Possible causes of a loose implant crown:
- Loose implant screw (we hope this is the case because it’s USUALLY simple to resolve)
- Broken implant screw
- Broken abutment (the part that connects the crown to the implant)
- Implant itself has loosened within the bone
- Broken fixture (implant body)
Before scheduling to assess the cause of your loose implant crown, we need documentation detailing the brand, size and type of your implant from the office that placed it. With this information, we are able to pre-order the appropriate parts and instruments to evaluate and potentially resolve the issue.
To find out why the implant crown is loose, we need to first remove the crown to assess the individual components. This entails drilling through the crown to access the screw that’s embedded within the crown. Drilling through a porcelain crown carries the risk of porcelain fracture. Often we have to guess where the screw is, since we can not see through the crown. Conventional x-rays help, but they only provide us with a two-dimensional image of a 3D object. Ideally, the screw is centered in the middle of the crown, but this can change depending on the location and orientation of the implant in the bone. Searching for the screw hole poses the risk of screw and/or crown damage, which could possibly necessitate replacement.
Once the screw has been located, we need to take it out so the crown can be removed and evaluated. If the screw is damaged or stripped, it can be difficult or impossible to remove. If this is the case, a referral to a specialist may be indicated. If the screw is just loose and not damaged, then we have two options: re-tighten the existing screw or replace the screw. Replacing the screw is far superior as a loose screw has been getting flexed and is more likely to fracture or loosen again in the future. With proper documentation from the dentist who placed the implant, we can have a new screw ready, however, because dental labs sometimes use different types of “off-brand” screws to fabricate implant crowns, it is impossible to know with 100% certainty that the parts that were ordered beforehand will be compatible. Every effort is made to identify and order the required components prior to the appointment, but because the implant was not placed by the doctor performing the repairs, there exists the possibility that these parts will not work.
Finally, there is a risk that something besides the screw is loose or broken. A broken abutment requires replacement of the abutment and crown. This will require the ordering of additional parts that are specific to your brand of implant, then taking impressions so the lab can fabricate a new abutment and crown. If the implant head itself is damaged, the implant may be useless, and would require its removal and replacement. It’s important to bear in mind all possible scenarios, risks and complications associated with loose implants and their repair.