Circumferential Bone Loss around MIS Seven Implant: What Should I Do?

Looks great position wise for your first the small amount of bone loss could be due to the non seating of the healing collar seen by the small gap between the collar and the Implant. Hence bacteria and bone loss. Peter

Sorry re-read and you have only just placed it at 3 months , then possibly a small spontanoeus exposure or compression on torquing but x-rays difficult to see clearly. Peter

Hi Dr Yong , yes sometimes the there may be small opening in the gingiva and bacteria may lead to this situation as to torque it varies from system to system and is mostly seen in the mandible . In some systems with a micro-thread and aslightly flared head it is vital to "tap" the bone to ensure this does not happen . Peter

Dr Yong, Considering the different angles and positions of your x-rays a clear comparison of the bone to implant interface is not possible. Nite now one of the films even shows the upper molars in the lower molar PA. Using the Rinn system along with an acrylic bite plane ( or any similar system ) will help you to repeat closely the original film position. If you are not certain of good film positioning, review the standard recommendations for Mesial/Distal positioning and compare the cusp positions in your films. The wide cuspal spacing in your film shows a high angle which could make an interface dark area appear to have grown. For now, get a good repeatable x-ray positioning device and bring the patient in for a good film parallel to the long axis of the teeth and implant and lost it for us, please. John

Sorry about all of the iPad auto corrections. I do hope you'll forgive me on that and make the films parallel to the "teeth" and not the "feet"! John

How would you differentiate between "compression necrosis" and overheating of the bone in this type of situation? How would treatment modalities differ for each? I would assume, in the absence of purulent exudate, montoring the situation for bone level stability would be acceptable? At what point would one rationalize re-entry and debring site vs removal, grafting and replacing implant?

I feel the bone loss is a bacterial problem. Sometimes there may be small opening in the gingiva and bacteria enter into the healing cap area and setup an inflammation problem if the area is sub-gingival. This is much like the micro gap problem at the abutment and implant junction of many implants.

HiDear, I SEE IN THE FIRST PHOTO IT IS CLEAR YOU PUT IMPLANT IN MASIAL ROOT POSITION AND MAY BE THE EXTRACTED IS NOT LONG TIME AND THE SITUATION OF TOOTH AND ITS PERIODENTIUM REFLEX ON THE HEALING AND WE KNOW ALL ABOUT THE BONE LOSS IS FAST AND MORE IN THE FIRST MONTHS AND ABOUT TUORQUE IS MORE 30 N/CMIT IS OK AND THE STUDIES SAY AS IF MORE THAN 65 N/CM IT IS BAD BECAUSE WILL CAUSE MICROFREACTURES IN THE BONE STRUCTURE AND THE NEW STUDY TELL HOW CAN USE THE FORCE EARLIER TO ADAPTH OF BONE FOR GETTING REMODEDLING MORE MODELING I THINK THERE ARE MANY SYSTEM WHAT HAVE RACHET TELLING YOU AND TOURQUE VALUE , THANKS

do nothing, you have a microgap bone loss which is normal.

Hi Doc; Case looks ok. Just a few suggestions on your next case. It is my understanding that when I place the implant I do it with a parallel axis to the anterior (medial) tooth. 2- I like to take a bitewing PA at time of placement in order to really appreciate the bone height. 3- I work with MIS, I think the healing cap, is to big for the case. I understand you were looking for a good emergence profile, but this healing cap may have produce some pressure and swelling leading to the marginal bone loss. 4- you have a good length, I would recommend that you apply some progesive loading with a temporary abutment and resin crown and see if margins stabalizes. 5- Always advise the patient of the condition of the implant and that failure is posible. 6- Consider an "ATLANTIS" abutment, it is costly put may help the case. Cost permited. May all go well for. Till next time. mkg

I would say from the xrays that the implant should have been seated 1mm deeper. Nothing you can do now. A good personalized ceramic abutment and controls

Hello Doctor, Thank you for posting your case for your peers to critique and analyse. I place MIS SEVEN implants too, and last week I placed two immediates in the 33 and 43 areas for overdenture abutment. The MIS Surgical kit has a ratchet wrench that is recommended for final implant placement, but this ratchet wrench does not have torque control like the prosthetic torque wrench. Hence, many times a dentist ends up torqueing the implant in really hard, hoping to get primary stability, however, the high torque can cause pressure necrosis, especially at the neck and ESPECIALLY in a wide implant like the 5mm diameter. Hence, if you read Carl Misch's book, you will find he recommends to torque it down with a ratchet and then go anti-clockwise one turn and leave it there in Type 1 and 2 bone types. This way you have "threaded" the bone and the crestal bone will not be under high pressure during the healing phase. The use of the drill in the final placement makes sure you are not exceeding 35Ncm, which I hold to be the threshold. Also, I believe you could have taken it down another 1 mm. Leave the healing collar on it for another 3-4 weeks, retake the X-ray, if no more bone loss or clinical sign of inflammation, proceed for your crown, screwed or cemented. But for your first case, you are doing very well! Congratulations!

