Biologically Guided Flap Stability: the Role of Periosteum Retention on the Performance of the Coronally Advanced Flap

The design of the flap consisted of two horizontal beveled incisions (3mm in length) and two slightly oblique beveled incisions. The resulting trapezoidal-shaped flap was elevated in the coronal-apical direction. The suture of the flap started with two interrupted periosteal sutures performed at the most apical extension of the vertical releasing incisions; afterwards, it proceeded coronally with other interrupted sutures, each of them directed, from the flap to the adjacent buccal soft tissue, in the apical-coronal direction. The last sling suture allowed for the stabilization of the surgical papillae over the inter-dental connective tissue bed and allowed for a precise adaptation of the flap margin over the underlying convexity of the crown.