Exposed Metal Collar on BioHorizons Implant: Best Treatment?

Last Updated: Sep 19, 2011

Dr. M. asks:

I placed a 12mm long and 5mm diameter Biohorizons dental implant (non-laserlok) in the #30 [mandibular right first molar; 46] with two-stage approach, and covered the implant fixture with a cover screw. Then I closed the implant surgical site with a mucoperiosteal flap and 5 sutures. Everything looked good, but one (1) week later at suture removal, I could see the whole cover screw and the metal collar on the lingual side. Apparently on the lingual side the flap had failed to close completely. The patient had not experienced any pain, swelling, inflammation and there was excellent primary stability without mobility. The patient was instructed to rinse with chlorhexidine. Two months after surgery the condition is still the same. I think the implant may not have been placed deep enough. Does this need any further treatment? What kind of treatment would you recommend? Does the exposed metal collar seriously jeopardize the longevity of the implant? How should the crown margin be adjusted to compensate for this problem or should I just proceed as usual with the fabrication and insertion of the crown?

21 Comments on Exposed Metal Collar on BioHorizons Implant: Best Treatment?

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Dr. Omar Olalde

09/20/2011

Dear Dr. M, if you think the implant is not deep enough, then you should plan if you have the correct space to place the abutment and the crown. If you have not enough space, you should take out the implant and place another one deeper. If you think you have enough space for the rehabilitation, then you can do a free gingival graft from the palate before doing the restoration. Or an alloderm graft to increase the volume of the gingival tissue. I prefer to do the autologous procedure. I hope you have the training to do that or maybe send the patient to the apropiate Doctor. I don't use Biohorizons implants but you write you are using a non Laser lock implant, but you don't say if it has a polished collar or is a bone level implant. If it is a bone level implant you should do the procedure above. If it has a polished collar and it is exposed on the lingual surface and the patient has no perio problems and good hygiene I think you can do the normal rehabilitation with no modification, explaining to the patient the importance of excelent hygiene depends on him. Good luck

Kevin C. Harrison

09/20/2011

You probably sutured the flaps under tension and the flaps dehiscenced. Did you place the implant "flush, even" with the bone?

Dr. Omar Olalde

09/20/2011

As I said above, if you do a soft tissue graft surgery, you have to be very careful and have experience with that to design the flap and have enough blood supply to the graft otherwise the dehiscence would be worst. Good luck again.

Bruce GKnecht

09/20/2011

i have just started placing the Lazor Lock impalnts by Biohorizons adn there is a choice to bury the micro thread colar or not. Their claim is that the tissue will grow into the micro theads. I do not have a photo of the extent of exposure but if the impants are stable and the exposure is on the lingaul adn the impant is the Lazor Lock, you may not have a problem. Their sizes are 4.6 adn 5.8 so I do not know if you are rounding up or down. I would ask the patient if they are bothered by the metal adn if they are take them out adn redrill as soon as possible. If your gut feels that it is not right or something you would not be done on yourself. Well, you know the answer.

Kevin C. Harrison

09/20/2011

You may consider doing a soft tissue graft/augmentation to increase tissue thickness. Bone grafting around exposed implants is unpredictable.

Steven

09/20/2011

I am a little confused. The original post talks about exposed threads on the LINGUAL. Subsequent poster talks about doing a gingival graft. Huh? Where is the gingival graft being proposed?....I do hope it is not the lingual surface.

Dr. H

09/20/2011

There is insufficient information to conclude anything concrete. There are a number of ways to deal with a situation like this, ranging from things mentioned above to dealing with implant exposure by flapping the tissue and removing the microenvironments for the growth of bacteria by smoothing the exposed surface of the implant, placing the prosthetic component and preparing the abutment AND the implant body to accept a well placed accurate margin crown even if it extends to cover any implant body portion you want to the tissue (which on the lingual may not even be necessary). The idea of making snap judgements to remove an integrated implant fixture seems rash given that there is no esthetic issue. There is no reason to not attempt to alter the surface of the exposed portion of the implant as necessary to achieve prosthetic compromise. IMHO Learn to be prosthetically creative and it will save you many headaches.

Bob

03/03/2012

Thanks for your professional advise. Best so far.

