Implant screw fracture causes

[lcmlabforum]

Interesting case thought I best share . . .

This was pt from last week, glad took a good look and noticed after second look/cleaning debris below - pt had new screw placed just Jan 2022


Fortunately, I took pictures in Jan 2022 also . . . and pt not upset once he saw this because he also knows I insist on ordering original implant manufacturer parts.


Maybe Darwin or some others working with manufacturers can chime in - Quality control issue or design flaw?
LCM

 

[npdynamite]

Can't necessarily tell what might have caused this from the pictures, but here are the first questions I would be asking. Was it properly torqued? Was the screw ever previously brought up to torque? Do you have a radiograph to confirm that it was fully seated? Is the packaging you took the picture above that of the part? If so I would guess its 3rd party? Are you certain that the screw the exact right one for the part? If 3rd party screw seats can be designed differently. If all of those are answered and everything looks good then I would guess it was a faulty screw.

Also, can't tell from the picture, is the octagon on the abutment deformed? If so that could indicate it was loose for some time before breaking, which would point to torque. It could also mean that the design was slightly off and the doctor forced it rather than making a phone call and that could be a cause, that would be my least likely guess though

 

[millennium]

Looks like the gingiva grew over the interface which could have prevented the screw from being torqued to manufacturers specs.

 

[lcmlabforum]

Can't necessarily tell what might have caused this from the pictures, but here are the first questions I would be asking. Was it properly torqued? Was the screw ever previously brought up to torque? Do you have a radiograph to confirm that it was fully seated? Is the packaging you took the picture above that of the part? If so I would guess its 3rd party? Are you certain that the screw the exact right one for the part? If 3rd party screw seats can be designed differently. If all of those are answered and everything looks good then I would guess it was a faulty screw.

Also, can't tell from the picture, is the octagon on the abutment deformed? If so that could indicate it was loose for some time before breaking, which would point to torque. It could also mean that the design was slightly off and the doctor forced it rather than making a phone call and that could be a cause, that would be my least likely guess though

Just FYI - noticed how the new screw is hollow in the center? You don't consider it faulty?
We use torque wrench routinely and we recheck them on a fixed schedule, etc.
Don't know why you would assume it is third party when I specifically said the screw was exactly the part designed to replace the original
UCLA from the manufacturer of the implant.
And for full disclaimer, I don't force any thing on an implant being the prosthodontist who restored the implant myself.

LCM

 

[lcmlabforum]

Looks like the gingiva grew over the interface which could have prevented the screw from being torqued to manufacturers specs.

Very rarely would you find soft tiss prevent a torque wrench from going to designed Ncm. That picture was when pt showed up with
the crown in the hands so soft tiss appear to cover it.
LCM

 

[lcmlabforum]

Sorry if I was not explicit enough, but the old screw that lasted 10 years was solid at the interface.
The replacement that did not last past the first year was actually hollow at the shank.
LCM

 

[PRO ARTS DL]

I don't think they should be hollow.

You should probably notify the manufacturer and include a LOT number if you have it.

 

[doug]

Is that a Sraumann implant? Call your surgical rep and have them come take a look at it. Do not give the pieces to him, they will get lost.

 

[lcmlabforum]

I don't think they should be hollow.

You should probably notify the manufacturer and include a LOT number if you have it.

Already did, waiting to see how they will handle this.
LCM

 

[lcmlabforum]

Already did, waiting to see how they will handle this.
LCM

Is that a Sraumann implant? Call your surgical rep and have them come take a look at it. Do not give the pieces to him, they will get lost.

Nah, it's a typical clone if their WN TLI.
Won't give them unless pt consent to
submit.
LCM

 

[zero_zero]

I think the screw got loose somehow ( perhaps something was holding the crown up at the time of the placement, preventing to be fully seated )...having debris underneath would also indicate that. Eventually it started wiggling and elongating the screw to the point it broke (tensile failure)...hence the telltale circle in the middle.

 

[lcmlabforum]

I think the screw got loose somehow ( perhaps something was holding the crown up at the time of the placement, preventing to be fully seated )...having debris underneath would also indicate that. Eventually it started wiggling and elongating the screw to the point it broke (tensile failure)...hence the telltale circle in the middle.

Good theory - very familiar with concept of plastic deformation when metals are stretched beyond the elastic limit. Kind of like if you pull Jello apart, right? Actually, manufacturer was very upfront and just confirmed for me this was a design consideration they engineered into the current screws for good reasons (I am not going to divulge or disclose trade secrets type information on the web) and I accepted their explanation. As such the hole was part of the screw design and did undergo their internal testing.
So, glad to have shared that, we don;t jump to the conclusion I did should you encounter the same.
!
LCM

 

[doug]

If they shared the information with you why not pass along that information? If it's a medical device the information will be available anyway. It's easy to lookup a patent. BTW, who was the actual manufacturer? it looked like Straumann, but you said it wasn't.

 

[lcmlabforum]

If they shared the information with you why not pass along that information? If it's a medical device the information will be available anyway. It's easy to lookup a patent. BTW, who was the actual manufacturer? it looked like Straumann, but you said it wasn't.

Thanks, much as I like to, I need to respect the technical person's willingness to discuss their manufacturing and design process, etc
and need for confidential nature of what was discussed. Suffice it to say he recognized my curiosity and was very friendly to offer
the reasoning, etc at their end. I am almost sure they have people on the forum and if they want to chime in, they can certainly do that, and
confirmed, it was not the Straumann.
LCM