The treatment indications were single or multiple tooth replacement in the maxilla or mandible without the use of simultaneous augmentation or membrane, of which the implants were to be restored with either fixed single crown or fixed partial denture restorations.

Treatment procedure

Patients were to be treated according to standard practice for implant procedures applicable in the countries participating in the study. Implants used in this study were CAMLOG SCREW-LINE implants (K-Line) with diameters of 3.8 mm, 4.3 mm, 5.0 mm (or 6.0 mm), and lengths of 9 mm, 11 mm, and 13 mm. Both platform-matching and platform-switching abutments could be used. The protocol allowed freedom of choice, and the investigators selected the best option for the patients’ indication. Implants were placed following normal treatment protocols of the participating site and were inserted following one-stage or two-stage surgery decided upon clinical need. Implants were restored after a healing period of at least 6 weeks post-surgery in bone class I–III and 12 weeks in bone class IV [25]. During surgery, the bone quality, crestal ridge width and height, and primary stability of the implant were documented.

Follow-up

The post-surgical examination took place between 1 and 2 weeks post-surgery according to the standard practice. At this time, patient complaints and adverse events were recorded. Patients underwent suture removal and were instructed in oral hygiene and plaque removal. Follow-up visits were scheduled according to standard practice and according to the surgical protocol. Patients undergoing two-stage surgery attended a re-entry surgery for placement of the healing abutment; otherwise, patients attended the clinic for abutment placement, provisional prosthesis placement, and definitive prosthesis placement as per individual treatment plan. Follow-up appointments then occurred at 6 months, 1, 2, 3,4, and 5 years post prosthetic installation. Standard maintenance care like check-ups for dental hygiene was performed as required.