Caroliene Meijndert

9 General introduction hydroxyapatite) (Campana et al., 2014). The augmented site can be covered with a membrane and a mucosa graft when needed. Post-extraction sites with a buccal bone defect When considering implant therapy for replacement of a single tooth, it is advisable to start planning before the failing tooth is extracted. One of the techniques that is used to avert the risk of post-extraction alveolar ridge resorption is alveolar ridge preservation. (Jung et al., 2018). The goal is to reduce the dimensional changes that occur after tooth extraction, by applying a bone graft and/or a bone substitute in the extraction socket, so that the implants can be placed in a prosthetically ideal position (Jung et al., 2018; Wessing et al., 2018). Alveolar ridge preservation does not stop the resorption process, but it can slow down the degree of alveolar alterations before implant placement (Chappuis et al., 2018; Tonetti et al., 2019). This is particularly important in the aesthetic region. The alveolar bone supports the peri-implant mucosa, and the peri-implant mucosa is essential for a good aesthetic outcome. Therefore it can be assumed that alveolar ridge preservation has a beneficial effect on the aesthetic outcome (MacBeth et al., 2017; Jung et al., 2018; Chappuis et al., 2018). Post-extraction sites without a buccal bone defect Nowadays, immediate implant placement after tooth extraction is frequently advocated for. This approach is less time consuming than the conventional procedure and leads to increasing patient contentment (Joshi & Gupta, 2015). Studies have shown that immediate implant placement and restoration after tooth extraction has a comparable outcome to that of conventional implant placement and restoration protocols when the conditions are favourable (Esposito et al., 2017; Slagter et al., 2014). A key condition for the success of the immediate implant placement and restoration approach is primary stability (Papaspyridakos et al., 2014). Primary stability limits micromovement and allows osteogenic cells to adhere to the implant surface, leading to osseointegration (Rodrigo et al., 2010). However, it is influenced by a number of factors such as the quality and quantity of the bone, surgical techniques, and the micro and macro design of the implants (Rao & Gill, 2012, Smeets et al., 2016). But when primary implant stability is achieved, and a bony defect of the buccal bone plate is absent, or present as small solitary defects at most, immediate non-occlusal provisionalization is possible (Slagter et al., 2014; Van Nimwegen et al., 2018). 1