of the retained abutment conus. This is done by either overtorquing the abutment screw to break it at the laser weld or carefully grind it down out of the way with a surgical length 56 bur taking care to avoid the conus walls and stopping at 3 mm. Once completed the through bore is enlarged to 1.25mm (.0492″). The kit has a core drill for this function. Again drilled to 3mm. The drill is laser marked at 3mm. The third step is to tap the conus with the 1.6mm tap. The tap in the kit is an aggressive starting tap which I use on a Bien Air electric torque controlled auto reversing handpiece. I “peck” tap at low rpm around 300 with auto reverse set around 3Ncm. Easy does it in this step will save a lot of time. I switch taps to a three fluted plug tap to safely pick up an extra couple of threads but this tap is not in the kit. After the threading is complete, install the distraction bolt and the distrator and rotate to lift out the conus. Many times an audible “pop” can be heard confirming how tightly stuck the conus was. Once the conus is clear the screw fragment has to be retrieved. This is clearly most often the easier part of the retrieval. If the thread basket was open if the laser weld was fractured in step one then use the red stripe tool to engage the basket counterclockwise and it will unscrew out of the implant. If the shaft of the screw is intact with the thread basket and above the threads it will be next to the implant splines. I rotate this out with a surgical length bur on the OD of the screw shaft. The bur looks like a fissureotomy bur (Schein FG 560) 102-6643. I use a Zeiss microscope for visualization and would not attempt this without. I also verify each step with the scope and avoid many complications. If you do not have a scope consider talking to your Endodontist as they generally have at least one.
    Charlie Mastrovich,DDS

    1. Hi Charlie

      Thanks very much for your detailed guidance. I have a few questions:
      1- Do you recommend to break the abutment screw by over-torquing it OR grind it out of the way? Which option is better for the later retrieval of the screw fragment?

      2- You said the “three-fluted plug tap” is not in the kit. Where do you get it? Do I really need it?

      3- This abutment is a regular C non-indexed version (I restored this case). Would this be more difficult to retrieve than the CX indexed version?

      4- How long should I book the appt? This is my first time using this distractor kit.

      5- For the replacement abutment, should I use a solid abutment instead of a two-piece? I’m concerned about the very difficult retrieval process in the event the solid abutment also fractures.

      Thanks again,
      David

      1. Hi David,
        I think it would be best if we can discuss directly as you have several questions and it will be more efficient than trying to cover all the possibilities in depth. My office number is 760 741-6650. I’m located in Escondido, CA. I generally do mechanical rescue cases on Thursday and Fridays. Talk to Debra and depending on the day I may have to arrange a time to return your call. Glad to help and share my experience.
        Charlie Mastrovich.

      2. One thing to note: Ankylos designed the threads on the abutment screw to slide off. If you don’t overtorque them into the implant body, they will come out easily and separately from the shaft and broken abutment.
        We just did another last month, but it was the broken shaft.

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