Implant-supported Rehabilitation of Atrophic Edentulous Sites With a Novel, Simplified Technique for Bone Augmentation or Soft Tissue Augmentation: a Randomized Trial

The primary aim of the present study is to compare the Sub-periosteal Peri-implant Augmented Layer (SPAL) technique and soft tissue augmentation (STA), performed simultaneously to implant placement, in terms of (i) implant survival rate and (ii) health/disease condition of the peri-implant tissues at 6 and 12 months following implant loading. The secondary aim of the project will be to compare the SPAL technique and STA in terms of intra- and post-operative morbidity.

The study is designed as a single-blind, parallel-arm, randomized clinical trial. Patients will be recruited and treated at the Operative Unit of Dentistry, Azienda Unità Sanitaria Locale (A.U.S.L.) of Ferrara, Italy, and one University center (Research Centre for the Study of Periodontal and Peri-implant Diseases, University of Ferrara, Italy). Each patient will contribute the study with one sextant ("experimental sextant"). Each eligible patient will be randomly assigned to receive SPAL technique or STA according to a computer-generated randomization list. Surgical procedures will be performed by experienced periodontal and implant surgeons. Two calibrated, blinded examiners will take care of the assessment of clinical and radiographic parameters, Case Report Form (CRF) filling, as well as data extraction from CRFs for the preparation of the study database.

The proportion of patients free from peri-implantitis at 12 months following loading will be the primary outcome variable of the study. The proportion of patients with complete resolution of the bone dehiscence (BD), dimensional variations and 12-months characteristics of BD, and patient-reported outcome measures will be the secondary outcomes. The design will test two hypotheses, with a non-inferiority trial in terms of primary outcome and a superiority trial in terms of secondary outcomes.