Allogeneic cortical struts and bone granules for challenging alveolar reconstructions: An innovative approach toward an established technique

Abstract

Objective: The shell technique is a well-established procedure for GBR with which extensive osseous defects can be predictably restored by using cortical bone struts harvested from various intraoral aspects. Recent publications have demonstrated comparable results for autologous and allogeneic bone grafts, whereas the evidence on allogeneic cortical struts remains limited. Clinical considerations: In this case series, we demonstrate the regeneration of five complex alveolar bone defects in four patients with subsequent insertion of fixed dental implants. In all cases, cortical struts made from human donor bone were applied in combination with allogeneic bone granules and collagen membranes. Conclusions: Similar to autologous cortical shells, the allogeneic struts functioned by creating an immobile container with which the osseous defects in all patients could be successfully restored, enabling placement of dental implants in accordance with the treatment plan. Even when the containers were solely filled with allogeneic granules, vascularized healthy tissue was present at re-entry, demonstrating the vast potential of these materials for applications in dentistry. Clinical significance: Especially when it comes to regeneration of complex alveolar bone defects, autologous bone grafts are often outlined as the only treatment modality. Here we show that innovative biomaterials like allogeneic bone grafts hold the potential to mimic the functions of autologous bone transplants and provide excellent clinical results without the requirement of a second surgical side for bone harvesting and no risk of donor-site morbidity.

The allogeneic shell technique for alveolar ridge augmentation: a multicenter case series and experiences of more than 300 cases

“…Re-investigation at implant placement demonstrated a sufficient bone remodeling and vascularization within the three-dimensional CP containers [53]. This can be confirmed by our histological findings.…”

“…A case series reported about 4 patients with alveolar ridge augmentation using CP, allogeneic granules and a porcine pericardium membrane. Re-investigation at implant placement demonstrated a sufficient bone remodeling and vascularization within the three-dimensional CP containers [ 53 ]. This can be confirmed by our histological findings.…”

A Novel Animal Model for Three-Dimensional Horizontal and Vertical Bone Regeneration Using Osseous Shell Technique: A Pre-clinical In-Vivo Study in Rabbits

“…In initially disclosed case reports, the integration of human allogeneic bone plates and autogenous bone chips seems to be a viable substitute to autogenous implants in complex bone augmentation procedures; that being said, these researches were often case-controlled cohorts with no proper comparative studies published in credible animal models for in-depth preclinical evaluation. [41,50,52] Several studies have reported the reduction bone resorption rate and modulation of bone turnover and formation by using barrier membranes over augmented bone blocks. [53] [45, 54] These adjunctive interventions prompt us more towards developing a reliable animal model to provide a solid biological basis for furher in-vivo testing of bone grafting techniques to optimize the clinical outcome.…”

“…[49] With the current usage of human allogeneic bone cortices, further intraoral or extraoral bone block harvesting can indeed be skipped, minimising the total risk of problems and patient morbidity while providing clinical outcomes equivalent to autogenous bone shells. [41,50,51] Several clinical report indicated favorable outcomes with human allogeneic bone blocks for bone grafting procedures conducted according to the osseous shell technique. [41,50] While there is little evidence on the use of xenogenic and allogeneic particulate bone material and blocks in various forms, there is much less on the use of allogeneic cortical plates for the shell approach.…”

“…[41,50,51] Several clinical report indicated favorable outcomes with human allogeneic bone blocks for bone grafting procedures conducted according to the osseous shell technique. [41,50] While there is little evidence on the use of xenogenic and allogeneic particulate bone material and blocks in various forms, there is much less on the use of allogeneic cortical plates for the shell approach. In initially disclosed case reports, the integration of human allogeneic bone plates and autogenous bone chips seems to be a viable substitute to autogenous implants in complex bone augmentation procedures; that being said, these researches were often case-controlled cohorts with no proper comparative studies published in credible animal models for in-depth preclinical evaluation.…”