What are the steps to treat a dental implant screw fracture?

Dental implant screw fracture on you and need a solution? A separation or fracture of the abutment screw is not a good day.  In my experience most are loose and come out easily with a piezo.  If it doesn’t move immediately with the piezo I have never gotten them out without out drilling them out. The dental code for a broken screw removal is D6096.

When the dental implant screw is loose

If the screw is loose there are many tricks you can use.

• Place a small piece or rubber band in the access, cotton, or maybe even plumbers tape to give a better grip
• Sharp explorer
• Piezo
• A ceramic veneer holder, like OptraStick, will grasp a loose screw and aid in rotating it out.
• The screw shank if there is a diagonal fracture. Azpiazu-Flores JPD 2020

Steps for dental implant screw fracture removal with piezo

1. Tap with piezo gently and see if spinning.
2. If it is spinning will usually come out pretty easily fairly quickly.
3. If not moving at all may be cold welded and not going to come out at all.

Steps for dental implant screw fracture removal with fragment fork

1. Clean area and you better have high power loupes, 4.5x or higher, and a headlight.  Check to see if thread are damaged (if damaged check steps below)
2. Place correct size Fragment Fork in slow speed and center on fragment
3. Apply force to ensure engaged
4. Reverse torque

Steps for dental implant screw fracture without anything special

1. Endo explorer, make sure it is sharp, turn the broken portion of the screw clock-wise 1/2 to 1 full turn, then counter-clockwise the same amount you turned in the screw piece in the first place.
2. Repeat this several times.
3. Do not screw in more than 1 full turn!!!
4. This will  release the bur on the screw that occurred when the screw broke. It is tedious.

References
Fragment Fork Feb 11
Dentsply kit Nergiz 2004 JPD

Salvin kit JPD 2018 Johnston
Doing it without a kit Williamson 2001 JPD

Mechanical kit without guide tube may be the fastest Panadero 2017

Fractured dental implant screw removal pdf file

1. 1/4 round bur in handpiece place a dimple in center screw
2. Place a buccal and lingual groove from center dimple
3. Form a screwdriver out of a #1 bur by cutting it with a stone.

Imam JPD 2014

1. Use fork to insert screw fragment deeper
2. Use retapping tool (Zimmer has one) Yilmaz JPD Aug 2015
3. Use fork again to try to remove now
4. Use ultrasonics as needed

How to check for internal damage after screw removal?

After a screw is out there may be internal damage if one of the methods you use can cut metal. To check this you can simply inject impression material into the implant and place a wedge of some sort into the PVS before it sets. When you remove the impression you can visually check for any obvious damage.

Checking for dental implant thread damage from screw removal by taking an impression of the implant and of a control implant or lab analog.

What to do if you can not remove the screw

There are several options for what to do if the screw fragment will not come out. First off and easiest would be to shorten an existing screw and see if that is long enough to still work. As long as a screw is 1.4mm long or 3.5 screw threads this should work. Yi JPD 2020 references 10-14 support this claim.

Implant screw cut to fit over fractured piece.

If that does not work then the next step is to retap the implant. There are special kits that implant companies make to retap the implants Carneiro JPR 2016. You would only want to retap the implant if it has a thick coronal portion.

Another option is to simply make a post and cement the post into a prepared internal aspect like Gupta 2014 JOI shows.  The picture below was an even more complicated case but the idea is the same.

As a last resort there is always implant removal.

X-ray showing how a drill through an impression analog can accurately remove a screw or post inside a dental implant that has had the internal threads damaged.