Opening interproximal spaces between implants: why?

I place and restore a lot of implants in my practice. I am very conservative: I rarely do immediate loading, everything is screw-retained, I use guided surgery and cone beam x-rays for almost every case. I wait 3 months to load the mandible and 6 months on the maxilla in most cases. I use mostly Nobel Conical Connect implants. I have noticed over the years that when I have two or more implants next to each other, the final restorations are perfect at the time of delivery (contacts are firm and broad, very light occlusion, no excursive contacts, etc). But about a year later, I have noticed that a high percentage of these cases develop open contacts interproximally. Theoretically, that should not happen, but yet it happens in more than 40% of my cases where there are two or more adjacent implants. This never happens when it is a single implant next to natural dentition. Does anyone have any theories on why this is happening?

15 Comments on Opening interproximal spaces between implants: why?

New comments are currently closed for this post.
Alex Zavyalov
1/8/2016
Agree with your observation. To my mind it happens mostly on the lower jaw opposite to natural antagonists because loading mastication vectors are not usually perpendicular to an implant long axis and shifting goes mostly medially.
Carlos Boudet, DDS DICOI
1/9/2016
Can you tell us if any of these cases also develop screw or abutment loosening? I don't find this in my cases. I am wondering if it has to do with some screw retained cases. Thanks for posting.
Dr. M
1/10/2016
Thanks for your reply, 95% of my cases are screw retained and it is actually exceptionally rare for me to get a screw loosening, something that would indicate occlusal issues. This does not seem to be the case.
CRS
1/10/2016
Integrated implants don't move they are anklylosed to the bone. Could this be a prosthetic issue? Could you post some films, initial placement and when the contacts open? Perhaps a clinical photo? X-rays can be deceiving. Implants don't shift unless they have failed not a gradual process like a tooth.
Dr. M
1/10/2016
Thank you for replying. Contrary to what most people think, healthy implants can move in bone even after integrated. The movement is small and it happens less than in natural teeth. But research shows it does happen and that is what happens in many of my cases when two implants are side by side.
CRS
1/10/2016
In thirty years of placing implants I have never seen this, please post some examples.
Dr. Gerald Rudick
1/12/2016
I agree with CRS........ implants that have osseointegrated, are ankylosed to the bone...they do not move........but if any spaces are opening between implant to implant, then it is probably a prosthetic screw that has become loose. When you look at the actual size of a prosthetic crown, and the diameter of the hex retaining screw, and I will throw it the internal hex of the implant as well......there is definately an engineering mismatch of the components, that has yet to be solved......... the torque ratio of the forces result in screw loosening ....if you are lucky, or screw fracturing.....which is also not so bad, or at the worst, the wall of the implant will fracture....and the implant will have to be removed. So while our terrific field of dentistry , implantology , has made enormous strides over a relatively short time.... we still have not caught up with nature......... so if you want to keep score.....God = 100% Man 65 % .......maybe if we throw Donald J. Trump into the equation.... he will possibly make Dental Implantology Great!!!
Maite Moreno DDS, MS
1/13/2016
Seems that there is not stable occlusion to me. I stabilize most of my cases with 4 gold occlusals in the posterior. Not only porcelain and bone and stability of implants remains. Instead of priximal contacts make guide planes in the interproximal areas and then the proximal coutour of the teeth.
Tuss
1/13/2016
Hi - do you have any radiographs and photographs showing the changes over time? Thanks
Alex Zavyalov
1/14/2016
It can be detected clinically with a mylar 0.3 mm. or metal 0.1 mm. thick strip separation test between crowns. X ray is not very helpful in it.
CRS
1/15/2016
With that small of a shift I agree with Dr Rudick it is a prosthetic issue. Osteointegrated implants don't move there is no PDL it is not a tooth. The implant anklyloses to the bone. That's the biology.
Tuss
1/15/2016
Whats the age of the patients when they had the implants placed in which you have noticed the changes? Is it a youger group or across the board?
Alex Zavyalov
1/15/2016
Sometimes theory differs from practical results. Even "rigid" materials such as concrete, porcelain, metals have "flexural strength" property. As bones mostly consist of collagen tissue they have qualities of flexible and resilient material.
CRS
1/16/2016
If you look at your response the flexural strength of the porcelain and the metal abutment of the crown more likely allowed you to get the .3 or .1mm Mylar in there, not the flex in the integrated implant. I don't think this is clinically significant.
Dr. Dennis Nimchuk
4/18/2016
I have not seen the phenomenon of contacts between integrated implants with crowns opening up. However I have seen many contacts open between a natural tooth and an implant, this even when there is apparent integrity of contacts throughout the arch. This phenomenon has been reported in the literature to some extent and seems to be reported as occurring most often on the mesial side of the implant and usually in the mandible. The explanations are: that force vectors have changed, fluid hydrodynamics are to blame, micro food impaction issues develop which progressively increases the contact opening. There is no clear study which accounts for the reason. In these instances some form of revision will become necessary. If the crown is screw retained then the process becomes easier.

Featured Products

OsteoGen Bone Grafting Plug
Combines bone graft with a collagen plug to yield the easiest and most affordable way to clinically deliver bone graft for socket preservation.
CevOss Bovine Bone Graft
Make the switch to a better xenograft! High volume of interconnected pores promotes new bone. Substantially equivalent to BioOss and NuOss.