Caroliene Meijndert

11 General introduction switch or a platform match. It has been suggested that an internal implant-abutment connection with a conical configuration is the most stable connection, with less bacterial leakage than the other configurations (Zipprich, 2018). This might lead to less bone loss compared to a non-conical connection (Schmitt, et al., 2014). Because the aesthetic outcome of restorations in the aesthetic region is of major importance, it is important to assess if an implant-abutment connection has any influence on the clinical, radiographic and aesthetic outcome of an implant restoration. So far, only Vetromilla et al. (2019) performed a systematic review on implant abutment connections in the aesthetic region. They concluded from the Pink and White Esthetic Scores that the internal hexagon performed better aesthetically, but they were not able to quantify their observations. Additionally, they did not distinguish between platform- switched and platform-matched connections. According to Caricasulo et al. (2018), the presence of a platform switch might be an important contributing factor in reducing peri-implant boneloss. Thus, when studying the outcome of different connection types, analysing platform switched connections separately from platform matched connections might be a determining factor (Hsu et al., 2017; Caricasulo et al., 2018). General aim and outline of the thesis The general aim of this thesis was to assess the outcomes of treating a single missing tooth in the aesthetic region with an implant, hereby assessing the short and long term outcome. The patients in the various studies described in this thesis had different grades of alveolar bone resorption. A variety of dental implant designs within the portfolio of one implant brand were applied. The specific aims were: − to assess the 10-year clinical, radiographic, aesthetic, and patient centred outcomes of a tissue level implant system placed in augmented sites comparing three different augmentation techniqes ( Chapter 2 ); − to assess the 5-year clinical, radiographic, aesthetic, and patient centred outcomes of a bone level cylindrical implant system in healed sites ( Chapter 3 ); − to assess the 1-year clinical, radiographic, aesthetic, and patient centred outcomes of a bone level tapered implant system in unassisted healed sites ( Chapter 4 ); − to assess the 1-year clinical, radiographic, aesthetic, and patient centred outcomes of a bone level tapered implant system in preserved healed sites ( Chapter 5 ); − to assess the 1-year clinical, radiographic, aesthetic, and patient centred outcomes of a bone level tapered implant system in post-extraction sockets ( Chapter 6 ); 1