Fig. 1

Radiographs showing measurements of bone heights (bone edges, marginal and sinus floor, with white lines) using the first coronal thread as reference point R (red dots). a post-operative; b after 6 months; c after 2 years; d after 6 years; e after 10 years. Legend: R = reference point (first coronal thread of the implant); AM = apical measurement (distance between R and the sinus floor); CM = coronal measurement (distance between R and the marginal bone edge). Note: For reason of clarity R, AM and CM are sketched at two implants. The complete measurements (mesial and distal) were performed for all implants. In the radiograph c) it can be seen that the implants are still not loaded. In some cases incorporation of final prostheses was prolonged due to participants’ causes, e.g. financial restrictions