The present study was retrospective, but they followed every patient in the study through to restoration.
The implants were placed between 2015 and 2019. Overall, 6,113 implants in 3,785 patients were included. There was a statistically significant increase in failed implants in the maxillary posterior region and implants placed in sockets grafted with Bio-Oss. No patients received autografts, allografts, or synthetic graft materials.
Again, this study evaluated every medication, every systemic disease, smoking and all possible factors involved in the implant placement.
Both studies had a significant number of implants that were grafted at the time of implant placement, and this was not a factor in implant failure.
Both studies concluded that of all the patient and treatment variables, the only variable that was associated with implant failure was the use of cadaver bone grafts for socket preservation. This finding is easily explained. Socket preservation is the only bone grafting procedure where the implant is placed exclusively in grafted bone. In all other grafting procedures, the implant is always partially in native bone, and this is the critical factor.
Another important finding of the Mayo Clinic study is that socket grafting with autografts did not negatively affect implant success rates. This finding is just as important as knowing that cadaver bone grafts increase implant failure. Autografts are resorbed and produce normal bone. Any graft material that resorbs and produces normal bone does not negatively affect implant success rates. All bone grafts that do not resorb negatively affects implant success rates and this includes non-resorbable synthetic bone grafts, all allografts, and all xenografts. The reason why these graft materials reduce the success rate of dental implants is because they all produce sclerotic bone that does not remodel and any structure that does not remodel and repair will fail over time.
The FDA will not clear any bone graft that does not resorb and remodel and result in normal bone and this is the reason no allograft, xenograft, and non-resorbable synthetics have been cleared for implant placement. The only bone grafts cleared by the FDA for implant placement are Socket Graft, Sinus Graft, and those bone grafts containing our OsseoConduct βTCP granules. Socket Graft and Sinus Graft have been cleared for implant placement after 8 weeks and grafts containing OsseoConduct βTCP granules have been cleared by the FDA for implant placement in 6 months because that is the time period where all graft material is resorbed in humans. SteinerBio bone grafts are the only bone grafts proven to result in implant integration and there is no science that shows implants integrate in sites grafted with cadaver bone grafts.
We have been warning the profession about the high rate of implant failure when grafting sockets with cadaver bone graft materials for over 10 years. Any clinician can prove this to themselves by simply looking at their failures and finding out if the site was grafted with a cadaver bone graft material. We have been doing this for over 10 years and our findings are that approximately 50% of all implant failures have been grafted with a cadaver bone graft.
One of the referenced studies found a strong association with implant failure and implants placed in the posterior maxilla. This has been reported and is accepted by most clinicians. This bone is commonly weak with poor mineralization and defined as type 4 bone. To overcome the high failure rate of implants placed in the posterior maxilla, clinicians are increasingly filling the osteotomy with BioDensification at the time of implant placement. This product stimulates mineralization and improves bone quality during the integration process.
Another topic that needs discussing is how dentistry defines bone quality. The dental profession defines bone quality on the hardness of the bone. The harder the bone, the higher the bone quality. This system may be acceptable for non-augmented sites, but cadaver bone produces sclerotic bone that is hard and high in mineral content and the most common site of implant failure. Hardness is not an acceptable method of defining bone quality. The development of an accurate system of determining bone quality will be of significant value to the dental profession.
Dentistry has studied bone grafting procedures extensively for 40 years, but the profession has not studied bone biology or bone graft biology and because of this, the profession knows very little about the bone we are placing our implants in and even less about the bone that we create when a bone graft is placed. For the last 20 years, SteinerBio has exclusively studied bone biology and bone graft biology and we do understand the bone that we place our implants in as well as the type of bone that is created by not only our products but also how cadaver bone grafts mineralize and fail. Because of this body of knowledge, we do not need studies to document the failure of cadaver bone grafts because we continually see it in the clinic. Eliminating cadaver bone grafts from your practice will eliminate the single principal cause of implant failure.
Cadaver bone grafts do not fail because they are more susceptible to periimplantitis. Cadaver bone grafts (and non-resorbable synthetics) breakup and any infection is secondary. However, cadaver bone graft failure is always misdiagnosed as periimplantitis. Bone graft failure is easy to distinguish from periimplantitis because you will see granules in the granulation tissue radiographically with a quality digital radiograph. We suggest all clinicians study the radiographs of all failed implants closely and they will begin to recognize the granules and then make an accurate diagnosis of bone graft failure. Different non-resorbable bone grafts fail with different radiographic characteristics, but that subject cannot be covered here. For more on this subject please see the following articles:
A study on implant failure found the following regarding using allografts for socket grafting:
Every time an implant fails in a socket grafted with an allograft, the incidence of the replacement implant failing in the future is significantly increased up to a 50% failure rate.
