Implant-supported Rehabilitation With SPAL Technique or Soft Tissue Augmentation

In patients assigned to the SPAL group, the management of the soft tissues will be performed according to the SPAL technique as originally described by Trombelli et al. (2018). Implant site preparation will be performed using a set of calibrated guided surgery steel burs under copious sterile saline irrigation. Implants will be placed, and a healing abutment will be positioned and screwed. The space underneath the periosteal layer will be then filled with a deproteinized bovine bone mineral (DBBM) graft. A sterile viscoelastic gel (SVG) based on polynucleotides and hyaluronic acid (REGENFAST®, Mastelli Srl, Sanremo, Italia) will be combined with the bone graft. The periosteal layer will be then secured to the oral flap by mean of 6/0 resorbable internal mattress sutures. SVG wil be placed underneath the mucosal layer and the latter will be coronally advanced and stabilized a using 6/0 resorbable internal mattress and sling sutures.

In patients assigned to the STA group, flap management will be performed as described by Stefanini et al. (2016). Implant site preparation will be performed according to the same procedures described for the SPAL group. SVG will be placed underneath the buccal flap and the latter will be then released from tension by means of periosteal and muscular incisions, and will be coronally advanced and adapted to the healing abutment with a 6/0 resorbable sling suture. Interrupted sutures will be used to accomplish primary intention closure in the interproximal areas.