First experience with loose abutment/crown: best protocols?

I installed a Nobel Replace Select implant in #7 site [maxillary right lateral incisor; 12] in April 2005. I placed a crown in December 2005. Images are of implant, torqued Procera abutment, and crown. The patient did not return for follow up appointments. The patient returned when he noticed that the crown (cemented Procera) was loose. There is mobility but the crown appears solid on the abutment. I cannot move it where the margin is visible on lingual. Image with crown in place was taken today. Does not appear that anything is broken. Could the screw have loosened? If that is the case is the preferred fix to get new screw and handle it as a screw retained torque to spec and fill access. Or is there other protocols that should be followed to identify the problem–then repair. any help appreciated. Thanks.

(click image to see a larger view)

![]Images of implant, torqued abutment and today's with mobile abutment and crown](https://osseonews.nyc3.cdn.digitaloceanspaces.com/wp-content/uploads/2014/03/scan288-e1395427918292.jpg)Images of implant, torqued abutment and today’s with mobile abutment and crown

9 Comments on First experience with loose abutment/crown: best protocols?

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David Vaysleyb

3/21/2014

Very likely screw has loosened. I sincerely doubt you will the access hole because it is #7. #7 is often a 15 degree angled (not straight). Straight line access is likely through the buccal surface. -Best course of action is to section the crown and try to save the abutment (save 250 dollar abutment). Then retorque it to 30N. Then retorque it again after 5 mins. Regular impression w/cord and send it to your local lab. For the future, torque it once to 30N, then take X-ray, wait 2 mins, then torque it again. - Some doctors put flowable around the screw hole after torque to secure it in place. I personally do not.

CRS

3/21/2014

Well if the abutment and crown are loose and the implant is stable, no buccal plate loss, then it seems the crown needs to be removed by drilling and placing a new abutment, screw and crown. You could try to just place a new screw also if the crown and abutment are not damaged removing them. I would advise also checking the occlusion. I bet the screw is fractured but one can't see much on the film sorry. Since it has been nine years I would replace and charge appropriately.

3/24/2014

You nailed it Doc. Likely screw is loose. First take a template impression (for temporary purposes) and try to access the hole similar to a screw retained crown. If lingual access is available, torque to 30Ncm, place cotton pellet and cover with composite. If buccal access is present, remove crown, torque abutment, final impress and temporize. Good luck!

TAK

3/25/2014

The above comments are correct. I would like to add that I always replace the screw rather than torque the old one. Sometimes the threads become damaged and may not seat properly. If this were a posterior tooth, you would be advised to access the abutment screw by drilling an access hole through the occlusal surface. I cover all screws with a removable substance to allow future access. Composite is used to cover the access hole.

manosteel

3/25/2014

Yes the abutment screw is loose and so is the abutment. I agree with Dave the first commenter. Cut off the crown retighten the retention screw and remake the crown. We cement our crowns with temp bond, so we can pull them off and retighten the screw if necessary. If temp bond won't hold then we go to the next most retentive cement. You might want to check if the pt has any parafunctional habits, these can loosen retention screws.

Mike Heads

3/26/2014

I agree with manosteel, If you have put the crown on with temporary cement simply us the GC rubber beaked pliers and remove the crown. My concern with this case is with that amount of bone loss have you got an occlusal/overload problem causing both screw loosening and bone loss.

CRS

3/28/2014

These systems are designed to fail at the screw, it is preloaded at placement. I'm not an engineer but it would be prudent to replace the screw and not re-use it. Next time screw retained crown with implant placed accordingly so that it is retrievable. Otherwise just charge for cutting off the crown and replacing the abutment,screw and new crown. Check the occlusion nine years is great!

Dr. Omar Olalde

3/29/2014

I imagine you have tried to pull the crown out and you can't. So, cut it. Save the abutment. The screw is not broken, but buy a new one. Check the oclussion with the new crown (protrusive movement), it should'nt have any kind of contact. You have lost a lot of bone.

David Vaysleyb

4/17/2014

Ahhh good catch boys! Def replace the screw especially if its over 5 years old. Usually costs about 40-50 dollars.