Soft Tissue Responses Around Nanostructured Calcium-phosphate-coated Implant Abutments on Dental Implants: Histological, Genetic and Clinical Evaluation in Smokers and Non-smokers.

* Baseline: * Standard preparation of the osteotomy * Placement of 2 dental implants * On each implant one of both types of healing abutments is placed * Suturing * Standardized radiography to measure bone-levels at baseline * Digital impression of the surrounding gingiva with an intra-oral scanner (a non-invasive method) to measure the baseline level of the gingiva * 2 weeks after Baseline: o Removal of the sutures * 4 weeks after Baseline: * A 2nd digital impression of the soft tissue with an intra-oral scanner * Collecting crevicular fluid by placing paperpoints in the provided apertures in the healing abutments for 60 seconds without bleeding. * Measuring of the pocket depth in the provided apertures in the healing abutments with an automated probe. * Removal of the Healing Abutment with the attached soft tissue en-bloque. * Placement of a new, regular, Encode Healing Abutment. * 10 weeks after Baseline: * Start of standard prosthetic procedure. In this study we expect that the soft tissue attachment (i.e. the gingival attachment) will be stronger and earlier achieved at the nano-structured healing abutments than at the normal, uncoated healing abutments. This would lead to a more stable soft tissue complex on the long rung and thus providing a more predictable aesthetic outcome. Secondly, a stronger attachment would mean a stronger barrier against micro-organisms and might influence the occurrence of peri-implantitis.