A subject that has been discussed lately is the high failure rate of reimplantation after an implant is removed. In our clinic, if an implant needs to be removed, we do not experience a high failure rate. The case below showcases how advanced technology can solve many of our most challenging problems.
Patient presented with a failing right posterior mandibular bridge. The bridge was still functioning, but had a hopeless prognosis. She was scheduled for removal of the bridge, extraction of one of the supporting teeth, and placement of two implants. When she presented for the surgery, she said, “Doc, I just broke off two teeth on the left and you cannot take the bridge out because if you do I will not be able to chew properly and as a result, I will not be able to control my diabetes. You need to fix the left side first.”
Reimplantation Followed by Peri-implantitisand Bone Regeneration in a Type 1 Diabetic
The extraction of the bicuspid was uneventful. An extra long non-serrated bur was used to remove bone around the coronal portion of the implant. However, when the threads on the collar of the implant were passed and the basket portion of the implant was reached, the implant was loose. In the area of the basket of the implant (the core, if you will) there was no bone contact and only granulation tissue was encountered.
The resulting osteotomy for the posterior implant was much wider and longer that any of our implants, in addition to being close to the mandibular nerve. A standard immediate implant was placed into the bicuspid and grafted with Socket Graft. The osteotomy for the molar implant was grafted with Socket Graft and the implant was floated in the osteotomy with no bone contact. No membrane was used and the gingiva was closed with primary closure.
During the development of OsseoConduct Micron βTCP powder, multiple failed implants were tested for surface purity. Post air abrasion with OsseoConduct™ βTCP Micron produced a negative result, indicating an endotoxin level below 0.25EU/ml, which is within the acceptable limits for new medical devices as determined by the FDA.
03/13/20
3 months after grafting, mineralization of the graft is occurring and many of the graft particles are reducing in size as resorption occurs at the base of the graft site.
05/29/20
There were no probing defects and no inflammation. However, a lack of keratinized gingiva is noted. After additional time for healing, a gingival graft will likely be required.
This case required a wide array of advanced science-based products and procedures that cannot be accomplished with traditional materials and methods. Although there was no bone contact on the molar implant and the implant was immediately replaced, the case resulted in excellent bone regeneration in a Type 1 diabetic for the duration of 10 years. Studies that have evaluated failure rates for reimplantation have assessed all the possible factors from systemic disease, age, and various medications and have found that nothing correlates to reimplantation implant failure. The consensus from these studies is that the failure rate for reimplantation is “site specific”. The term site specific is code for saying the bone that supports the implant is the problem.
Let’s review two recent studies done by skilled experienced oral surgeons. The studies were both retrospective studies done in private oral surgery offices and both groups were university affiliated professors. The studies did an extensive review of the patients’ diseases, medications, smoking, etc. Neither study found any systemic correlation to implant failure. Both authors conclude the reason for reimplantation failure is site specific. This means ‘in that site only’. Other implants in the same patients were successful, so the problem is not the patient’s bone in general, but it is the bone that supports the failed implant that is the problem. These two identical studies had significantly different success rates for reimplantation as you can read below.
Oral Surg Oral Med Oral Pathol Oral Radiol 2012 Sep;114(3):290-3
Results: Survival rate of the implants replacing previously failed ones was 93% (133/144). A third placement in the same site was performed in 7 of 11 patients with a survival rate of 85% (6/7) up to the last follow-up. No correlations were found between replaced implant failures with any of the parameters examined.
Both studies list the overall success rate for initial implant placement, but this is worthless information. These are retrospective studies done on implants placed in specialty offices. They place the implant and never see the patient again. The only failures they know about are the ones that are sent back to them. What about the people who have moved, or did not want the implant replaced, or wanted to go to a different clinician? While the reported initial implant success rate is of no use, the reimplantation group should provide reliable data.
So, what is the difference between the two studies? In the first study, with poor success rates, every implant was removed and grafted with an allograft and waited months before reimplantation. In the second study, only 7% of the removed implants were grafted and waited for reimplantation. In the second study with the high success rates, the only factor that statistically correlated with implant failure was bone grafting (p=.008).
Did you catch that?
We just read that the high success rate study stated: “No correlations were found between replaced implant failures with any of the parameters examined.” Why does the author denying his own findings? Perhaps because the results are too hard a pill to swallow.
These two studies confirm that the more you graft a site with cadaver bone, the higher the failure rate. What is remarkable is that in the study with the high failure rate, the clinician continued to do the same procedure with the same cadaver bone grafts with increasingly higher failure rates! While he concludes the problem is with the bone, there is no discussion or thought that it may be the cadaver bone that is causing his “site specific” problem. The reason the author cannot allow himself to even consider that the site specific problem is caused by cadaver is 1) everything our professors know about cadaver bone grafts is wrong and 2) bias. Neither author of either study could bring themselves to even consider that the problem could be cadaver bone graft. When an implant fails in a site grafted with cadaver bone graft, there is a way to avoid repeated implant failure. You must remove the cadaver bone graft that caused the failure in the first place, but you also need to understand that the amount of bone you need to remove is much larger than the original socket. The sclerotic bone that is formed is also outside the grafted socket, and in order for healthy bone to grow, all of the sclerotic bone needs to be removed. The following case describes the process:
