Small Bone Dehiscence from Collar of Implant Cover Screw: Next Steps?

Dr. B. asks:

I placed a dental implant in the left posterior maxilla in the first molar site [#14] following augmentation of the site with a block bone graft which I harvested from the ramus. At the time of implant placement I performed an indirect sinus lift and the patient developed a sinus perforation. I placed the patient on broad spectrum antibiotics and an antihistamine. The patient responded favorably and the implant has osseointegrated.

The patient is now 5 months following the implant surgery. There is a small buccal bony dehiscence of approximately 3x5mm which extends from the collar of the implant cover screw and distally to the mesial line angle of the second molar.

Today I gently removed some necrotic bone with a round burr so that the dehiscence is now concave, thinking that soft tissue may now be better able to spontaneously develop over a concave defect. The patient also just today informed me that from the time of implant placement, she wakes up approximately 1 day per week with a mild swelling under her left eye which resolves as the day progresses.

Thinking the patient has a chronic sinusitis, I took a panorex which failed to show anything significant. The sinus membrane is clearly visible and passes superiorly to the implant apex. The implant has bone surrounding it completely.

Clinically, the implant is stable, it is not sensitive to percussion and appears to have good soft tissue health excluding the dehisced area. What is your recommended next step? To remove any remaining necrotic bone and place patient on broad spectrum antibiotics and rinse or to restore the implant?

5 thoughts on “Small Bone Dehiscence from Collar of Implant Cover Screw: Next Steps?

  1. Hi
    1] what length of implant is covered with bone?
    2]Is the exposed area in aesthetic Zone?

    3OPTIONS :
    1] After polishing the threads of Implants like a polished Implant Collar Make a new crown to cover it.
    2]Cover the exposed area with a graft with a membrane.
    3]If clinically it is okay just polish the threads and leave it.

  2. Hi,

    I think you have your bone block not integrated. Now it is being lost, but the implant is integrated in it’s apical part.
    You have to remove all necrotizing bone and then consider polishing the implamt collar and keep it or take it out and begin again, after reevaluation of what you have already lost and how can you regenerate the tissue first.
    But don’t try to use membranes and ext, this will take you in deeper problems.
    It would be nice to have some fotos and x-rays here!

    Good luck

  3. the exposed bone should be reduced back to bleeding bone. this should be able to granulate over now with soft tissue. a ct scan will be more useful to ro sinusitis, a plane film might be inadequate. regrafting over vasularized bone under a soft tissue flap is necesary

  4. First of all Iwould use a 3D scan to see what it is the matter in de sinus. It can appear good on a 2 D x-ray, but a fistel of dehiscentie at the top of the implant isn’t always visible in a 2-D x-ray. If you have comlications you always have to think in a 3D dimension. Then you make a plan. To restore the dehiscentie at the collar of your implant I would use an Er- YAg laser. It is save to use on your implant as well as bone. You remove it till you get bleeding of your bone. The advantage with the laser is that there isn’t any smearlayer left to remove first by the body and it desinfect your bone and implant. Then I would regenerate the loss of bonewith a new graft taking in to account that after healing I need a collar of at least 1 mm of bone arround the implant. The other option is to remove the implant as a total failure and start again. But first I would start to get the ct or cbct scan to see what are the problems. The membrane isn’t visible on a x-ray. This is only be abble to see with an MRI or with endoscopes. So you can refer to your ENT for a check of the membrane site in the sinus.

  5. hi,how to handle exposed 1-1,5 implant head on facial on well integrated implants?how to do final crown restoration,margin placement in that area ?
    can i cover with regular crown exposed implant head ?

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