AFTER SIX MONTHS FROM THE EXPLANTATION AND SINUS WALL RECONSTRUCTION WE PLACED THE IMPLANTS AT THE RECONSTRUCTED SINUS. WE NOTICED THAT THE SCHNEIDIRIAN MEMBRANE IT IS AGAIN IN PLACE. WE FOUND A NICE QUALITY OF BONE THAT ALLOW US TO PLACE THREE IMPLANT WITH A VERY GOOS STABILITY. THE REMAINING CONCAVITY WAS TREATED WITH A POLILACTIC ACID MEMBRANE.