Two Studies Find One Reason
for Implant Failure

Large medical institutions continually evaluate the success or failure of medications and therapy with the purpose of identifying the most effective therapy at the lowest cost. Today we will review two such studies, one performed at the Mayo Clinic, and one performed at an institution in China. Both studies were remarkably extensive looking at all medications, all diseases, and such factors as smoking to identify what factors were associated with implant failure.
Early Implant Failure Associated With Patient Factors, Surgical Manipulations, and Systemic Conditions
J Prosthodont. 2019 Jul;28(6):623-633. doi: 10.1111/jopr.12978. Epub 2018 Oct 22.
Among 8,540 implants identified during the study period, 362 (4.2%) failed within the first year of placement at a mean (SD) of 129 (96) days after placement.

After adjustment for age, sex, and implant area, no single or multiple medical condition(s) and no single or multiple medication(s) increased patient risk of implant failure in the first year after placement other than socket grafting with cadaver bone grafts.

  • Socket preservation (HR, 2.67; 95% CI, 1.33-5.38; p = 0.006)
  • Xenogenic material (HR, 2.12; 95% CI, 1.11-4.04; p = 0.02)

Virtually every patient factor, procedural factor, and material factors were evaluated and only one factor was found to be significantly associated with implant failure after one year and that was preimplant socket preservation with the use of cadaver bone and particular Bio-Oss. A higher percentage of patients had socket preservation with autografts and there was no effect on implant failure. This study concludes that socket preservation does not negatively affect implant performance, but only the use of cadaver bone graft materials for socket preservation results in implant failure.

One study does not establish scientific fact. However, when another study is performed by a separate group doing the same study and produces the same results, we can accept the findings as factual. That second study has now been published as follows:
The risk factors of early implant failure: A retrospective study of 6113 implants
Clin Implant Dent Relat Res. 2021 Jun;23(3):280-288. doi: 10.1111/cid.12992. Epub 2021 Mar 16.

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.

Successive Reimplantation of Dental Implants Into Sites of Previous Failure
J Oral Maxillofac Surg. 2020 Mar;78(3):375-385. doi: 10.1016/j.joms.2019.10.001. Epub 2019 Oct 13.
Unfortunately, when a cadaver bone graft produces sclerotic bone, the alveolar bone is compromised forever and either removing the implant and allowing the site to heal or re-grafting with any graft material will not improve the health of the surrounding sclerotic bone. At SteinerBio, we have developed a method of rehabilitating sites grafted with cadaver bone grafts and we will present this method in a future article.

Cadaver bone grafts look good clinically because they blend in with the existing bone, but our professors and lecturers do not understand what is happening biologically. Our professors in US dental schools have been promoting cadaver bone grafts for the last 30 years and they are unable to accept that cadaver bone grafts are inferior to modern science-based bone grafts, so it will be up to the clinician to force change.


American Society for Bone and Mineral Research (ASBMR)

Tissue Engineering and Regenerative Medicine International Society (TERMIS)