It’s an annoying fact.
At some point in your career, a patient will come to you with a loose implant crown. Don’t feel bad – this is one of the most common and persistent problems in implant dentistry.
According to The International Journal of Prosthodontics, 60% of single implant crown screws loosen within 15 years of placement. So what gives?
Let’s understand why abutment screws loosen and how to fix the dreaded issue.
First, it could be that the screw is not torqued in fully. Or, maybe the screw is broken. Even the implant itself might be broken.
But, the most common reasons? Abutment screws usually loosen because of the occlusal forces affecting the crown or because of the crown’s design.
Abutment Screw Loosening Reason 1: Off Axis Occlusal Forces
Occlusal forces are one of the most common causes affecting abutment screws.
Just as in traditional restorative dentistry, you need to pay close attention the occlusal forces. Making sure that the opposing teeth and the implant crown are contacting properly will allow you to preserve the integrity of the implant.
When the abutment screw is loose, off-axis contacts might be the culprit. Even just one added interference may cause the abutment screw to loosen.
Here’s a visual for you. Think of a wooden stake that’s driven into the dirt.
If you press on it from the side with one finger, it won’t move right away. But if you press on it with one finger multiple times a day for many years, eventually it will start to give.
Over time, the stake will wiggle and fall over.
Reason 2: Design of the Crown
If the crown design is not harmonious with the patient’s surrounding dentition, it may ending up being too wide, too narrow, or too tall.
Any or all of these design flaws could put irregular force on the crown, abutment, or implant.
What happens next? A loose abutment screw.
The crown’s design is also a very important factor in preventing screw loosening. As the treating doctor, you understand the patient’s occlusion better than anyone else.
Was there a malocclusion that led to the failure of the native tooth in the first place? Diagnosing a problem like that will help you design a crown that is compatible with the patient’s bite.
Use your lab as your partner. It’s crucial to work with them to design a restoration that will help the patient’s implant be successful.
Why We Recommend Screw-Retained Crowns Over Cement
We all hope the abutment screw holds firm forever, but since three-out-of-five will become loose at some point, you need to know how to fix the problem.
It is much easier to fix a screw-retained crown because the retrievability is much easier.
Related: Screw-Retained or Cement-Retained Zirconia Crowns?
You won’t have to cut off the crown and start all over like you would with one that is cement-retained. Drilling through a bonded ceramic crown is bad enough, but having to do it on an unstable abutment is even worse.
Locating that pesky loose abutment screw is much less stressful with a restoration that has an easy-to-find screw-access channel. All you will have to do is access the screw, re-torque it, and send the patient on their way.
Using a screw-retained crown will save you and your patient from an unnecessary headache.
We Work With All Major Implant Systems
At First Choice Dental Lab, you can trust that our parts will perform well, no matter who you choose to make your implant.
By focusing on quality materials, maintaining expert craftsmanship, and creating solid relationships with our network of dentists, we stand by our products.
Our goal is to help you work through common problems like these.
Have a question? Reach out to us.
We would be more than happy to talk through your issue.
Your Implant Experts
At First Choice Dental Lab, we pride ourselves on having over 150 years of technical experience in our implant department.
This experience, combined with our CAD/CAM technology for design and production, allows us to fabricate high-quality implant restorations. Our resume includes, but is not limited to, screw-retained crowns, custom abutments, temporary implant crowns, full-arch zirconia restorations, hybrid screw-retained dentures, and locator dentures.
If you are looking for technical help and options to make sure your patient walks out with a smile, please contact us at 866-791-7025, or complete the form below!
