Reimplantation Followed by Peri-implantitis
and Bone Regeneration in a Type 1 Diabetic

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.”

core vent implant
In the left mandible, she had fractured off the abutment of an old core vent implant and the crown of the adjacent tooth which was deemed unrestorable by her restorative dentist. This patient presented with a right bridge that was soon to fail and a mandibular left quadrant that needed to be restorated to function ASAP. It was decided to remove both the implant and the bicuspid and place two implants.

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.

After the surgery was completed, the radiograph showed an unacceptable mesial angulation to the molar implant. Because there was no membrane used, a probe was inserted into the incision line. The hex for the molar implant was located and the implant was up-righted using a perio probe.
3 months after placement, the implants are integrated and healing abutments are placed. On the molar, note the position of the mandibular nerve and also the density of the marginal bone. While the implant is integrated after being floated in Socket Graft, there is a significant distance for the regenerative cells to migrate and crestal mineralization is not yet complete.
After placement of healing abutments, the patient was referred back for a final check. The crestal mineralization on the molar had progressed to the collar of the implant and the degree of mineralization around the floated molar is higher than the density of the bone around the bicuspid implant.
The final photograph of the finished case. The patient then went on to replace the failing right mandibular bridge.

This case teaches us that when using SteinerBio graft material, you do get integration in the area of the graft site on immediate implants. All other graft materials, including all cadaver bone grafts, have been shown to fill the defect, but not integrate to the implant surface. While we have learned from this case, it still has a lot to teach us. Ten years later, the patient was referred back for a failing implant in the mandibular left quadrant.
10 years after placement. Contrary to what you are thinking, it was not the implant that was floated in the Socket Graft material. Instead, it was the bicuspid that was failing. This was a simple, easy predictable implant with little question about its long term success. The diagnosis is periimplantitis, but why did this implant fail when the challenging molar implant is still perfect after 10 years?
The crown was removed, but the abutment was left in place. The plaque, calculus, and extensive bone loss is obvious. Pay attention to the position of the implant. It appears from this view that the implant is placed to the buccal.
Evaluation of the lingual gives us the reason for this implant failure. Due to the buccal placement of the implant, the abutment was built with a lingual ledge, making the lingual surface of the implant virtually uncleanable. After 10 years of bacterial accumulation, peri-implantitis had progressed to the point of implant failure.

This implant failed for two reasons: The first mistake was the placement of the implant and the second mistake was building an unhygienic abutment. The decision was made to regenerate the bone loss and create a cleansable restoration. The most important step for regenerating bone on a surface contaminated with plaque and calculus is to clean the surface completely. Any residual inflammatory residue will result in failure of bone to migrate to and integrate to the implant surface.

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.

The implant surface was cleaned with air abrasion using a βTCP powder developed specifically for the purpose of cleaning implant surfaces. The powder is called OsseoConduct Micron produced by SteinerBio. The surgery was performed on 12/06/19. Note that the bone porosities are filled with the micron powder. Air abrasion will drive the particles into the bone and also will remain on the implant surface. For this reason, a resorbable βTCP powder is ideal for this process.
12/06/19

The site was grafted with Ridge Graft Kit, which is a combination of our putty and our OsseoConduct βTCP granules. The site was covered with a Teflon membrane.
12/06/19

Because the implant was 10 years old, we did not have a cover screw to place under the membrane. As a result, the decision was made to perforate the membrane and place a healing abutment through the membrane.
12/06/19

Day of surgery. Note the graft density. Because the putty has not been invaded by cells and vascular tissue, the graft appears as dense as the surrounding bone.
01/02/20

Three weeks after grafting. The graft now has less density as regenerative cells and vascular supply invade the graft site.
01/16/20

Five weeks after grafting shows the maximum loss of graft density as the βTCP particles are obvious. However, the density is increasing at the base of the graft as mineralization of this area increases.
01/16/20

The healing abutment is removed and a portion of the membrane is exposed.
01/16/20

Membrane removed 5 weeks after grafting.

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.

03/13/20

At three months, the surgical site is exposed to gain access to the microthreads for removal and polishing and evaluate the graft site. The ridge is well mineralized with resorption of the putty portion of the graft, which is replaced by mineralized bone, but many βTCP granules remain.

While resorption of the βTCP granules will occur, it is initially very slow while it is encased in the newly formed woven bone. Rapid resorption of the graft material occurs when the bone is loaded and the bone remodels into lamellar bone. The patient was referred for restoration.
05/29/20

The restorations were placed approximately 1 month after removal of the microthreads. This radiograph was taken approximately one month after the restorations were placed.
A magnification of the prior radiograph shows the graft site with increased density and nearly complete resorption of the βTCP granules, except at the mesial crest.
05/29/20

The restoration shows a reduced lingual contour allowing for proper oral hygiene.

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.

Successive Reimplantation of Dental Implants Into Sites of Previous Failure
J Oral Maxillofac Surg 2020 Mar;78(3):375-385

Results: The survival rate of the implants placed in the sites of previous failure (first reimplantation) was 77.4% (137 of 177 implants). A statistically significant difference was found (P = .0001) between the survival rates of implants placed for the first time and implants placed into sites of previous failure. The survival rate of the second reimplantations was 72.7% (16 of 22). The survival rate of the third reimplantations was 50.0%.
A Retrospective Analysis of Replacing Dental Implants in Previously Failed Sites

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:

The patient was referred for a failing implant. The appearance of the granulation tissue and surrounding bone indicated that the site had been grafted. Upon contact with the treating dentist, it was confirmed that an allograft was placed in the extraction socket prior to implant placement. The diagnosis was bone graft failure.
Upon reflecting the flap, bone granules can be seen within the granulation tissue. In periimplantitis, like periodontal disease, the bone is resorbed ahead of the infection and no bone fragments are found in the granulation tissue. In bone graft failure, the bone breaks up and fragments of bone are found in the granulation tissue. Therefore, the diagnosis was confirmed as bone graft failure.
The bone graft and implant had been in place for a number of years before the graft failed. As mentioned earlier, the sclerotic bone formed when grafting with cadaver bone causes a much larger area of sclerotic bone than the initial extraction socket. In this photograph, after dramatic bone removal, cadaver bone particles are encased in sclerotic bone that are still visible. Sclerotic bone has virtually no vascular supply. As you can see, the mesial portion of the bottom of the socket is not bleeding and more sclerotic bone needs to be removed.
The sclerotic bone created by the cadaver bone graft is fully removed, but only the buccal and lingual cortical plate remain, and the bone removal approached the cribriform plate of the adjacent teeth.

The site was grafted with Socket Graft, an implant was placed, and the new implant has been functioning for a number of years.

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