Date Published: January 8, 2020
Publisher: Springer International Publishing
Author(s): Carlo Mangano, Andrea Bianchi, Francesco Guido Mangano, Jessica Dana, Marco Colombo, Ivan Solop, Oleg Admakin.
To present the application of custom-made 3D-printed subperiosteal implants for fixed prosthetic restoration of the atrophic posterior mandible of elderly patients.
Between January 2017 and June 2018, all partially edentulous patients aged over 65 years, with two or more missing teeth in the posterior atrophic mandible, and who did not want to undergo bone regenerative procedures, were included in this study. These patients were rehabilitated with custom-made subperiosteal implants, designed from cone beam computed tomography (CBCT) and fabricated in titanium by means of direct metal laser sintering (DMLS). The outcome measures were fit and stability of the implants at placement, duration of the intervention, implant survival, and early and late complications. All patients were followed for 1 year after surgery.
Ten patients (four males, six females; mean age 69.6, SD ± 2.8, median 69, 95% CI 67.9–71.6) were included in the study. The fit of the implants was satisfactory, with a mean rating of 7 out of 10 (SD ± 1.6, median 7, 95% CI 6–8). Only two implants had insufficient fit, because of the presence of scattering in the CBCT; however, they were adapted to the sites during the interventions. The mean duration of the intervention was 44.3 min (SD ± 19.4, median 37, 95% CI 32.3–56.3). At the one-year follow-up, no implants were lost (survival rate 100%). One implant presented immediate postoperative complications with pain, discomfort and swelling, and two patients experienced late complications, having their provisional restorations fractured during the temporisation phase. All these complications were minor in nature, but the final complication rate amounted to 30% (three of ten patients).
Although this study has limits (small patient sample and short follow-up), DMLS has proven to be an effective method for fabricating accurate subperiosteal implants, with high survival rates. This may represent an alternative treatment procedure in elderly patients with a severely atrophic posterior mandible, since it allows avoidance of regenerative bone therapies. Further studies are needed to confirm these outcomes.
Subperiosteal dental implants appeared in Sweden and the United States in the middle of the last century [1, 2]. Subperiosteal implants were custom-made fixtures, inserted below the periosteum, and stabilised by contact with the underlying bone, by means of fixation screws and the fibro-mucous tissue that covered them [2–4]. They were usually made of cobalt-chrome or titanium alloys and were prosthetised by means of transmucosal abutments that emerged inside the oral cavity [3, 5].
Between January 2017 and June 2018, 15 partially edentulous patients with missing teeth in the posterior mandible were considered for inclusion in this study, for treatment with subperiosteal DMLS implants. Five were excluded: three were under 65 years old and two were smokers. Therefore, ten patients (four males and six females) were included. These patients were aged between 68 and 75 years (mean age 69.6, SD ± 2.8, median 69, 95% CI 67.9–71.6).
Subperiosteal implants have existed for many years and, until the advent of modern implantology ad modum Brånemark, were a solution for the prosthetic rehabilitation of partially and completely edentulous patients [1–5, 38–40]. Although some scientific works demonstrated long-term survival of these implants [41–43], and that osseointegration was indeed possible [42, 43], for various reasons they were abandoned and replaced in modern implantology with endosseous implants [6–8, 42, 43].
In the past, subperiosteal implants represented a possible solution for prosthetic restoration of the atrophic posterior mandible. However, their use presented several technical and surgical issues (including the need for two surgical sessions, and often poor adaptation to the surgical site) that were in part responsible for the high percentage of complications in the short and long term.