John Kong

09/21/2011

Exposure of metal collar is not such a big deal. It's on a posterior tooth, the lingual side no less, so esthetics not a concern. I'm assuming the implant threads are in bone and not exposed. Then, does it make a big functional difference if the collar was flush with the bone or exposed? I don't think so. In fact you'll prob. have less crestal boneless b/c the abutment/implant interface is further away from the bone (and since biohorizons are not platform switch implants, the collar being supracrestal will prob help minimize the usual crystal boneless that occurs 1 year post loading). Just restore as usual. I don't think you need to do any gingival grafts as some people here suggested. It adds no real benefits for the patient in this case.

Nita

02/17/2021

It is now 2021 and I am reading this response and wondering if my situation is applicable. I am a patient who's about to get an implant but there is not enough bone I guess for the collar not to be exposed but in the front of the tooth it is a back molar. It's two teeth actually I have a four tooth bridge currently.because I have osteoporosis and take prolia I have been concerned about the healing process and also any possible complications like infection and whatnot.I don't know if I should go through with the implant given that I have no choice but to have the collar exposed because the kind of graft I would need doesn't stand a good chance of working I've been told and also it's quite expensive. Can someone comment on my situation.

Robert Wolanski

09/21/2011

I think it would be helpful to provide some photographs and x-rays. Seeing the cover screw is not an issue. Sometimes, especially with thin biotype tissue, there is reduces blood supply,increasing with larger (over5 mm implants) and a portion of the cover screw exposes. The metal collar may or may not be an issue depending on how much of the collar is showing and just as importantly the thickness of bone that was left over the implant (I assume there was not bone grafting)as this will determine if this problem progresses even further (assuming good plaque control) Dr. Harrison had good input. As a further consideration, look at the patients tongue function. A hyperactive and or large tongue may play a contributing roll to flap opening.

Dr. M

09/22/2011

Here is the x-ray:

Dr. Tataru

09/23/2011

Looking at the xray I believe that you did not use the Crestal Bone Drill at insertion. The neck of the implant is larger than the body so if you want the implant at bone level you should always use the Crestal Bone Drill. you will now have a very short abutment. If you can torque out the implant and introduce it to bone level you will have a far beter prosthetic situation. Good luck.

John Kong, DDS

09/23/2011

The x-ray looks acceptable to me. Dr.T, implants don't always have to be at bone level. Look at straumann's one-stage standard implants...one of the best around for posteriors and it's not a bonelevel implant. Also removing the implant at this point so you can place it more crestal in my opinion is unnecessary. Just fabricate a screw retained restoration as it needs less interocclusal space. Keep it simple.

Rob

03/03/2012

Dear Dr Kong, I do use Biohorizons Internal implants too. Wanted to know what sizes of implant do you recommend for replacement of both manidbular molars and premolars? with internal we have option of 4mm, 5mm implants and 4mm has 4.5 neck and 5 mm has 5.7 crestal neck. Is 5mm wide with 8 mm length an ideal implant for any posterior molar ? Thank you.

dr.M

09/23/2011

Agreed, the implant in not deep enough, and from begining I know that I have to use screw retained restoration, the problem is should I cover the metal collar with the restoration? or just do an usual screw retained restoration?

Dr. Omar Olalde

09/24/2011

Dear Dr. M, first I posted all the possibilities of treatments with not enough information, now that you show an X ray, a soft tissue graft is impossible or useless (that was in case of a dehiscence). The origin of everything is that the implant should be placed deeper. If you draw a line, the platform is almost at the level of gingival third of the crown of the second molar. While everybody is concernig about the periimplant health in the feauture. You should show a photograph and read about the soft tissue response over SLA surface to make a decision evidence based. But the best option would be to place it deeper, because now you are not following the protocol for that kind of implant Good luck

Felix Hartono

09/27/2011

you should not worried about the polish suface exposure, especially in the lingual area, as long as there is any sufficient keratinized gingiva, they wont be any problem. and also who would see that? so I prefer go on with the restoration. Good luck

stefano persia

09/27/2011

I totally agree with dr.kong. dont'worry about it ,for my esperiences you'll not have any further problems.

Dr. Juneja

12/22/2011

can we have a follow up of this case with the clinical pictures.Would be a good learning case. Thanks.

Richard Hughes, DDS, FAAI

03/04/2012

Don't worry about it. You can proceed with a cemented or screw retained crown, which ever floats your boat. Pay attention to occlusion. If you use a cement retained treatment, you can prep down on the implant if necessary.

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