Caroliene Meijndert

36 Chapter 2 in a number of patients with a visible titanium border of the implant cervically of the crown. The scores of the ICAI at T 120 was 5.8, with an acceptable result in only 59% of the patients. It appears that ICAI has a very stringent scoring system with penalty points for small deviations from the ideal situation. Also in other studies, in which ICAI was used, low levels of acceptable results were found: 66.7% for mucosa and 75% for crowns in the study of Santing et al. (2013); 56.5% for mucosa and 62% for crowns in the study of Den Hartog et al. (2013). In contrast with the slightly diminishing results of the aesthetic index, overall patient satisfaction was 8.6 (on a scale from 0 to 10), with 98.6% of the patients satisfied at the 10-year evaluation, which favourable score is in line with the literature (Gotfredsen, 2012; Schropp & Isidor, 2015). Apparently, patients are very satisfied with single tooth replacements by implant restoration in the aesthetic zone, notwithstanding the fact that professionals experience implant treatment in the aesthetic region rather challenging and are not always satisfied. At the T 120 months’ evaluation 19 patients were lost to follow-up due to moving to another part of the country or changing address without notice. Drop-out was unevenly distributed over the treatment groups (2 non-attendance in the group with chin bone, 7 non-attendance in the group with chinbone and membrane, and 10 non-attendance in the group with a bone substitute and membrane). The assumption was made that non-attendance was independent of treatment result and patient satisfaction. However, drop-out could have had an effect. Few long-term studies on dental implant treatment in the aesthetic region are available. Moreover, different evaluation parameters are used and patient centred outcomes are not always present. Therefore, it is difficult to get insight in the true long- term clinical performance of dental implants and dental implant restorations and to compare different clinical procedures. Since volume of soft tissue and underlying bone buccal of dental implants is of most importance in the aesthetic region, investigators should strive to include evaluation of these tissues in studies. Buccal bone is also not an item in the present study. Standardized analysis of radiographs made with cone beam computer tomography could possibly help to get information on buccal bone, although it is recognized that presently insufficient resolution and metallic artifacts influence detection of small changes in bone volume (Kuchler et al., 2016).