Comparison KS Versus TS

Number of Participants with implant failure

Defined as implant mobility and/or any infection dictating implant removal, and/or implant fracture and/or any other mechanical complication rendering the implant unusable. The stability of each individual implant will be measured by the local blinded outcome assessors manually tightening the screws with a torque of 30 Ncm at abutment connection at initial loading. At 1,3 and 5 years after loading, individual implants will be manually tested for stability. Once the single crowns will be screwed, their stability will be assessed by rocking the crown with the handles of two dental instruments.

Number of Participants with prosthesis failure

Whether it will not be possible to place the prosthesis because of implant failure or a prosthesis that has to be remade for any reason.

Number of complications

Technical (fracture of the framework and/or the veneering material, screw loosening, etc.) and/or biologic (pain, swelling, suppuration, peri-implantitis, etc.) complications will be considered.

Rate of peri-implant marginal bone level changes

Peri-implant marginal bone level changes will be assessed on periapical radiographs took with the paralleling technique at implant placement, at initial loading, 1,3 and 5 years after loading. Ideally digital radiographs should be taken, otherwise radiographs on conventional films will be scanned into TIFF format with a 600 dpi resolution, and stored in a personal computer. Peri-implant marginal bone levels will be measured using the Scion Image (Scion Corporation, Frederick, MD, USA) software. The software will be calibrated for every single image using the known distance of the first two consecutive threads. Measurements of the mesial and distal bone crest level adjacent to each implant will be made to the nearest 0.01 mm. Reference points for the linear measurements will be: the coronal margin of the implant collar and the most coronal point of bone-to-implant contact. Bone levels will be measured.

Valuation of patient satisfaction

Patients will answer the following questions (separately for each implant): 1. Are you satisfied with the function of your implant-supported prostheses? Possible answers: yes absolutely, yes partly, not sure, not really, absolutely not. 2. Are you satisfied with the aesthetic outcome of your implant-supported prostheses? Possible answers: yes absolutely, yes partly, not sure, not really, absolutely not. 3. Would you undergo the same therapy again? Possible answers: "yes" or "no".