The Screw in my Dental Implant Has Broken Twice, What's Causing This?

The only real reason for multiple screw breakageson the same implant is poor distribution of occlusal forces. In laymans terms this means too much stress (most likley lateral) is being placed on that tooth whenyou chew.  The bite on this tooth needs to be adjusted by your dentist otherwise the implant may fail in the future

Dental implants are designed with safety factors in place.  The screw connecting the implant to the restoration is that safety factor.  If there is too much stress placed on the implant, the screw may fail, preventing further damage to the implant and surrounding supporting structures.  Since this has happened before, there may be too much stress placed on the implant.  I recommend having the implant evaluated for possible options to better distribute the forces involved.

This can be a result of several things:

1) Your bite

2) The type and size of the implant

3) The location of the implant in relation to size

If it is bite related there may be some abnormal stresses placed on the implant.  If the implant is small and is in the back of the mouth, there may be too much "load" on this implant. Finally, the type of implant may have something to do with it too.  Talk to your dentist about these factors.  

Overall, implants can be highly successful and provide a great service.

Ronald W. Konig DDS, FAGD, LVIF

Usually these fractures are due to a lot of stress on the crown itself. The best approach is to revisit your whole bit design and relieve the tension on the implant.

Most of the time when any restoration fails, be it crowns, veneers, implants it is due to your bite forces. You need to find a reconstructive dentist who has had neuro-muscular training and background.Once you'll know the cause of the bite issue, you can resolve it. Crowns, veneers, screws of implants do not loosen or come off that easily and that often if done properly  unless there is a grave occlusal issue.

All the doctors before me listed all posible reasons why your implant screw is breaking. It looks like there is a problem in biomechanical level. My suggestion is to find an implant prosthodontist ( specialist who specislizes in restoring implants) and I am sure your problem will be solved. Another hint, why don't you suggest your doctor to go from screw retained restoration to cement retained.

Good luck!

Hi

Screws break or become loose because of undesirable occlusal (bite forces). I recommend to have your team of dentist evaluate the following:

1. Your bite scheme and adjust as necessary

2. The size of crown in relation to implant diameter- Is it an oversized crown?

3. Clenching habits?- consider a night guard

4. Follow up every 3-4 months to check for any crown loosening (that is the first sign screw is getting loose and tighten before it breaks)

5. Make sure your dentist torques the screw with proper instrumentation.

Hope this is helpful

Dr. Kazemi

When an implant crown retaining screw fractures it is of concern. All of the newer style implants are designed to keep stress to a minimum on the screw. If the screw has broken twice I would have the dentist take a close look and the bite. The bite might look good  but when you move your jaw from side to side the tooth might me hitting or interfering. If the implant is an older style external hex design then it is a design problem and you might always have broken screw issues unless the implant is replaced with a newer style.

The attachment of crowns and abutments to implants is very strong.  When a screw breaks it is usually because there is excessive force being appliled to the restoration.  ... and the force is usually in a lateral direction, not straight up and down. 

This force can be caused by clenching or grinding of the teeth, or unusual habits such as nail biting, biting on pens or pencils, to name a few. I don't know if you do any of those things. ...

It could also be caused by an unusual chewing pattern or other bite issues.  I would assume that your dentist has checked for all of these things, but you must be able to reduce those destructive forces and restore a balance to the bite and the muscles  that control your jaw movements.

There are a number of reasons abutment screws break.  An abutment screw connects the abutment (part of the implant that sits above the gums) to the implant body (part of the implant under the gums).  The screw is usually made of titanium but sometimes in some systems it is gold.  There are a few implant systems that have a higher rate of screw fracture and this has to do with the engineering of the screw.  Other reasons include material fatigue, due to over stress and manufacturing defects.

If this happened in the past then this is likely due to overload of the restoration.  If there is too much stress then something has to give and its usually the weakest part of the system which luckily is this little screw.  Have your dentist check the occlusal loading of the tooth.

Hope this helps.