Kurzfassung

Background: Vertical and horizontal alveolar bone loss after tooth extraction frequently limits the possibility of rehabilitation with oral implants. The preservation of the alveolar socket with bone-substitutes or augmented bone materials is an opportunity to prevent a collapse of the alveolar ridge and the loss of available bone volume for implant therapy. In order to prevent from bone loss during the healing phase the alveolar ridge can be stabilized by serveral techniques such as...Background: Vertical and horizontal alveolar bone loss after tooth extraction frequently limits the possibility of rehabilitation with oral implants. The preservation of the alveolar socket with bone-substitutes or augmented bone materials is an opportunity to prevent a collapse of the alveolar ridge and the loss of available bone volume for implant therapy. In order to prevent from bone loss during the healing phase the alveolar ridge can be stabilized by serveral techniques such as bone-substitutes in combination with collagen- or PEG-membranes. Since a high-quality ossification is crucially dependent of a sufficient and fast revascularization it might be possible to increase the blood vessel ingrowth and revascularization in the bone-substitutes by modifying them with Endothelial Progenitor Cells (EPC).
Hypothesis: Objective of our proposal is to evaluate the modificaton of a common bone-substitute (Cerasorb®) with human EPCs in order to effect a faster and more sufficient revascularization and a better ossification of the alveolar ridge in a nude rat model. We hypothesize a significant difference in revascularization and ossification as well as consequently in preservation of the alveolar socket between EPC modified bone-substitutes in combination with a polyethylene glycol (PEG) membrane (MembraGelTM, Straumann®) in comparison to the control group.
Methods: Our study design is based on an in-vivo model in nude rats, that has been established by our reseach group for this proposal. 20 nude rats will be splitted randomly in 2 groups. Each animal get removed one trepan (diameter 5.0mm; +/- 0.1mm) of compact and spongious bone layer from the occipital cranium calotte. The defect will be filled up with Cerasorb® that has been incubated in-vitro with a suspension of human EPCs for 24h. The control group receives just bone-substitute without EPC incubation. After 12 weeks, the refilled trepan defects including the bone-substitutes and the surrounding soft-tissues will be removed an analyzed respectively to the revascularization, the ossification and the vertical atrophy by histomorphometry and immunohistochemistry, micro-CT and three-dimensional corrosion casting.
 Perspectively we suspect less vertical atrophy and an increased revascularization and ossification by using a combination of EPC modified bone-substitutes and PEG-mebrane. We exspect to establish an alternative procedure in preservation of the alveolar socket and potentially for guided bone regeneration (GBR) as well, before intended implantation in order to optimate augmentation results for first-class outcomes.» weiterlesen» einklappen