RCT GBR One Stages Comparing A-Oss and Autogenous Bone Versus A-Oss and LCR-A

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

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.

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

CBCT scans will perform before ridge reconstruction and six months after. The Digital Imaging and Communication in Medicine (DICOM) data will export the OnDemand 3D software version 1.0.9.3223 (Cybermed Inc., Seoul, Korea) to perform all measurements. The DICOM data were manually alined basic on unchanged anatomical areas (e.g., teeth, basal skull, implants) and then automatically matched using the Fusion adjunctive module (Cybermed Inc. Seoul, Korea). Horizontal bone measure will recorded for all reconstructed ridge 2 mm below the bone crest, before and after treatment. Then, the postoperative volumetric data were subtracted to the original scenario. The new generated set of DICOM data will stored as a separately files. Volumetric measurements of grafts were performed with OnDemand 3D software (Cybermed Inc., Seoul, Korea) using the previously generated set of DICOM data.The volumes of the grafted material will calculated using automatic tools, basing on its opacity.

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.

Plaque index (PI), defined as plaque absent or present (0/1), and Bleeding on Probing (BoP), defined as bleeding on probing absent or present (0/1), will recorded 1,3 and 5 years after final prosthesis delivery. One assessor, not previously involved in the study, made all the clinical outcomes.

Patients will answer the following questions (separately for each implant):

• Are you satisfied with the function of your implant-supported prostheses? Possible answers: yes absolutely, yes partly, not sure, not really, absolutely not.
• Are you satisfied with the aesthetic outcome of your implant-supported prostheses? Possible answers: yes absolutely, yes partly, not sure, not really, absolutely not.
• Would you undergo the same therapy again? Possible answers: "yes" or "no".1) Are you satisfied with the function of your implant-supported prostheses? Possible answers: yes absolutely, yes partly, not sure, not really, absolutely not.

• Are you satisfied with the aesthetic outcome of your implant-supported prostheses? Possible answers: yes absolutely, yes partly, not sure, not really, absolutely not.

• Would you undergo the same therapy again? Possible answers: "yes" or "no".

The soft tissue biotype will be investigated by the same surgeon at the surgical procedures using a periodontal probe into the sulcus. Greater will be the thickness of the tissue, smaller will be transparency of the periodontal probe. The amount of keratinized tissue will be evaluated 1 year after surgical procedures using a periodontal probe. This outcome will be evaluated according to the distance from the gingival margin to the mucogingival junction

Esthetic evaluation of occlusal and vestibular pictures will take every years after definite loading was done following the pink esthetic score (PES). In brief, the PES score evaluates seven variables: mesial papilla, distal papilla, soft tissue level, soft tissue contour, alveolar process deficiencies, soft tissue color and texture. A 0-1-2 scoring system was used, 0 being the lowest and 2 being the highest value, with a maximum achievable score of 14 per dental unit.