When patients ask for tooth replacement in the esthetic zone, one of their priorities is a pleasing esthetic outcome. Besides white esthetics, the pink esthetics (Vermylen et al., 2003), made up by the color, shape and character of the marginal mucosa, are of great importance to the overall appearance. These aspects can be the reason why patient expectations are not fulfilled to the desired degree. An esthetic compromise can manifest itself in vertical recession in the midfacial or interdental area, loss of facial contours in the horizontal dimension and in differing tissue color or surface texture (Furhauser et al., 2005), which is one of the most significant disadvantages of immediate implants.

The main reason is the remodeling process of the surrounding tissues after tooth removal, for the most part resorption of the buccal tissues in the horizontal dimension (Botticelli et al., 2004b, Araujo et al., 2005, Schropp et al., 2003). Influencing factors can be related to tooth extraction, such as mechanical trauma, microorganisms in the socket from the oral cavity or disruption of the periosteal blood supply by flap elevation, or be patient-related, such as smoking habits or plaque accumulation (Tan et al., 2012). Two very important influencing factors are the thickness of the buccal bone wall and the loss of periodontium (Ferrus et al., 2010, Lee et al., 2014, Botticelli et al., 2004a).

Complete preservation or reconstruction of the peri-implant soft tissues remains one of the biggest challenges in implant dentistry. To counteract defect formation that negatively influences the esthetic appearance and the osseointegration of the implant, alveolar ridge preservation techniques and supportive measures have been considered and utilized to achieve the best possible esthetic result (Lin et al., 2014, Iasella et al., 2003, Vignoletti et al., 2012, Corning and Mealey, 2019). These include hard and soft tissue augmentation procedures, immediate provisionalization, flapless implant placement, a more palatal orientation of the implant in the socket and possibly the use of platform switching. Despite the positive effect of all these techniques it needs to be realized that an optimal esthetic result cannot be achieved in every case (Khzam et al., 2015) as the tissue changes cannot be completely prevented or compensated (Esposito et al., 2012, Chen and Buser, 2014, Lin et al., 2014).

Loss of the periodontal ligament and the bundle bone plays a major role influencing the resorption process that leads to peri-implant soft tissue recession and esthetic deterioration. As these structures are lost, the buccal bone plate and the covering soft tissues thin out and even reduce in height because the bundle bone extends into the tip of the buccal bone wall. In the maxillary anterior region, the coronal part of the buccal lamella often consists of bundle bone only, and therefore its loss leads to a complete resorption of the buccal bone in this area (Araujo and Lindhe, 2005). It has become obvious that primary prevention of tissue loss by preservation of the bundle bone would be a key factor to esthetic success.