As we know in the world of dentistry today implants are becoming increasingly prevalent. And while they are a great option for tooth replacement, they bring us new issues that we must deal with such as loose restorations. While with the advent of internal connections the incidence of loose implant restorations has greatly decreased, the simple fact is that even with these improved connections we can still have things come loose – and of course there are a lot of older, more problematic connections still in service.

This brings us to the following questions: Have you come across a loose implant restoration in your practice yet? If you have, did you do anything about it? If not, should you have? If you have not come across one yet, do you know what you will do when you do?

I will start off by clarifying that what I am referring to in this article is a loose implant-to-restorative complex. Meaning that the restorative component has come loose at its juncture with the implant. With this being clear, I will add that I find it hard to imagine a situation, (although I will concede it might exist in really rare situations), in which I would not want to properly re-tighten a loose implant-restorative interface. The reasons for this are simple. First, when this connection is loose, it means you have a screw moving around inside the implant fixture that is at a higher risk of breaking since it is in reality the only thing holding the restoration in place. You now have basically zero help from the implant connection.

If you are thinking it might be easier to deal with this situation after the screw breaks and the restoration comes off on its own, I will tell you that anyone who has had to retrieve a broken screw inside an implant would disagree. Think about it. If you wait, and the inside of the implant gets damaged because of the loose screw stripping the threads of the implant, or you damaged the implant while trying to retrieve a broken screw, how is that a good thing?

The other big reason to get these connections retightened is the fact that if they are loose there is going to be gross leakage around them and debris is going to collect where it can't be cleaned out. It's a simple fact.

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So if we know that the success of our implants relies on periodontal health, how can this be a good thing? Take for example this image from a case in which I removed a loose implant restoration on a patient of mine.

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As you can see, there is gross contamination present and the tissue was far from healthy. Another unfortunate aspect of this case is the fact that the only long-term solution for this patient will be a new restoration, as the previous restoring dentist designed the restoration with completely non-engaging interfaces. It appears that the internal hexes and anything to create a positive seat were completely removed from the abutments, leaving nothing at all to engage the top of the implants.

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Commenter's Profile Image Brien Harvey
March 25th, 2015
John, Great post. Speaking as someone who has retrieved more than my fare share of broken abutment screws, I agree completely that a loose prosthesis should be addressed as soon as it becomes clear that the retaining screw(s) is/are loose. And I also agree that I have never seen happy tissue under a loose prosthesis.
Commenter's Profile Image John Carson
March 25th, 2015
Thanks for the comment!
Commenter's Profile Image Dudley Beaty
March 27th, 2015
Please give any advice on how to remove a broken screw in an implant.
Commenter's Profile Image John Carson
March 28th, 2015
Hi Dudley, I am responding to this on the Spear Talk thread you started John
Commenter's Profile Image Keith Klaus
March 29th, 2015
John, You have made some great points! As a recent grad, I appreciate these practical articles on implant maintenance and restoration. When restoring cases such as this, do you prefer non-splinted restorations? My understanding is that the couple created by splinting helps to manage the occlusal forces and to act as an anti-rotational feature. I would not expect there to be a male hex on the abutment due to lack of absolute parallelism of the two implants - the splinted abutments would not seat otherwise. Am I incorrect on this? Thanks in advance! Keith
Commenter's Profile Image John R. Carson
March 29th, 2015
Thanks for the nice words Keith! You are correct that you will have seating issues of splinted screw retained restorations if the implants are not perfectly parallel (and I would argue that it would be virtually impossible, even with a guide, to make them 100% perfectly parallel even with the best guided systems there is some inherent error, even if super small, that means you are not going to be absolutely parallel and you are doing to have issues seating splinted screw retained restorations directly to implants in cases like this. When it comes to splinting any restorations while there are times to do it for sure my bias is to NOT splint stuff if I don't have to. The reason is simple the more stuff I have connected the more stuff I have to deal with if one of those things in the connected chain has an issue. Speaking of this case specifically, the patient came to me with this restoration already in place and at that time it was not loose-she hated the occlusal esthetics, but it was not loose. If memory serves this restoration was placed about 5 years ago or so. You are also correct that one idea behind splinting implant restorations like this is for anti-rotation however IMO you still want some kind of positive seat (even if you don't have an anti-rotational feature) on the implants which this restoration is lacking. If was re-designing this restoration IF I wanted them splinted and screw retained I would want one of the abutments to have a hex and ideally both to have more of a positive seat on the implants, that being said it is highly unlikely that I would splint these rather I would do 2 separate screw retained restorations with engaging and non-rotational connections. Hope this helps, John
Commenter's Profile Image Shadi Shaaban
April 10th, 2015
John, Thank you for the article and the explanation to Keith. When do u choose to have screw retained versus cement retained restoration, and do u have a personal preference.
Commenter's Profile Image John Kline
April 11th, 2015
Recently an elderly patient presented with a broken off locator abut that was holding her PUD at 11 site. She told me it had been loose but didn't think it needed my attention. The screw was flush with the implant threaded hole. I know kits are made however I first tried the following. I modified the thick end of a small microbrush to look like a small socket wrench and was able apply vertical pressure and barely engage the top of the screw. I kept rotating to loosen and I finally backed it Out. I was Happy.
Commenter's Profile Image Ralph Nicassio
April 11th, 2015
The prevalence of loose screws in implant restorations has become unacceptably high. It is time to re-think the approach that a tiny little screw can tolerate the cumulative effect of occlusal loading and torquing. There has got to be a better way.....
Commenter's Profile Image John Carson
April 11th, 2015
Shadi, there are a ton of variables that come into play foe me when I am deciding between screw retained vs cement retained. A few of the top players are I will always pick screw retained if there is not enough space to have both enough thickness in the abutment and also the crown, additionally if I have limited access for cement clean-up then I would lean towards screw retained as well. One of the biggest issues with screw retained though is you have a hole you have to fill and in most cases mask so that can be an esthetic issue as well something the patient has to come back in for if the filling falls out. Sorry I don't have a straight answer as it is really case dependent for me. John, nice thinking outside the box! Ralph, sorry you are seeing so many loose screws. As you know we have seen less of this with internal connection and on the restorations I have placed when restoring Astra implants (BTW I am not plugging Astra it is just the one I have the most experience with) I have never seen a screw come loose on a properly torqued screw in a final restoration-yes I have seen them come loose on external connection and connections like described here but so far for me that's it. This is not to say it won't happen, just have been restoring lots of them for many years and not seen one yet.