broken screw head

A

AL1

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Have a friend that wanted me to ask if anyone heard of this problem.
Strauman implant with Altantis abutment and screw, Dr. said he torqued screw to right amount of newtons
but head of screw broke off.
Strauman says their screws are a special thread and are the only ones that should be used.
He has done lots of these cases but this is the first time he has heard of this.
Anyone else had this problem or heard of this?
 
zero_zero

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There's nothing special about the Straumann tread...ISO standard...is just usual BS to use genuine parts. I'd say was a defective ( cracked, porosity ?) screw to start with...
 
k2 Ceramic Studio

k2 Ceramic Studio

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I'm with Zero on this, reps talking BS as usual and was a duff screw or the surgeon used an adjustable torque wrench and dialed it in wrong.
 
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Hi, I have read this forum a while, but this is my first post. Great forum, I have learned a lot!
I made both upper centrals to my client about a year ago. They were Atlantis titanium abutments on Straumann bone levels. Both screws broke when doc torqued them. Screws went back to Atlantis for check up, but they did not find any faults from those.
So our conclusion was that docs torque wrench was the problem or she accidentally use it with wrong amount of newtons.(If you ask me, I would say, wrong amount of newtons.) I think doc sent that wrench for check up, but I never heard was it faulty.
 
Toothman19

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What did the doctors use to remove the broken screw? I have just recently come across this problem as well
 
dmonwaxa

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What did the doctors use to remove the broken screw? I have just recently come across this problem as well

There's a special reversal tool that can be used to back the broken portion out. They have to be extra careful not to damage the internal threads of the implant....if not they're totally screwed....new implant. Check with implant direct used to be attachments international.
 
Toothman19

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Will this still work if the screw head is broken off?
 
zero_zero

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Yup, there are tools to remove broken screw remnants, even tools to retap damaged treads...mind ya this is technique intensive...if your doc is not trained to do it, then shouldn't attempt....
 
TheLabGuy

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Some of Atlantis Abutments (small diameter ones) have a much lower torque value, this is from them.
Atlantis ( 1-800-531-3481 ) – 15Ncm (X-Small),20Ncm (Small),25Ncm (Large)
Versus the normal 30Ncm we normally see!!! Inform your Docs, hope that helps.
 
PDC

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Have a friend that wanted me to ask if anyone heard of this problem.
Strauman implant with Altantis abutment and screw, Dr. said he torqued screw to right amount of newtons
but head of screw broke off.
Strauman says their screws are a special thread and are the only ones that should be used.
He has done lots of these cases but this is the first time he has heard of this.
Anyone else had this problem or heard of this?

I gotta say that from what I see, the Straumann screws have a "beefier" head on them. I'm not taking sides here...just an observation. I'm sure Straumann screws break from time to time also...maybe not as often as the Atlantis screw does though.
 
Jo Chen

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Some of Atlantis Abutments (small diameter ones) have a much lower torque value, this is from them.
Atlantis ( 1-800-531-3481 ) – 15Ncm (X-Small),20Ncm (Small),25Ncm (Large)
Versus the normal 30Ncm we normally see!!! Inform your Docs, hope that helps.
These are torque values for Astra implants. All Atlantis abutments are torqued to the original implant manufacturers specs
 
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Rick Sonntag

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What did the doctors use to remove the broken screw? I have just recently come across this problem as well


Bigger question: how many of your doctors ASK for a new, unused clinical screw for their restorations? I'm guessing the number is very small, but if they don't ask do you still provide one? Depending on the type of case you could be torquing that screw down 10, 20, 30 times; imagine what that does to the alloy.
 
Toothman19

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That answer would be zero. They dont want to pay for it. But I may just gave to include it in my fee.

Sent from my SCH-I535 using Tapatalk
 
dmonwaxa

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Some of Atlantis Abutments (small diameter ones) have a much lower torque value, this is from them.
Atlantis ( 1-800-531-3481 ) – 15Ncm (X-Small),20Ncm (Small),25Ncm (Large)
Versus the normal 30Ncm we normally see!!! Inform your Docs, hope that helps.