Do nothing, this minor circumferential bone lost is not unusual, just a remodeling process.

go ahead and restore it, looks good, it will be fine.

high torque causes that problem? I suggest read recent articles, not books. i.e: Clinical Outcome of Dental Implants Placed with High Insertion Torques (Up to 176 Ncm) Philippe G. Khayat, DCD, MScD;* Hélène M. Arnal, DCD, DESCB;† Bahige I. Tourbah, DCD,

Dr. JUAN: Could you site the journal for this study? Also, I am not familiar with the title DCD. Are the authors dentists? I usually use NobelActive and occasionally torque to 100+ ncm without any problem; so I am inclined toward this notion that it is not compression necrosis. MIS7 seems to have very similar threading. As Dr. Fairbairn wisely notes however, it depends on the type of implant as well as the type of bone. Dr. JONG: Could you tell us when the extraction was done? Heck of a good job on implant #1. If it were me, I'd restore now and not worry unless there is an unfavorable follow up. You could always remove then if needed.

Just go ahead and restore the thing! 1mm of crestal bone loss in the 1st yr isn't unusual. If the MIS7 has a polished collar then the recessed area within polished metal which might even be a little less plaque retentive. The Alantis abutment would be a good one but an abutment with a crown finish line 0.5mm subgingival so the margin is well above the implant-abutment interface is the important point! Unless his criterion has changed Misch advocated an insertion torque range of 25-40 Ncm. Replacing the implant at 50% verticle bone loss and 1+ mobility

Dr. Dobro, would you kindly explain what you are referring to in your comment re "implant #1"? Am I missing something? DrT

Sure. Dr Jong wrote that this was his first attempt at placing an implant. It was a milestone achievement (and better than I did on my first, a long time ago).

If you extracted the tooth and placed the implant in the same setting, did you graft the distal socket and space around the coronal aspect? I find myself having to remove bone, to access the cover screw in many cases. Regardless, it seems as if the premolar anterior to your implant has some bone loss, so this maybe as good as one could do. You also could be looking at some "cervical burnout", just as you are seeing on the posterior molar. Bv

Restore now, monitor closely Use a guide to control depth at the next implant-,this looks a bit shallow, ideally 2-3mm below expected gingival margin Plan all implant placement on soft ware first- it is so easy to utilise now. Use reduced diameter healing abutment to get increased volume of soft tissue which can be displaced later when thickened. If not thickened graft soft tissue. I agree with Atlantis type abutment to mange tissue between implant and restorative margin best however there may be a lack of space and direct screw access might be best

Did you graft this defect that you exposed? How did you manage the soft tissue? DrT

i don't see a problem with this case , because you don't have any significant bone loss. if you want to avoid different bone levels , then you have to plane the bone with a bur and leave polished collar above crest.. i use mis seven alot , its a very predictable implant.. you should be able to get a nice result . good luck

Does anyone think this bone loss could have been from overheating bone during preparation?

No, I personally do not, simply because the entire implant would have failed, in my opinion . Bv

1mm loss of bone at the crest is not that unusual. My only suggestion would be if you have good initial stability why didn't you do a one stage procedure. Reexposure of the implant and flap reflection has demonstrated to relate to about 1mm of bone perexposure incident. Restore it and move on, it's a B grade.

In response to Dr T and grafting a 1mm circumferential loss of bone, in my hands and my partners this doesn't seem to work for us. We have tried a variety of grafting materials and membranes, you got what you got.

healthy gingival seal is the key to prevent further inflammatory bone loss. implant will be fine with good hygiene and proper restoration. angle of insertion left a relative distal micro thread exposure, not a big deal. practice insertion angles and cortical taps. good start. follow the normally positioned tooth roots, not the collapsing molars! learn to make guides if this is a problem for you. good luck!

Lets say you saw this bone loss after single stage placement 6 weeks post-op. Would consensus still be "pressure necrosis"?

The Implant angulation is fine . Avoiding the Mental foramen is sensible.The 1mm bone loss is apparently uniform and no inflammation hence likely to be either you didn't fully seat the implant bone to implant originally or some bone resorption occurred .(due to a myriad of possible reasons)Restoring the implant is the next logical step. Pointing out the loss of bone height to the punter is the norm. Why not use an acrylic crown as your long term initial restoration..

Peter is correct, it most likely is due to too much stress transmitted to the crestal bone upon placement. Misch covers this in his text.

Eric, it is a pretty accepted suggestion, that some degree of bone loss occurs every time you lift the periosteum. I suggest making a small conservative incision over the cover screw and exposing just enough to place your hex driver and performing the second stage procedure. The suggestion of immediate loading to the neophyte, is questionable. If he showed this same scenario with an immediately loaded implant, over half of the responders would blame the bone loss on just that. Bv