The aim of this case series is to demonstrate the efficacy and safety of this novel augmentative procedure for ridge preservation prior to implant therapy. This shall serve as a basis for a prospective study.

In all four cases, patients showed a stable volume of soft and hard tissues after the augmentation with AutoPD and good osseointegration of titanium implants, having been placed in this augmented socket.

The application of autologous bone and xenogeneic biomaterials for alveolar bone augmentation following tooth extraction has been intensively studied. This so called ridge preservation aims at the prevention of bone atrophy. From a biological point of view, autologous bone is still considered to be the optimal augmentation material due to its osteogenic, osteoinductive and osteoconductive properties [1, 34]. However, especially in small defects, possible donor-site morbidity, limited graft volume availability and additional length of operation for harvesting autologous bone led to the increasing usage of xenogeneic biomaterials such as demineralized bovine bone substitute (DBBS—Bio-Oss^©). These kind of non-resorbable biomaterials have great potential in maintaining the dimension of the contour of the ridge by serving as a framework for new bone formation [7]. Although DBBS shows great osteoconductive potential and has been proven to be as effective as autologous bone alone or in combination with autologous bone, it has a slow and incomplete resorption rate [4, 14, 22, 24].

In addition, the use of DBBS increases treatment cost and may be incompatible to some patients. Regarding these factors of influence, it is of interest to test alternative bone substitute materials.

In traumatology, many studies showed that replanted teeth with a devitalized periodontal tissue will ankylose and dentin will be replaced by bone [1, 3].

It is well known that dentin and bone have a similar organic and inorganic structure [21]. Recent studies have focused on dentin as a potential bone substitute in different models of alveolar defects. It could be shown that dentin, being used either as a block graft or in particulated form, is involved in bone remodelling, expressing osteoconductive and even osteoinductive properties [3, 5, 9, 26, 29, 30]. In vivo studies in mice showed that dentin scaffolds performed similar with regard to the inflammatory response and neovascularization compared to isogenic bone [9]. Both materials induced an acute short-term inflammatory response with increased leukocyte-endothelial cell interaction, a process often observed after the implantation of biomaterials [19, 27]. Additionally, in vitro studies showed that protein extracts from dentin affect proliferation and differentiation of osteoprogenitor cells. Results suggested that TGFβ and perhaps other factors in dentin can regulate cell behaviour and, therefore, can influence development, remodelling and regeneration of mineralized tissues [33].