Lateral Sinus Floor Elevation in Cases of an Intact and Perforated Schneiderian Membrane

The study comprised 20 lateral sinus floor elevation cases performed in 18 patients. During surgery, in four cases, a perforation of the Schneiderian membrane was detected. An attempt to suture the perforated membrane may increase the risk of enlarging the perforation. Therefore, we suggest a more conservative protocol be applied in all four cases where perforation occurred. The procedure consists of the 3-layer technique: an absorbable oxidized cellulose gauze moisturized with Dicynone was placed in this area. Under it, as a second layer, a PRF membrane is applied and then covered with a slow-resorbable collagen membrane. At that point, the surgery continues with the placement of the bone substitute material, and the sinus-lifting is finalized according to the selected protocol. The clinical studies demonstrate that the bone graft has a slower healing rate in areas with perforation, which is a proof of the osteogenic properties of the Schneiderian membrane. The cases described reveal that using this surgical protocol is risk-free and has a high success rate.