Retrospective analysis of 10,000 implants from insertion up to 20 years—analysis of implantations using augmentative procedures

Abstract

BackgroundA sufficient amount of bone is essential to ensure long-term stability of dental implants. To support the bone regeneration process, different techniques and materials are available. It has been questioned whether these techniques and materials may compromise implant survival compared to pristine bone. To properly answer this question, long-term stability up to 20.2 years after insertion of implants placed in augmented or non-augmented sites was retrospectively analysed.MethodsRetrospective analysis included 10,158 implants from 3095 patients in three private practices who underwent implant therapy with or without bone augmentation procedures. Different graft materials and membranes were used for augmentation. If necessary, the graft was stabilised using a titanium mesh. Implant survival was evaluated analysing explantation rates and Kaplan-Meier survival curves in augmented or non-augmented sites. In additional subgroup analyses, augmentation procedures, graft materials and membranes were compared applying descriptive statistics.ResultsThe observation period varied from the day of implantation up to 20.2 years after implant insertion. The overall implant survival was 95.5% (augmented sites 96.33%; native sites 94.27%). Comparison of Kaplan-Meier survival curves revealed significantly better survival of implants in augmented sites (p = 0.0025). When comparing different augmentation procedures, the best results were found for bone condensing followed by lateral augmentation. Graft materials were used in 58.2%, membranes in 36.6% of all implant sites. The most often used graft materials were a deproteinized bovine bone mineral (53.0%) and autogenous bone particles (32.5%). Both provided the best results and showed a significantly better implant survival compared to no graft material using the Kaplan-Meier method (p = 0.0104 and p < 0.0001). A native collagen membrane was used most often (74.0% of the membrane sites) and provided the best results regarding implant survival in the log-rank test.ConclusionsThe retrospective analysis shows that implants inserted in augmented or native bone demonstrate similar implant survival under the conditions of private practice compared to prospective studies. To establish a broad base of support, further well-designed clinical trials are necessary.

Bilateral maxillary augmentation using CAD/CAM manufactured allogenic bone blocks for restoration of congenitally missing teeth: A case report

“…Allogenic bone grafts also have an excellent safety profile, as a World Health Organization initiated study demonstrated no reports on transmission of any kind of infectious diseases associated with freeze‐dried bone allografts (FDBA) . Furthermore, the increasing demand for implant‐borne prosthesis is concordant with rising numbers of bone augmentation procedures, as these are often required to provide sufficient bone quantity prior to or with installation of a dental implant …”

“…[24][25][26][27][28] Furthermore, the increasing demand for implant-borne prosthesis is concordant with rising numbers of bone augmentation procedures, as these are often required to provide sufficient bone quantity prior to or with installation of a dental implant. 5,6 Clinical data on the survival and success rates of allogenic bone blocks are excellent, ranging from 93.7% to 100%, however, allogenic bone blocks were reported to be more technique-sensitive and susceptible to infection when compared to autografts. 17,22 Complications reported with the application of allogenic bone grafts are almost exclusively related to contaminations, which can occur either during the adaptation of blocks to the defect's geometry, or, because of improper soft-tissue management resulting in membrane exposure, incision line opening and perforation of the mucosa.…”

“…For proper fixation of dental implants, however, an adequate amount of bone is required. Despite the introduction of short and diameter‐reduced implant systems, which represent an implant‐based approach to overcome limitations in bone volume, an augmentation of the alveolar crest is often necessary …”

Bone grafts: which is the ideal biomaterial?

“…Bovine xenografts play a major role and have been proven for cranio‐maxillofacial applications (Yamada & Egusa, ) with no reports on Transmissible Spongiform Encephalopathies (TSE) and Bovine Spongiform Encephalopathy (BSE) risk (Kim, Nowzari, & Rich, ). Results from a large retrospective analysis with long‐term observation time (Knofler, Barth, Graul, & Krampe, ), together with a systematic review of survival data, indicate that synthetic graft materials are associated with lower dental implant survival rates than bovine cancellous bone substitutes (Aghaloo & Moy, ). Nevertheless, in randomized control clinical trials (Mardas, Chadha, & Donos, ; Mardas, D'Aiuto, Mezzomo, Arzoumanidi, & Donos, ) with a synthetic bone substitute or bovine xenograft, both types of BGs presented similar radiographic alveolar bone changes when used for alveolar ridge preservation.…”

“…Therefore, a very commonly used source of bone matrices is animal‐derived bones; bovine xenografts, distantly followed by equine and porcine, are commonly used in clinical practice. Bovine‐derived cancellous BGs are acknowledged as the closest xenograft to human bone to be regenerated, second only to autografts (Datta, Gheduzzi, & Miles, ; Athanasiou et al., ), and are considered safe products that can be used daily in clinical practices where bone regeneration is needed in reconstructive surgeries (Capanna et al., ; Knofler et al., ). However, necessary cleaning and sterilization processes for starting, raw materials of animal origin result in the decay of both mechanical and biological performances (Vishwakarma, Sharpe, Shi, & Ramalingam, ).…”