The dynamics of bone augmentation with a TiO2 graft material: Studies in challenging pre-clinical models

Abstract

Diseases like caries and periodontitis can often lead to tooth loss. This will subsequently lead to resorption of the alveolar bone surrounding the tooth. In cases where the tooth is too be replaced with a dental implant, it can therefore be challenging to find enough bone to place the implant. There are several methods to augment bone by the use of surgical techniques and biomaterials. One type of materials are bone graft materials, which can act as a scaffold for new bone formation. The gold standard is to use autologous bone, however this is limited by the available amount and requires a second intervention with increased morbidity. Other alternatives are allogeneic and xenogeneic bone grafts, from other humans and other species respectively. However, these materials need thorough processing to avoid disease transfer, but the process also removes osteogenic cells. Additionally, there are ethical and religious concerns using materials from human and animals. A final group of materials are alloplastic materials. These are synthetically made, and can be for example polymers, metals or ceramics. This thesis evaluated the use of a TiO2 scaffold for bone augmentation. TiO2 is a porous ceramic with similar mechanical strength to bone. It has previously shown promising results in pre-clinical studies. In the present thesis, the TiO2 scaffold was tested in challenging pre-clinical models. In the first study, the TiO2 scaffold was placed around an implant placed in a jaw with insufficient bone volume, and in he second study the scaffold was placed on top of a jaw which has resorbed following tooth loss. Histology, immunohistochemistry, X-ray microtomography and 3D scanning were performed. The results demonstrated bone growth within the porous structures of the TiO2 scaffold, also in these challenging models. However, the amount of new bone formation was not more than the control groups. The immunohistochemical results indicated potential for further bone growth which might not have been achieved within the time period tested.