Caroliene Meijndert

81 Alvoalar ridge preservation in defect sockets in the maxillary aesthetic zone Introduction Immediate implant placement is frequently advocated for a single failing tooth in the maxillary aesthetic zone. However, in some cases after tooth extraction, the future implant site is inadequate for primary implant placement (Buser et al., 2004; Chen & Buser, 2009). Examples of inadequate sites for immediate implant placement are large bone deficiencies, severe recession of the mucosa and extensive infection (Jung et al., 2018). Just removing the tooth and let the alveolus heal without extra precautions, can often lead to progressive physiologic resorption of the buccal bony wall (Araújo et al., 2019). A few techniques have been described to avert this ‘physiologic collapse’ of the alveolar ridge after tooth extraction, including alveolar ridge preservation (Jung et al., 2018). Alveolar ridge preservation cannot stop the resorption process, but it can reduce the degree of alveolar alteration (Chappuis et al., 2017; Tonetti et al., 2019). This is particularly important in the aesthetic region where the alveolar bone supports the mucosa, which determines a great deal of the aesthetic outcome of an implant restoration. The Jung et al. (2018) systematic review noted that alveolar ridge preservation has clear advantages in preserving alveolar ridge volume in the aesthetic region. There is a wide range of dental implant designs, one of which is a tapered implant body. In 2018, Jokstad and Ganeles defined a tapered implant as a cylindrical implant where the endosseous part narrows in diameter toward the apex (Jokstad & Ganeles, 2018). A possible benefit of a tapered implant design is improved primary stability compared to parallel-walled implants (Atieh et al., 2018; Sugiura et al., 2019). Improved primary stability is particularly important in low density and soft bone, and in healing extraction sockets. Furthermore, it is said that there is less risk of bone fenestrations in anatomical undercuts at the apical part of tapered implants, as is often present with the maxillary alveolar processes (Atieh et al., 2018). Good results have been achieved with tapered implants in the aesthetic region including implant survival, bone level change and aesthetic outcome, both in preserved and in non-preserved sites (den Hartog et al., 2013; Slagter et al., 2016; Eghbali et al., 2018; Zuiderveld et al., 2018). Various tapered implant brands are available. In 2015, a new line of tapered implantswas launched (Straumann Bone Level Tapered implant, Institut Straumann AG, Basel, Switzerland). It has a tapered body, converging from the cervical part towards the apex, and is further equipped with the established characteristics of previous designs of the same manufacturer, such as a SLActive surface (Smeets et al., 2016) and platform switch with conical implant/abutment connection (Hsu et al., 2017). To the best of our 5