Rob most of these guys have a non adjustable "fixed" torque value wrench nnnnn Der tooo cheeeep to buy more, so one size fits all. They probably aren't even aware of the various torque value requirements for the various implant abutment.
 
krashd133

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Any idea if there isa difference in the lengths of the screws/implants where the wrong system's screw could be bottoming out and cause the failure?.....just another idea for cause of failure
 
ter01475

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Understand that screws don't wear out if properly torqued. They only "deform" when over torqued... or over loaded, therefore using new screws for an abutment is a waste of money. Torque levels are determined with a mathematical formula that includes tensile strength, thread pitch, screw design, etc.. How many times have you changed out the lug nuts on your car wheels??? Never!! Torque levels provide a preload for threaded fasteners so that they don't fail from a functional load.
 
dmonwaxa

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Lug nuts and abutment screws? Thought I find some merit in some of the things stated I have to disagree overall. Comparing the two is like cs apples and oranges. Though they may have the same basic function the loads placed on them are different. Why do wheels have multiple lug nuts and not just one? Abutment screws are designed to deform when torqued, they not only elongate but the threads also deform due to compression within the thread flutes of the implant itself. Since lugnuts are designed to be reused they are engineered differently abd ms and material choices are also different. Use the same materials used for implants and use them on wheels and see what happens. Implant screws are designed to fail, ,,,,, to prevent damaging the surrounding tissue due to abnormal forces, such as impact Abnormal forces such as over torquing repeatedly and cyclic fatigue however leads to premature failure of the screw.
 
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Tom Moore

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We sell the final for $18 and both lab and final for $24. but they must buy the final or both. If they buy only the final screw the work comes back with the new final and we use our lab screw in manufacture and we keep it. Using the lab screw to finalize the implant in the mouth is not smart. It should always be a pristine new screw torqued only once. Why would a dentist take a chance on a screw that has been in the hands of others with who knows how it been treated to finalize an implant. Adding to the odds of fishing out a headless screw in the implant makes $18 worth it.
 
TheLabGuy

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Understand that screws don't wear out if properly torqued. They only "deform" when over torqued... or over loaded, therefore using new screws for an abutment is a waste of money. Torque levels are determined with a mathematical formula that includes tensile strength, thread pitch, screw design, etc.. How many times have you changed out the lug nuts on your car wheels??? Never!! Torque levels provide a preload for threaded fasteners so that they don't fail from a functional load.
Have to disagree Brother, you can easily stretch the threads of a screw and or lug nut for that matter, just ask the Nascar drivers. Metals are malleable in their composition, hence the burnishing abilities of the various metals we use in the dental field. I don't send a implant out without a new screw. As many times as we lab techs take that abutment on and off, we easily stretch those threads, especially by hand tightening some of them down as much as we do. I personally think a lot of backing out of screws, or screws getting loose over time has to do with a lot of the threads stretching and new screw not being placed during torquing. Just my take on it, feel free to convince me otherwise, I'm open any opinion.
 
ter01475

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Screws don't deform unless you overload them. When and alloy for a screw is used we know the ultimate tensile strength...means we know exactly when it will bend and deform. Torque loads never reach more than 80% of the ultimate tensile strength of the alloy....so they never are deformed by torquing. They can be deformed when the functional load...exceeds the ultimate tensile strength of the alloy....and taken further the can fail ..means fracture. As for hand tightening in the lab....if you where Hulk Hogan you might be able to achieve 12 newtons of torque by hand tightening....far from an overload.

This is a subject that I worked on back in the late 80's before torque wrenches where used in dentistry....to this day most techs have no clue about how the whole thing works...if you would like i will post the equation on how the torque loads are determine...it's sort of heavy duty for the average guy...but if you like Algebra you might enjoy it.

Even the the design of the fasteners is important...some are for bending movements....for instance the Straumann Bone Level Screw. Same thing with the seating surface....pan head vs bevel...which one would you use??? Bevel will fit better, because there is no perfect fit...therefore more surface area on the screw seat. A screw is just a simple clamp...threads vs the screw seat.

As for a race car....just going forward at high speed is increased torque on the studs, and potential for deformation...but I don't know a lot about NASCAR, but I bet they don't replace bolts on the heads every pit stop.....because they don't spin and tighten more.

If you need more information I can recommend some great books that explain the whole thing much better than i can here on this forum...I used to lecture on it...but that was a "few" years ago.

Lastly...it's nice to know I have a long lost brother out there....always thought the old man might have been up to that...but I guess I know it's all true....that was suppose to be funny!!
 

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