Novel Osteogenic Ti-6Al-4V Device For Restoration Of Dental Function In Patients With Large Bone Deficiencies: Design, Development And Implementation

Abstract

Custom devices supporting bone regeneration and implant placement are needed for edentulous patients with large mandibular deficiencies where endosteal implantation is not possible. We developed a novel subperiosteal titanium-aluminum-vanadium bone onlay device produced by additive manufacturing (AM) and post-fabrication osteogenic micro-/nano-scale surface texture modification. Human osteoblasts produced osteogenic and angiogenic factors when grown on laser-sintered nano-/micro-textured surfaces compared to smooth surfaces. Surface-processed constructs caused higher bone-to-implant contact, vertical bone growth into disk pores (microCT and histomorphometry), and mechanical pull-out force at 5 and 10 w on rat calvaria compared to non surface-modified constructs, even when pre-treating the bone to stimulate osteogenesis. Surface-modified wrap-implants placed around rabbit tibias osseointegrated by 6 w. Finally, patient-specific constructs designed to support dental implants produced via AM and surface-processing were implanted on edentulous mandibular bone. 3 and 8 month post-operative images showed new bone formation and osseointegration of the device and indicated stability of the dental implants.

Performance of laser sintered Ti–6Al–4V implants with bone-inspired porosity and micro/nanoscale surface roughness in the rabbit femur

“…Previous studies have shown differences in bone healing around hydroxyapatite implants placed in rabbits up to 6 months after implantation [26]. Work from our group has also shown varied response to additively manufactured implants at 5 weeks compared to 10 weeks [13]. It may be possible that differences in healing occurred at an earlier time point, but stabilized for both implants after 10 weeks.…”

“…This model is also more relevant than the calvarial bone onlay model, providing the ability to evaluate response to an implant size that could be used clinically. While vertical cortical bone formation had been previously observed in the cranial bone onlay model in rats, it was unclear how osseointegration would occur horizontally within trabecular bone [13]. For orthopaedic implants and for dental implant placement in the mandible, the ratio of cortical to cancellous bone contributes to primary stability and long term success [23, 24].…”

Custom-Made Direct Metal Laser Sintering Titanium Subperiosteal Implants: A Retrospective Clinical Study on 70 Patients

“…In the case of elderly patients with very pronounced bone atrophy, the placement of endosseous implants via bone regenerative techniques may be unwise [13, 42–44]. Such patients may have general (medical) health problems, or may simply not want to pursue a treatment option involving multiple invasive procedures (e.g., hip grafting), the risk of complications and postoperative pain, and increased cost and time of treatment, simply to gain stability and increase masticatory function to that of a complete removable denture [10, 13, 15, 16, 42–44].…”

“…DMLS is an additive manufacturing (AM) method for creating patterns using thermal fusing (sintering) of powdered metals [40–44, 48]. DMLS models are generated directly from 3D computer data converted to STL files, which are then sliced into thin layers (typically about 0.1 mm/0.004 inches) using appropriate software.…”

“…The use of such modern fabrication techniques allows us to revisit some of the past techniques, such as subperiosteal implants, and reinterpret them in a modern and digital way [44]. This can be extremely useful in the case of severe bone atrophy, which does not allow for the placement of endosseous dental implants if a regenerative intervention approach is not followed, particularly in the case of elderly patients with limited financial resources and who do not wish to undergo long and complex regenerative surgeries prior to the insertion of endosseous dental implants [44]. …”