Bone resorption after tooth loss due to trauma, periodontal or endodontic pathology is a frequent finding that complicates dental implant placement (Juodzbalys & Kubilius 2013, Sharan & Madjar 2008). In cases of severe bone resorption in the posterior maxilla, a so-called sinus augmentation procedure together with vertical and horizontal bone augmentation may be required to achieve an adequate 3D bone dimension. In the lower jaw, bone resorption can therefore result in insufficient horizontal and/or vertical volume. Also, the presence of the mandibular nerve limits the height of implant placement and sometimes requires vertical bone augmentation procedures prior to actual implant placement.

Maxillary and mandibular augmentation, vertical and horizontal, is usually performed using autogenous bone, bone substitutes or a mixture of both, such as bovine bone mineral (Esposito, et al. 2014). However, autogenous bone grafts are considered to be "the gold standard” (Sakkas et al. 2017). The success of autografts mainly depends on the graft osteogenicity (osteoinductivity), graft stability (osteoconductivity) and its adaptation to the recipient site (Hallman & Thor 2008; Misch & Dietsh 1993).

Different donor sites are used to harvest autogenous bone. Iliac crest and calvaria bone are identified as the most common extraoral sites. The mandibular ramus and symphysis are most often used as intraoral donor sites. Little is known about the differences between these types of bone. However, autogenous bone, especially harvested from the symphysis area (von Arx et al. 2005) and extraoral sites, in particular from the iliac crest (Hill et al. 1999, Loefer et al. 2012) has major drawbacks, such as considerable morbidity at the donor sites and patient discomfort and sometimes persistent side effects (von Arx et al. 2005).

Therefore, various alternatives to autogenous bone have been used clinically to achieve sufficient bone volume for implant insertion. The types of bone graft can be divided into: xenografts, such as bovine or porcine bone, and allografts, e.g., human bone, and synthetic bone. Different outcomes have been reported by different researchers. Papageorgiou et. al. (2016) stated in their systematic review, taking into consideration the limitations of the studies included such as inconsistency and the imprecision of the reported data, that no significant differences were found between xenografts and autogenous bone in the percentage of newly formed bone. Nevertheless, they stated that caution is advised when choosing the type of bone graft.

Beside the osteoinductivity, which is superior in the case of autografts, graft stability or osteoconductivity is an important factor in the success of bone augmentation. In general, deproteinized bovine bone (xenograft) is the most commonly used biomaterial for bone augmentation procedures for its osteoconductive properties (Artzi et al. 2001). Some suggest that a certain ratio of autogenous bone with xenografts could be beneficial to maintain sufficient osseoinductivity and osseoconductivity. For example, Kim et al. (2020) concluded that the use of xenografts, either alone or with autogenous bone at a proportion of 25%, showed superior dimensional stability compared to the exclusive use of autogenous bone.

As already mentioned, beside the osseoinductivity and osseoconductivity of graft materials, the adaptation and positioning of the bone block graft materials and the way the graft material is secured at the recipient site are crucial to the eventual success of the augmentation procedures. Different techniques and components have been utilized to secure the graft to the recipient site. Non-resorbable and resorbable membranes (Buser et al. 1996, Simion et al. 1998), fixation screws, (Misch et. al. 1997), dental implants (Triplet et al. 1996) or titanium mesh (Boyne et al 1997; von Arx et al. 1996) are most commonly used and described in the literature.

New technologies in bone augmentation procedures mostly focus on achieving optimal adaptation, improving the osseoinductivity of the biomaterials and enhancing post-operative healing. There are several developments in this field and a few of them have already found their way into clinical use, however with limitations. In this article an attempt has been made to explain three major recent developments, some of which are based on emerging technologies such as computer-aided design (CAD) and computer-aided manufacturing (CAM) and 3D printing:

1. Individualized bone graft: an individually designed allogenic bone block that attempts to enable complex horizontal and vertical augmentation using 3D CAD/CAM technology.
2. Individualized 3D printed titanium mesh: a custom-molded mesh, using 3D CAD/CAM technology, to individualize the commonly used titanium meshes to fit the defect shape and related anatomy. 
3. PRF: a second-generation platelet concentrate that represents the development of the therapeutic use of a platelet gel that aims to collect platelets, leukocytes, and related cytokines in a fibrin clot.